Download SECTION 16410

SECTION 16410
415 HZ POWER SYSTEM
410.01
GENERAL
A.
Overview
The work covered by this Section consists of furnishing, installing,
connecting, testing and placing in operation a continuous duty,
regulated, 415 HZ, 208 volts AC, 3-phase, 3-wire power system for
selected computer equipment loads. The system shall be fully
coordinated and compatible with electrical, environmental and space
conditions at the site.
The 415 HZ power system shall consist of frequency converting
equipment and distribution equipment. The frequency converting
equipment shall be either of the following:
1.
Static Frequency Converter consisting of a rectifier/battery
charger, batteries, invertor, synchronizing equipment, protective
devices and automatically effect continuity of 415 HZ electric
power within specified tolerances to the 415 HZ computer
equipment load, without interruption, regardless of the condition of
the normal 60 HZ power supply. In the event of normal power
supply failure, continuity of power to the load shall be maintained
for an emergency period of up to 3 minute with the inventor
supplied by the batteries, to allow orderly shutdown of the
computer equipment. If an alternate power source is available,
such as standby engine generator set, the static frequency
converter shall operate as an uninterruptable power system (UPS)
to provide continuous power to the computer equipment.
2.
Motor Generator Set consisting of 60 Hz AC motor, 415 Hz AC
generator, controls and accessories as specified herein. Motor
and generator rotors shall be stacked on a common shaft and the
motor and generator starters shall be contained in a single frame.
Paralleling equipment shall be provided where multiple frequency
converting equipment are used for the same system.
415 Hz power distribution equipment shall consist of feeders,
distribution panels, branch circuit wiring and computer equipment
connections.
B.
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Manufacturer
1.
Static Frequency Converter shall be as manufactured by Emerson
or Exide.
2.
Motor Generator Set shall be as manufactured by Kato or G.E.
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C.
Material
All materials shall be new and listed by the Underwriters Laboratories,
and shall meet their requirements and bear their label wherever
standards have been established or shall show evidence of approval
by an acceptable independent testing laboratory, and shall conform to
the applicable specifications and standards of the Institute of Electrical
and Electronics Engineers (IEEE), American National Standards
Institute (ANSI), Joint Industry Committee (JIC), Insulated Power Cable
Engineers Association (IPCEA), National Electrical Manufacturers’
Association (NEMA), and National Fire Protection Association (NFPA).
Canadian equivalent listing and standards are acceptable.
Materials and workmanship are subject to approval by the Engineer.
Any portion of the work, which, in the judgement of the Engineer, is
defective shall be replaced by the Contractor as part of this Contract,
at no additional cost to HGST.
Each component shall be of current manufacture from a firm regularly
engaged in the production of such equipment. The bidder shall submit
with his proposal, a list of three (3) installations of motor-generator sets
or static frequency converters engineered by the bidder, which have
been installed within the past three (3) years and are operating
satisfactorily, and which use major components of the same or similar
type as the bidder proposed to furnish.
D.
Submittals
Provide complete manufacturer’s descriptive information and shop
drawings for all equipment, material, and devices to be furnished. The
shop drawings shall include certified outline drawings, arrangement
drawings, construction details, schematic diagrams, interconnection
and connection diagrams in accordance with provisions in these
documents.
Manufacturer’s standardized diagrams will not be accepted unless
applicable portions of the diagram have been clearly identified and
nonapplicable portions deleted or cross out.
The following drawings and information shall be submitted with the
proposal:
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1.
Single line diagram depicting the system configuration. All circuit
breakers shall be identified by location, type, catalog number,
frame size, trip rating and manufacturer with type number.
2.
Functional relationship of various equipment including weights,
dimensions, heat dissipation and detailed foundation requirement
of each unit.
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3.
Detailed descriptions of equipment to be furnished. Any
deviations from these Specifications shall be submitted during bid
period.
4.
Size and weight of individual shipping units to be handled by
Contractor in the field.
Detailed layouts of all metering and alarm panels. The metering
sensing points shall be shown on the single line diagram.
5.
6.
Equipment delivery time in calendar days.
The following drawings and information shall be submitted within
30 days after award of Contract.
1.
Detailed installation drawings including all terminal locations.
2.
Interconnect wiring diagrams showing all conduit runs and wiring
with terminal numbers for each wire.
A test report showing that the equipment has passed the factory tests
and has demonstrated the full output ratings required by this
Specification shall be submitted 7 calendar days prior to delivery of the
equipment.
E.
Instruction and Operating Manuals
Subsequent to final completion and testing operations, instruct HGST
designated personnel in operation, adjustment and maintenance of the
415 Hz power equipment.
Submit four (4) complete sets of instruction and operating manuals.
The manuals shall include a functional description of the equipment
with detailed block diagrams, safety precautions, step-by-step
instruction of operating and maintenance procedures, seismic and
foundation details, and a list of recommended spare parts.
F.
Warranty
The contractor shall provide HGST a one year warranty. The warranty
period starts upon written documentation that the 415 Hz power
system is functioning properly and is accepted by HGST.
This warranty shall cover all defects in materials, equipment and
workmanship, but will not cover theft, Acts of God, or any defects that
occur due to malicious behavior. All repairs and replacement costs of
defective items during the warranty period shall be borne by the
Contractor.
410.02
DESCRIPTION OF STATIC FREQUENCY CONVERTER
A.
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Operation
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The utility company power source shall be used to supply power to
each rectifier/charger unit. The rectifier/charge shall be solid state and
shall covert incoming AC power to DC power. The rectifier/charger
output shall be fed into a solid state invertor. The invertor shall convert
the DC power into 415 Hz AC power which shall supply the load.
Upon failure of input AC power, input power for the invertors shall
automatically be supplied from the battery with no interruption to or
disturbances of the system output in excess of the limits specified
herein. At the same time, the system shall energize an alarm circuit
and associated trouble indicators. When the AC power is restored,
input power for the invertors and for recharging the battery shall
automatically be supplied from the rectifier/charger outputs without
interruption of disturbances in excess of limits specified herein. If the
battery is exhausted before AC power returns, the system shall
shutdown automatically.
B.
Configuration
The static frequency converter system shall consist of two or more
modules of the same size operating in parallel. All modules shall be
operating and sharing the load. The system shall be redundant. The
system shall have one additional module than that required to supply
the full rated load. The failure of any one of the modules shall cause
that module be disconnected from the system by its static isolator and
the remaining module(s) shall continue to carry the load. Upon repair
of the module, it shall be reconnected to the system to resume
redundant operation. Any module shall also be capable of being taken
off the system manually for maintenance without disturbing the system
bus.
The system shall include system control cabinet, controls, metering,
alarms and batteries.
C.
Rating
The static frequency converter shall be sized to provide a minimum
output KVA and KW as shown on the Drawings, with one system
module out of service.
The utility input voltage shall be 480 VAC, 60 Hz three-phase, threewire. The output voltage shall be 208 VAC, 415 Hz three-phase, threewire.
The static frequency converter system shall have an efficiency of not
less than 82%.
The static frequency converter shall have necessary filters to prevent
malfunction of the electronic master clocks system caused by system
interference.
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D.
E.
Input Characteristics
1.
Voltage Range
+/-10%
2.
Frequency Range
+/-5%
3.
Current In-rush Limiting
Gradually increase input
current from 20% to 100% of
full rated load over 15
seconds.
4.
Magnetizing Sub-cycle Inrush
8 times normal full load input
current maximum.
5.
Power Factor
0.83 to 0.95 lagging at full
load.
6.
Current limit
Maximum of 125% normal
full load input current.
7.
Harmonic Feedback
Maximum 10% RMS total.
Output Characteristics
1.
Voltage Regulation
+/-0.5% for balanced load,
+/-2% for 50% unbalanced
load.
2.
Voltage Adjustment Range
+/-5% manually
3.
Frequency
Frequency Regulation
415 Hz
0.1%
4.
Phase Displacement
Balanced Loads
50% Unbalanced Loads
120 +/-1
120 +/-3
5.
6.
Voltage Unbalance
- Balanced Load
-
20% Unbalanced Load
+/-1% from the arithmetic
average of the 3 phases
-
50% Unbalanced Load
+/-2% from the arithmetic
average of the 3 phases
Voltage Transients (in percent of rated voltage)
(1) 20% Load Step
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+/-1% from the arithmetic
average of the 3 phases
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(2) 30% Load Step
+/-5%
(3) 50% Load Step
+/-8%
(4) Loss of return of AC input power +/-1%
F.
7.
Voltage Transient Recovery Time
To within 1% of output
voltage rating within 50
milliseconds.
8.
Harmonic Content
Maximum 5% RMS total,
Maximum 3% any single
harmonic
9.
Overload with full Voltage
125% of its full load rating for
a period of 10 minutes 150%
of the full load rating for a
minimum of 30 seconds
10. Current Limit
150% full load current
11. Fault Clearing
Instantaneous clearing of the
fault current greater than
300% and limit the fault
current to within 500% of
normal full load current.
Environmental Conditions
The static frequency converter system shall be capable of withstanding
any combination of the following external environmental conditions
without mechanical or electrical damage or degradation of operating
characteristics:
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1.
Operating ambient temperature:
System Module
0C to 40C
Battery
25C +/-5C
2.
Nonoperating and storage ambient temperature:
-20C to 70C
3.
Relative humidity 0% to 95% for temperature in the operating
range without condensation.
4.
Barometric pressure:
Operating
-
From 0 to 4,000 feet
above sea level
Nonoperating & storage
-
From 0 to 4,000 feet
above sea level
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G. Audible Noise
Noise generated by the static frequency converter system under any
condition of normal operation shall not exceed the allowable sound
pressure level of 75 dB measured at 6 feet from the nearest surface of
the cabinet.
H.
Grounding
The static frequency converter AC neutral and ground system shall be
connected together at a common ground point. The equipment
chassis shall be provided with a ground bus.
I.
Efficiency
The efficiency of the system is to be measured under the following
conditions:
J.
1.
The system is operating at full rated load, KVA and KW.
2.
The battery is fully charged and floating on the system.
3.
The input voltage is within the specified range.
4.
Efficiency is defined as the output KW times 100 divided by the
input KW, and shall be 82% minimum.
Rectifier/Charger Unit
The Rectifier/Charger unit shall include but not limited to the following
components:
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1.
Each rectifier/charger unit shall be solid state and shall provide
direct current to the invertor unit for battery charging.
2.
Each rectifier/charger unit shall be provided with an input circuit
breaker. The circuit breaker shall be of the frame size and trip
rating to supply full rated load to the 415 Hz computer equipment
load and recharge the battery at the same time. The circuit
breaker shall be provided with an UNDERVOLTAGE trip so that
the circuit breaker will open automatically when the control voltage
is lost. The circuit breaker shall have an interrupting rating of, not
less than, 22,000 symmetrical RMS amperes.
3.
A dry type power transformer of the isolated winding type shall be
used for each rectifier unit. It shall be of copper wiring exclusively
and have one 5% tap below and one 5% tap above rated voltage.
The transformer’s hottest spot winding temperature shall not
exceed the temperature limit of the transformer insulation class of
material when operating full load at maximum ambient
temperature of the transformer location within the rectifier/charger
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unit. The transformer shall be designed for continuous operation
at rated KVA with maximum temperature rise of 80C in a 40C
maximum ambient and 30C average ambient. If the transformer
has two secondary windings, they shall be connected delta-delta,
phase shifted 180 apart to reduce input harmonics.
K.
4.
Each rectifier/charger unit shall provide for input current limiting
and battery recharge current limiting. Both shall be independently
adjustable. The input current limit shall be adjustable for 100% to
125% full load. The battery recharge current limit shall be
adjustable from 2% to 25% of the maximum discharge current.
5.
The rectifier/charger unit shall provide features whereby when the
AC power is turned to the AC input but after the static frequency
converter system has been operating on battery power or has
been de-energized, the total initial power requirement at the input
terminals will not exceed 20% of rated load, and the power will
gradually increase to 100% of full rating over a 15-second time
interval.
6.
Power semiconductors in the rectifier/charger shall be fused with
fast acting fuses, so that loss of any one power semiconductor will
not cause cascading failures. All fuses shall be provided with a
blown fuse indicator with an alarm light on the control panel.
7.
The rectifier/charger unit shall have an output filter to minimize
ripple current into the battery. Under no conditions shall ripple
current into the battery exceed 3% RMS. The filter shall be
adequate to ensure that the DC output of the rectifier/charger will
meet the input requirements of the invertor. Each static frequency
converter system module shall have the capability of having the
invertor operated from the rectifier with battery disconnected.
8.
In addition to supply power for the load, the rectifier/charger shall
be capable of recharging the battery as specified herein. The
charging rate shall be sufficient to restore the batter from
discharge to 95% charge within ten (10) times the discharge time.
After the battery is recharged, the rectifier/charger shall maintain
the battery at full charge until the next emergency operation.
9.
There shall be DC over voltage protection so that if the DC voltage
raises to the pre-set limit, the system module will shutdown
automatically.
Inverter Unit
1.
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Each invertor unit shall be a solid state device capable of
accepting the output of the rectifier/chargers or battery and
providing rated output within specified limits.
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L.
2.
The invertor shall be able to sustain an overload across its output
terminals of up to 150% load, while supplying any load within its
rating, without reducing the output voltage. The invertor shall limit
current for any loading over 150% rated load by reducing the
output voltage. The invertor shall be capable of supplying at least
300% current during short circuit conditions. If the short circuit is
sustained, the invertor shall shutdown and disconnect
automatically from the system bus.
3.
The output frequency of the invertor shall be controlled by an
oscillator. The oscillator shall be temperature compensated and
capable of being adjusted +/-15 Hz of rated frequency. The
oscillator shall hold the invertor output frequency to +/-0.1% during
a 24 hour period. Total frequency deviation, including short time
fluctuations and drift, shall not exceed +/-0.1% from the rated
frequency.
4.
Electronic control shall be incorporated to provide individual phase
voltage compensation to obtain phase balance under all
conditions up to 50% load unbalance.
5.
For increased reliability the invertor shall be limited to a 6-pole
type using a maximum of 12 main power SCR’s.
6.
Each invertor unit in the system shall have fault sensing and static
isolation as well as an output circuit breaker for removal of a
faulted mode from the system, without affecting the critical load
bus beyond the stated limits.
7.
For parallel operation, all invertor units shall automatically load
share at all times. The output currents of individual system
modules shall be not more than +/-5% unbalanced.
8.
Power semiconductors in the invertor shall be fused with fast
acting fuses to prevent cascading the failures. Each fuse shall be
provided with a blown fuse indicator with an alarm light on the
control panel.
Protection
1.
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Each static frequency converter system module shall have built-in
self-protection against over voltage power line surges, under
voltages and over current introduced by the primary AC source,
over voltage and voltage surges introduced at the output terminals
by paralleled sources, load switching and circuit breaker operation
in the distribution system. Each system module shall be selfprotected against over current, sudden changes in output load and
short circuits at the output terminals.
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415 HZ POWER SYSTEM
2.
Each system module shall have built-in protection against
permanent damage to itself and the connected load for all
predictable types of failures within itself and the connected load
for all predictable types of failures within the system.
3.
Fast-acting current limiting devices shall be used to protect
against failure of solid state devices. Internal failures in a system
module shall cause the module to trip off-line with minimum
damage to the module and to provide maximum information to
maintenance personnel regarding the reason for tripping. Open
protective devices shall be indicated by appropriate lights (LED
type) on the control mimic panel(s).
4.
Under parallel redundant operation, the protection system shall
have control logic capable of isolating only the faulted module,
and shall not shut down the entire system for a fault in one
module.
M. Module Control Section
N.
1.
Each static frequency converter system module shall be provided
with a control section to provide monitoring and control of the
system module. The meters, alarms, controls and mimic panel
shall be located on the control section door. The control logic
shall be located in the control section, physically barriered and
separated from all heat sources and high voltage hazards. The
control fuses shall likewise be located in a separate section
behind a hinged door to minimize electrical shock, hazards.
2.
There shall be two (2) power supplies for the logic and control
circuits for each system module, one connected to the input AC
power source and the other connected to the system module
output. Battery operated power supplies for control will not be
permitted.
Module Instrumentation
The following meters shall be provided for the static frequency
converter system.
1.
Input voltage and current meters with phase selector switch.
2.
DC battery charge/discharge current meter.
3.
DC battery voltage meter.
4.
Inverter output voltage and current meters with phase selector
switch.
All system module meters shall be 4 ½ inch square, switchboard type
with an accuracy of at least 2%.
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415 HZ POWER SYSTEM
O. Alarm Indicator
Each static frequency converter system module shall include, as a
minimum, the following alarm indicators. Any one of these conditions
shall also turn on the appropriate summary indicator and audible alarm
on the system control panel.
1.
2.
3.
4.
5.
6.
7.
8.
P.
Fuse Blown
Overload
DC Over voltage
Equipment Overtemperature
Low Battery Shutdown
Battery Circuit Breaker Open
Fan Failure
Control Power Failure
Controls
Each system module shall include, as a minimum, the following
controls:
1.
2.
3.
Lamp test/reset pushbutton
Battery circuit breaker trip pusbutton
Inverter output circuit breaker trip pushbutton
Q. Mimic Panel
Each system module shall have a mimic panel in the format of a
module single line diagram with status indicators for input, output, and
battery circuit breakers. Each circuit breaker shall have two (2) lights,
one lit when the circuit breaker is closed (green) and the other lit when
the circuit breaker is open (red).
R.
System Module Battery Circuit Breaker
Each system module shall have a battery circuit breaker with shunt
trip. This circuit breaker shall be mounted in a separate NEMA-1
enclosure. When open there shall be no battery voltage present in the
system module enclosure. The system module shall present in the
system module enclosure. The system module shall automatically be
disconnected from the battery by abnormal voltage conditions or when
signaled by other control functions. The system module shall be
provided with a pushbutton to trip this battery circuit breaker from the
module control panel.
S.
System Control Cabinet
The static frequency converter system shall be provided with a free
standing system control cabinet providing monitoring and control of the
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SECTION 16410
415 HZ POWER SYSTEM
complete system. The system control cabinet shall also contain a
main bus to collect the regulated output of each system module.
The system control logic shall be physically barriered and separated
from the power section. The system meters, alarms controls, and
mimic panel shall be located on the control section door. The system
level control fuses shall likewise be located in a separate section
behind a hinged door to minimize electrical shock hazards.
The system control cabinet shall be provided with the following meters
as a minimum:
1.
AC voltmeter with selector switch to monitor the system output.
2.
Output AC ammeter
3.
Frequency (400 - 430 Hz)
All meters shall be 4-1/2 inch square, switchboard type with an
accuracy of at least 2%. A phase selector switch shall be provided for
these meters.
The following system control functions shall be provided as a
minimum:
1.
AC output voltage adjust +/-5%
2.
AC output frequency adjust 400 to 430 Hz
3.
System audible alarm with alarm silence and reset pushbuttons
4.
Emergency shutdown pushbutton with protective cover
The system control cabinet shall be provided with local emergency
shutdown provisions. Activation of the local emergency shutdown shall
cause all module input, output and battery circuit breakers to open,
completely isolating the system from all sources of power. In addition,
the emergency shutdown shall be able to accommodate connection to
the user’s remote emergency shutdown in the computer room.
The system control cabinet shall be provided with automatic over
voltage sensing to protect the computer equipment. Should the output
voltage rise to more than 10% above the nominal voltage, the system
shall automatically cause the voltage to drop and remain below 200
volts and shutdown the system within 0.5 seconds.
The system control cabinet shall be provided with local and remote
output voltage sensing provisions. A local/remote switch shall be
mounted on the cabinet door to allow monitoring of the sensed circuit.
An AC output monitoring plug shall be provided on the cabinet door.
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The system shall be equipped with a 50V DC proportional supply to
provide a readout to the computer equipment. The 50V DC
proportional supply shall be provided with monitor test points mounted
on the system control cabinet door. The local/remote voltage sensing
switch shall also be used to select the input of the 50 Volt proportional
supply. Provide transducer to give 5-20 mA or 1-5V output for future
use.
T.
Storage Battery
A storage battery shall be furnished for the static frequency converter
system with sufficient capacity to maintain system output at the
specified load for 3 minutes. The battery shall provide 100% of the
specified capacity at initial start-up. The battery shall be of heavy duty
industrial type designed for stationary power service.
The battery cell shall be lead-calcium type. The containers shall be
impact resistant plastic of a design proven from field experience. Each
cell shall be equipped with a safety vent.
The specific gravity of the electrolyte shall not be less than 1.210 nor
more than 1.250 at 25C. A float voltage 2.25 volts per cell shall be
used for the lower specified gravity and for the higher specific gravity
the float shall be 2.30 volts per cell. The minimum discharge voltage
shall not be lower than 1.63 volts per cell.
Battery shall be supplied with:
U.
1.
Racks protected with electrolyte resistant paint and designed for
seismic zone 4 installation.
2.
Intercell and invertor connectors for racks, end-to-end and/or
back-to-back.
3.
Hydrometer and thermometer.
4.
Special tools and fittings required to assemble the battery.
5.
Cell numerals.
6.
Layout and assembly instructions and parts lists.
Remote Alarm Panel
A wall mounted NEMA 1 enclosed remote alarm panel shall be
provided and shall include, as a minimum, the following devices:
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1.
System on battery alarm and light.
2.
Low battery alarm and light.
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415 HZ POWER SYSTEM
3.
Output over voltage and light.
4.
Summary alarm for all module malfunctions.
5.
New alarms - A separate alarm for a second summary alarm
condition.
6.
Audible alarm with silence and reset pushbuttons.
7.
Lamp test./reset pushbutton.
All alarm lights shall be long life LED type: incandescent bulbs shall
not be used. An audible alarm shall be activated when any of the
above alarms come on.
V.
Self-Diagnostic Circuitry
The static frequency converter system shall be provided with built-in
diagnostic circuitry for troubleshooting and circuit alignment aids. The
following shall be considered as minimum requirements:
1.
Indication of rectifier in control mode.
2.
Indication of module synchronizing with system load bus.
3.
Indication of positive DC bus ground fault.
4.
Indication of negative DC bus ground fault.
5.
Indication of the degree of overload.
6.
Indication of UNDERVOLTAGE trip for battery circuit breaker.
7.
Indication of UNDERVOLTAGE trip for module input circuit
breaker.
8.
Indication of UNDERVOLTAGE trip for module output circuit
breaker.
W. Line Drop Compensator
One (1) line drop compensator (LDC) shall be provided on the load
side of the system to compensate for the voltage drop due to the
varying distance of the load branch cable length. The LDC shall be
provided as a spare unit to be used in the future for direct connection
of computer equipment to the system equipment. The voltage
compensation shall be accomplished by a capacitor filter tuned to the
inductive line. Active circuits such as SCR’s, transistors or other
semiconductors shall not be used.
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The LDC shall be housed in the system control cabinet or in a LDC
cabinet. Each LDC shall contain:
1.
2.
3.
4.
A branch load circuit breaker.
Voltage adjustment taps.
Overload sensor.
Auxiliary contacts.
The LDC cabinet shall be compatible, electrically and physically, with
the system control cabinet. The LDC cabinet shall be capable of being
attached to the system control cabinet.
The LDC cabinet shall be constructed with electrical barriers so that
individual LDC assemblies can be removed and reinstalled without
shutting down other LDC’s. The branch load circuit breaker’s line side
shall be behind electrical barriers when the LDC assembly is removed.
After the initial adjustment, the LDC shall automatically compensate for
line voltage drops due to any load change. The LDC shall compensate
up to a 20% voltage drop in 4% steps.
The LDC shall be current limited and contain a fast acting solid state
overload sensor. When a fault or a overload occurs in the load branch,
the LDC shall limit the current the system has to supply to the load
branch until the overload sensor can trip the branch circuit breaker
open, minimizing the voltage transients to other branch loads.
Each LDC load branch circuit breaker shall have auxiliary contacts,
one normally open an done normally closed, for monitoring circuit
breaker position by user.
X.
Miscellaneous Requirements
All materials and parts comprising the system shall be new, of current
manufacture, of a high grade and free from all defects and
imperfections and shall not have been in prior service, except as
required during factory testing.
All active electronic devices shall be solid state. All semiconductor
devices shall be hermetically sealed. Vacuum tubes shall not be used
for any purposes. All relays shall be dust tight.
The maximum working voltage, current and di/dt of all solid state
power components and electronic devices shall not exceed 75% of the
ratings established by their manufacturer. The operating temperature
of solid state component cases shall not be greater than 75% of their
ratings. Electrolytic capacitors shall be computer grade and be
operated at no more than 90% of their voltage rating.
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Wiring practices, materials and coding shall be in accordance with the
requirements of the National Electrical Code, and applicable local
codes and standards.
All bolted connections of bus bars, lugs and cables shall be in
accordance with requirements of the National Electrical Code and
other applicable standards. All electrical power connections shall be
torqued to the required value and marked.
The system equipment shall be constructed in NEMA Type 1
enclosures, designed for floor mounting. The system equipment shall
be structurally adequate and have provisions for system bracing,
hoisting, jacking and forklift handling.
The individual cabinets shall be capable of being arranged either
butted side-by-side or butted back-to-back. Wire shall be protected in
a manner which separates power and wiring. Provisions shall be
made in the cabinets to per installation of input, output and intercabinet
cabling, raceway or conduit.
The system cabinet shall be cleaned, primed and painted with the
manufacturer’s standard color.
The system cabinet shall be cleaned, primed and painted with the
manufacturer’s standard color.
Adequate ventilation with dust filter shall be provided to ensure that all
components are operated within their environmental ratings. The
cooling fans shall be redundant. All fans shall be equipped with wind
vane sensors connected to an alarm on the module control panel.
Temperature sensors shall be provided to monitor temperature critical
components. Upon detection of temperatures in of component
manufacturer’s recommended ambient working temperature, the
sensors shall cause audible and visual to be sounded on the module
control. Provide alarm silent reset pusbuttons.
410.03
DESCRIPTION OF MOTOR GENERATOR SET
A.
Operation
The motor generator (MG) set shall convert the utility input power into
mechanical rotation by an AC motor, and convert to 415 Hz, 208 volts,
3-phase, 3-wire output power through an AC generator.
The motor generator and controls shall be capable of satisfactorily
operating at 115% of rated load for 2 hours before protective devices
operate. The MG set shall operate at 100% of rated load continuously
and 200% of full rated load for 1 minute.
16410-rev0
16410 - 16
December 2004
SECTION 16410
415 HZ POWER SYSTEM
Efficiency of the MG set shall be 82% minimum at rated load and 75%
minimum at half load.
The MG set noise level shall not exceed 80 dBA at a distance of 3 feet
from the unit.
Radio frequency interference generated from the MG set shall be
factory suppressed. The MG set shall be so designed as to be
interference free to communications system.
B.
Configuration
1.
The motor generator set shall consist of a motor, generator,
exciter, and voltage regulator with standard controls, protective
devices, instrumentation, paralleling equipment and accessories
as specified herein.
2.
The MG set shall be induction motor, synchronous generator, self
ventilating design for operation at no more than 1800 RPM.
3.
Rotating Equipment: The motor, generator, and exciter shall be
combined on a common shaft of two-bearing construction. The
complete shaft assembly shall be statically and dynamically
balanced. All frame and enclosures shall be vermin proof.
System requiring external cooling fans is not acceptable.
4.
The rotor and bearings shall be capable of safe operation at a
speed of 35% in excess of the generator rated speed.
The rotor body shall be constructed of a solid steel forging of
laminated segments of high grade electrical sheet steel. Each
field pole winding shall be constructed to make a rigid and durable
rotating field assembly.
The rotor coil shall be so constructed as to withstand the
mechanical stresses due to the maximum operating overspeed in
combination with the forces resulting from the maximum excitation
and zero armature current. The field coils shall be so insulated as
to safely withstand voltages which may be impressed upon them
under all operating and emergency conditions. The conditions
shall include the maximum voltages obtainable from the rapid
response excitation system used with the generator, and the
transient voltages obtainable from the rapid response excitation
system used with the generator, and the transient voltages
encountered.
5.
16410-rev0
The MG assembly shall be statically and dynamically balanced in
manufacture to a maximum permissible vibration level of one (1)
mil peak-to-peak.
16410 - 17
December 2004
SECTION 16410
415 HZ POWER SYSTEM
6.
The rotating mass of the MG set shall have sufficient stored inertia
to meet the requirements of regulation and operation as specified.
7.
The motor and generator stators shall be built of high-grade silicon
steel laminations with precision punchings, deburred, and
individually installed.
The stator windings shall be braced to withstand 3-phase short
circuits at their terminals without injury to the stator winding.
8.
The MG bearing shall be heavy duty ball type of degasses steel.
Each bearing shall have a minimum life of 50,000 hours and a
design life of 75,000 hours (minimum) when the unit is operated at
full load and rated temperature.
The bearing housing and closure shall be supplied with a feedthrough greasing system to ensue complete bearing lubrication.
9.
Lifting Attachments: One lifting eye shall be provided on the
motor and one on the generator to support these components
during lifting (horizontally only). The complete motor-generator
shall be designed for lifting and transporting by forklift trucks.
10. Control Cabinet: All controls, indicating lights, protective devices,
and instruments shall be mounted in the control cabinet.
11. Wiring: All wiring shall have ample service loops and be protected
from abrasion. Wiring and wiring harnesses shall be secured at
least every 6 inches. All terminals shall be identified in
accordance with the wiring diagram.
C.
16410-rev0
Motor Characteristics
1.
The AC motor shall be an 1,800 RPM, squirrel-cage induction, self
ventilated, dripless type with windings which are impervious to oil,
solvents, moisture, mild acid and alkalies.
2.
The windings shall be copper, Class F insulation, 100% vacuum
impregnated, rated at 80C rise.
3.
The generator exciter shall be rated at least 2.5 times the normal
operating voltage.
4.
Kilowatt rating shall be as shown on the Drawings.
5.
Output Rating: 208V, 415 Hz, 3-phase, 3-wire.
6.
Power Factor: 80% (lagging).
7.
Voltage Build Up: Initial voltage build up shall be completely
automatic.
16410 - 18
December 2004
SECTION 16410
415 HZ POWER SYSTEM
8.
Voltage Adjustment: The output voltage shall be capable of being
adjusted over a minimum range of plus or minus 100% from rated
voltage.
9.
Voltage Regulation: A generator voltage regulator shall be
provided and installed in the control panelboard. The regulator
shall be a voltage sensing static type with no electrolytic
capacitors or electronic tubes. The regulator shall be equipped
with a control for manual adjustment of the generator voltage level
to +/-10 percent of generator rated voltage. The regulator shall
provide excitation control necessary to maintain the adjusted
generator output voltage over a load of zero to 100% of the
generator capacity at rated frequencies.
10. Voltage Steady State Stability: Steady state voltage stability shall
be plus or minus ½ of one percent at any load from no load to and
including full rated load.
11. Voltage Transient Limits: Upon sudden application or removal of
full rated load at rated power factor, the output voltage shall not
deviate more than plus or minus 15% from the preset value.
12. Voltage Recovery Time: Following instantaneous application or
removal of 50% rated load, the output voltage shall recover to the
regulation band within 0.2 seconds.
13. Phase Voltage Balance: The individual line-to-neutral voltages
shall remain balanced within one percent under all balanced load
conditions. With one-third rated current on any one phase and no
load on the other two, maximum deviation of any phase voltage
from the average the three phase voltages shall not exceed 4%.
14. Modulation: Voltage and frequency modulation shall not exceed
0.5%.
15. Harmonics: The maximum total harmonics shall not exceed 2.0%
when measured line to line and line to neutral. The maximum
single harmonic shall not exceed 1.5% of fundamental at the
steady state voltage.
E.
Paralleling Equipment
The motor generator set shall be capable of being paralleled to and
disconnected from a common bus supported by MG sets having the
same internal impedances, electrical characteristics, same voltage,
and frequency. Provide cross-current compensation method of parallel
operation. Paralleling and disconnecting of generators shall be
possible while the bus in under load and shall share the load within 5%
under all conditions from no-load to full-load at rated power factor.
16410-rev0
16410 - 19
December 2004
SECTION 16410
415 HZ POWER SYSTEM
The MG set shall be equipped with all necessary paralleling equipment
and switchgear with over voltage protection, shunt trip output circuit
breaker and motor positioning controls. The paralleling system shall
provide the necessary termination for the option of remote and local
operation. Control panel lights associated with the paralleling system
shall be push-to-test type.
Manual paralleling shifting controls and synchronization indication shall
be easily accessible to the operator placing two or more units on
output bus.
F.
Control Instrumentation and Protective Devices
1.
Input Circuit Breaker: Input circuit breaker shall be molded case,
thermal magnetic type rated for 600 volts, 60 Hz, 3-phase, 3-wire
and rated not more than 125% of the ultimate system load.
It shall be equipped with a factory installed 24V DC shunt trip with
coil clearing contact and shall provide internal thermal over current
and instantaneous short circuit protection in each pole with a
minimum interrupting capacity of, not less than, 22,000
symmetrical RMS amperes.
It shall be identified with a nameplate.
16410-rev0
2.
Motor Controller: Motor control shall be reduced voltage type,
limiting the starting current to 150% of full load current and shall
be equipped with thermal overload units. Controllers shall
incorporate under voltage and over current protection and motor
inrush current during start-up. Provision shall be made to permit
remote operation.
3.
Start-Stop Pushbutton: Pushbuttons shall be two single
pushbuttons with “STOP” button palm size. “Motor On” light shall
be provided on the front of the control panel.
4.
Control Circuit Transformer: A transformer with fused primary and
secondary shall be provided for operation of control and indicating
devices.
5.
Output Circuit Breakers: Output circuit breakers shall be manually
operated, rated for 600 volts, 415 Hz, 3-phase, 3-wire. It shall be
tripped by overload and short circuit protection with auxiliary shunt
trip capability specifically rated and calibrated for use on 415 Hz
circuits and shall show nameplate information to this effect on the
manufacturer’s name plate.
16410 - 20
December 2004
SECTION 16410
415 HZ POWER SYSTEM
6.
Output UNDERVOLTAGE Protection: The output
UNDERVOLTAGE protection system shall operate the shunt trip
in the output circuit breaker, illuminate a push-to-test fault
indicating light and provide for manual reset. The
UNDERVOLTAGE protection shall operate at no less than 75% of
rated 415 Hz output voltage with very inverse time characteristics.
7.
Output UNDERVOLTAGE Protection: The output
UNDERVOLTAGE protection system shall operate the shunt trip
in the output circuit breaker, illuminate a push-to-test fault
indicating light and provide for manual reset. The
UNDERVOLTAGE protection shall operate with very inverse time
characteristics when the output voltage exceeds 110% of the
rated 415 Hz output voltage, from an average sensing of the three
phase voltages.
8.
Circuit Breaker Shunt Trip Operation: The operator of the shunt
trip devices shall inhibit circuit breaker operation from transient
voltage excursions caused by adding or dropping 100% rated
load.
9.
Load-On Indicating Light: The MG set shall be provided with a
“load-on” push-to-test” light to indicate that the output circuit
breaker is closed and that output power is available.
10. Indicating Meters: Provide voltmeter, ammeter, and frequency
meter (1.0% accuracy) for 415 Hz service. The voltmeter and
ammeter shall each be provided with a phase selector switch
mounted on the control panel for phase monitoring. Ammeter
scale shall read the full load output of the generator in the upper
third of the scale. The voltmeter scale shall provide reading for at
least 10% over-voltage.
11. Elapsed Time Meter: An elapsed time meter with a 99,999-hour,
five digit scale shall be provided on the control panel indicting the
total operating time of the motor-generator set.
G. Alarm and Safety Devices
Each MG set shall have, as a minimum, the following devices, controls
and alarms:
Conditions
1
2
3
4
5
16410-rev0
Low Oil Level
High Winding Temp
Output Breaker
Tripped
Overload (400 Hz)
Fault (400 Hz)
16410 - 21
Alarm
Simultaneous
Control Actions
Annunciated Alarm
Annunciated Alarm
Annunciated Alarm
M-G shut down
Annunciated Alarm
Annunciated Alarm
M-G shut down
M-G shut down
December 2004
SECTION 16410
415 HZ POWER SYSTEM
6
7
8
High Top Bearing
Temp
High Lower Bearing
Temp
Paralleling Failure
Annunciated Alarm
Annunciated Alarm
Annunciated Alarm
Shutdown of the problem M-G set shall automatically bring the next
available M-G set “on-line”.
H.
Environmental Conditions
The motor generator sets shall operate satisfactorily at rated threephase loads under the following conditions:
I.
410.04
16410-rev0
1.
Ambient temperatures ranging from 0 to +40C when operating.
2.
Ambient storage temperature ranging from -25C to +55C.
3.
Relative humidity up to 95 percent.
Miscellaneous Requirements
1.
Nameplates: All controls, instrumentation, and indicator lights
shall be permanently and legibly identified with suitable words,
phrases, or abbreviations thereof to indicate the use or purpose of
the part. The marking may be on the part itself, or on the visible
surface adjacent to the part. Nameplates shall be engraved
plastic laminate or engraved or machine stamped metal.
2.
Identification: A metal nameplate not exceeding 5 inches by 6
inches shall be permanently attached by the manufacture at a
convenient location on the outside of the unit. Nameplate
information shall include manufacturer’s name and code
identification number, required input and output voltage, frequency
and current at full load, output KVA rating and the total weight.
3.
Terminal Blocks: Suitable clearly and permanently labeled
terminal blocks which are readily accessible for qualified
personnel shall be included in each separately mounted unit for all
interconnecting wiring and for the 480 V power supply and 208 V
load connections.
4.
Display: Readily-readable copies of the motor, generator, control
and 415 Hz distribution schematics shall be posted inside the
control panel doors and covered with ¼-inch plexiglass shields.
Manufacturer shall leave ample space for the distribution
schematics to be added in the field.
DESCRIPTION OF 415 HZ DISTRIBUTION EQUIPMENT
16410 - 22
December 2004
SECTION 16410
415 HZ POWER SYSTEM
410.05
A.
Provide distribution equipment including feeders, distribution panels,
branch circuit wiring and computer equipment connections as specified
herein and as shown on the Drawings.
B.
The distribution panels shall be centrally located in the computer room
among the 415 Hz computer equipment and shall be suitable for
operation at 415 Hz. The panels and circuit breakers shall be rated for
240 volts, 415 Hz, 3-phase, 3-wire, and shall be specially calibrated to
respond to available short circuit current at 415 Hz.
C.
Each circuit breaker shall be molded case, bolt-on type with internal
thermal over current and instantaneous short circuit protection in each
pole.
D.
The computer equipment connection shall include a heavy duty, nonfusible type disconnect switch and a water tight special purpose
receptacle to match the computer equipment plug configuration.
E.
Feeder or branch circuit wiring shall be copper conductors with THWN
insulation in rigid aluminum conduits.
INSTALLATION OF STATIC FREQUENCY CONVERTER
A.
The static frequency converter shall be installed in a properly
ventilated, air-conditioned, and acoustically treated room in
accordance with the manufacturer’s recommendations and as shown
on the Drawings. Manufacturer’s field service shall be provided to
place the static frequency converter equipment in operation.
B.
Equipment shall be installed free of moisture and dirt. Interconnection
wiring shall comply with the National Electrical Code and ANSI.
The batteries shall be seismically anchored to the floor with secondary
containment. Bolt connectors shall be stainless steel with electrolyte
resistant coating after making the connections.
C.
16410-rev0
D.
The following procedures, as a minimum, shall be performed by the
manufacturer’s field service engineer during the course of the static
frequency converter system start-up.
E.
Visual Inspection
1.
Visually inspect all equipment for sings of damage and/or foreign
material.
2.
Check all battery cells for proper electrolyte levels.
3.
Observe type of ventilation, room cleanliness, use of proper signs
and any safety related items that may be noteworthy.
4.
Check for proper cell numbering.
16410 - 23
December 2004
SECTION 16410
415 HZ POWER SYSTEM
F.
5.
Check for proper cell interconnections relative to polarity
throughout the battery.
6.
Check all cell tops for cleanliness.
Mechanical Inspection
1.
Check all power connections for tightness.
2.
Check all control wiring terminations and plugs for tightness
and/or proper seating.
3.
Check to see that all subassembly parts are secure.
4.
Check torque on battery cell posts.
G. Electrical Precheck
H.
I.
16410-rev0
1.
Check system for grounds.
2.
Check DC bus for short circuits.
3.
Check input power for proper voltages and phase rotation.
4.
Check and adjust, if necessary, all power supply voltages.
5.
Check all lamp test functions.
Initial Unit Start-Up
1.
Verify that all alarms are in a “go” condition.
2.
Energize unit and verify proper DC start-up, and AC phase on.
3.
Check DC link holding voltage, AC output voltages, and output
waveforms.
4.
Check final DC link voltage and invertor AC output. Adjust if
required.
5.
Check for proper paralleling.
System Protection Settings
1.
Check battery discharge.
2.
Check DC UNDERVOLTAGE warning.
3.
Check DC over voltage and DC UNDERVOLTAGE trip.
4.
Check AC over voltage and AC UNDERVOLTAGE trip.
16410 - 24
December 2004
SECTION 16410
415 HZ POWER SYSTEM
5.
J.
K.
L.
Simulate leg fuse blown.
Batteries
1.
Check all control battery terminations..
2.
Check for proper control of battery.
Waveforms
1.
Check DC line ripple.
2.
Check all leg quasi-square waves.
3.
Check invertor output waveform.
System Check After Load Commitment to the System
1.
Check AC input current.
2.
Check charger output current.
3.
Check DC link voltage.
4.
Check invertor output voltage and waveform.
5.
Check invertor output current,
6.
Check input voltage waveforms.
7.
Verify remote monitor operation.
8.
Simulate utility outages.
9.
Perform 2-minute battery run. Verify no abnormal heating of
battery connections.
10. Verify proper charger current limit setting.
11. Check and record voltage of all cells in the battery. Also check
and record the specific gravity of all sells that have a voltage of
more than 0.04V below the average cell voltage for the entire
battery.
12. Verify selective trip functions.
13. Adjust LDC.
M. Operational Training
16410-rev0
16410 - 25
December 2004
SECTION 16410
415 HZ POWER SYSTEM
Prior to leaving the site, the manufacturer field service engineer shall
familiarize responsible personnel with the operation of the system.
The system equipment shall be available for demonstration of the
operation modes. Training shall be one day minimum.
410.06
410.07
16410-rev0
INSTALLATION OF MOTOR GENERATOR SET
A.
Installation shall conform to the NEC and shall be in strict accordance
with manufacturer’s instructions and as shown on the Drawings.
Manufacturer’s field services shall be provided to place the motor
generator set and making necessary adjustments and start-up to
ensure optimum operation. Motor generator set shall be installed in a
room that is designed to attenuate the noise produced by the set, and
shall be ventilated in accordance to manufacturer’s instruction.
B.
Mount motor generator set on concrete slab. The top of the concrete
slab shall be approximately 4 inches above ½ inch chamfer. The slab
shall be of adequate size to project at least 8 inches beyond the
equipment.
C.
Provide anchor bolts and sleeves for installation of the unit on concrete
foundation. Anchor bolts and sleeves shall be type size, and
metallurgy recommended by the manufacturer of the MG set.
Placement of anchor bolts and sleeves for the motor generator set
shall be in strict accordance with details provided by the manufacturer
of the MG set.
D.
Provide vibration isolators to isolate vibrations from the MG set to the
foundation. Type, number, and arrangement of the isolators shall be
as recommended by the manufacturer of the MG set.
E.
MG set shall be grounded in accordance with the National Electrical
Code.
INSTALLATION OF 415 HZ DISTRIBUTION EQUIPMENT
A.
A 415 Hz distribution panel shall be centrally located in the computer
room among the 415 computer equipment to ensure that the voltage
drop from this distribution panel to any 415 Hz computer equipment
does not exceed 2%.
B.
The feeder from the frequency converting equipment to the 415 Hz
distribution panel shall be sized to limit the voltage drop to 2%
maximum.
C.
Feeder and branch circuit wiring shall be copper conductors with THW
or THWN insulation in aluminum conduits. Steel conduits shall not be
used.
D.
Voltage drop calculations shall be done in accordance with the
following formulas and tables:
16410 - 26
December 2004
SECTION 16410
415 HZ POWER SYSTEM
1.
Effective Resistance
R’ = KR (formula 1) /1/
R’ =
R =
Where:
x
=
Where:
effective resistance in ohms
true resistance with continuous current in
ohms
K = skin effect ratio as determined from Table 1 in
terms of x
0.063598 (fM/R) ½ (Formula 2) /1/
f =
M =
R =
Example:
frequency in cycles per second
magnetic permeability of conductor; M=1 for
copper conductor
DC resistance at operating temperature in
ohms per mile
Determine the resistance of a 250 MCM copper
conductor at 415 Hz
From Table 8 of National Electrical Code (NEC)
R = 0.0515 OHM = 0.0510
MFT
OHM x 5.28
MFT
MFI = 0.2719 OHM
MI
MI
Therefore, x = 0.073598 x (415 Hz x 1/0.2719 OHM) ½ = 2.48
MI
/1/ Donald G. Fink and H. Wayne Beaty - Standard Handbook for
Electrical Engineers, Eleventh Edition, pp. 4-27
From Table 1, K = 1.163
Therefore, R’ = KR = 1.163 x 0.515 OHM = 0.0599 OHM
MFT
MFT
16410-rev0
TABLE 1 SKIN-EFFECT RATIOS
(Bur. Std. Bull. 169, pp. 226-228)
X
K
X
K
0
1
2.9
1.28644
0.1
1
3
1.31809
0.2
1.00001 3.1
1.35102
0.3
1.00004 3.2
1.38504
0.4
1.00013 3.3
1.41999
X
6.6
6.8
7
7.2
7.4
K
2.60313
2.67312
2.74319
2.81334
2.88355
17
18
19
20
21
K
6.26817
6.62129
6.97446
7.32767
7.68091
0.5
0.6
0.7
0.8
7.6
7.8
8
8.2
2.95389
3.02411
3.09445
3.1648
22
23
24
25
8.03418
8.38748
8.74079
9.09412
1.00032
1.00067
1.00124
1.00212
3.4
3.5
3.6
3.7
1.4557
1.49902
1.52879
1.56587
16410 - 27
X
December 2004
SECTION 16410
415 HZ POWER SYSTEM
TABLE 1 SKIN-EFFECT RATIOS
(Bur. Std. Bull. 169, pp. 226-228)
X
K
X
K
X
0.9
1.0034
3.8
1.60314 8.4
K
3.23518
26
K
9.44748
1
1.1
1.2
1.3
1.4
1.00519
1.00758
1.01071
1.0147
1.01969
3.9
4
4.1
4.2
4.3
1.64051
1.67787
1.71516
1.75233
1.78933
8.6
8.8
9
9.2
9.4
3.30557
3.37597
3.44638
3.5168
3.58723
28
30
32
34
36
10.????
10.88888
11.56785
12.27471
12.9816
1.5
1.6
1.7
1.8
1.9
1.02582
1.03323
1.04205
1.0524
1.0644
4.4
4.5
4.6
4.7
4.8
1.82614
1.86275
1.89914
1.93533
1.97131
9.6
9.8
10
10.5
11
3.65766
3.72812
3.79857
3.97477
4.151
38
40
42
44
46
13.68852
14.39545
15.1024
15.80936
16.51634
2
2.1
2.2
2.3
2.4
1.07816
1.09375
1.11126
1.13069
1.15207
4.9
5
5.2
5.4
5.6
2.0071
2.04272
2.11353
2.18389
2.25393
11.5
12
12.5
12
13.5
4.32727
4.50358
4.67993
4.85031
5.03272
48
50
60
70
80
17.22333
17.93032
21.46541
25.00063
28.53593
2.5
2.6
2.7
2.8
1.17538
1.20056
1.22753
1.2562
5.8
6
6.2
6.4
2.3238
2.39359
2.46338
2.53321
14
14.5
15
16
5.20915
5.3856
5.56208
5.915
90
100
32.07127
35.60666
2.
X
Effective Reactance
X
=
2 fL (Formula 3)
f’
L
Where:
=
=
frequency in cycles per second
induction of conductor
Assuming induction of conductor at 60 Hz and 415 Hz is the
same, then
X 415
=
Example:
415 X 60 = 6.917 X 60 (Formula 4)
60
Determine the reactance of a 250 MCM copper
conductor at 415 Hz
In nonmagnetic duct, X 60 = 0.0396 OHM
(from IEEE Std. 241-1983)
MFT
Therefore, X 415 = 6.917 X 60 = 0.274 OHM
MFT
16410-rev0
16410 - 28
December 2004
SECTION 16410
415 HZ POWER SYSTEM
3.
Voltage Drop Calculation
V = 1.732 I (R Cos 0 + X Sin 0) (Formula 5) (from IEEE Std. 1411976)
Where:
V =
I =
R =
X =
O =
Cos O
Sin O
voltage drop in circuit, 3-phase line to line
current flowing in conductor
line resistance for one conductor, in ohms
line reactance for one conductor, in ohms
angle whose cosine is the load power factor
= load power factor, in decimals
= load reactive factor, in decimals
Example:
Determine the voltage drop f a three phase circuit with
250 MCM copper conductors in aluminum conduit,
200 ft. circuit length and 50 amp load at 70 percent
power factor.
From calculations done in 1. and 2. above.
R = 0.0599
OHM
MFT
X = 0.274
OHM
MFT
0 = ARC Cos (0.7) = 45.57C
Sin 0 = 0.71
Therefore,
V =
=
E.
1.732x50x(0.0599x200x0.7+0.274x200x0.71
1000
1000
4.1 volts = 4.1/208 x 100% = 1.97%
Minimum size of feeder or branch circuit conductor shall be 250 MCM
copper. Each circuit shall be provided with an insulated ground
conductor, to be the same size as phase conductors. Table 2 provides
a summary of circuit length calculations based on a 2% maximum
feeder or branch circuit voltage drop and a load power factor of 76.6%
of a typical 415 Hz HGST computer equipment.
Copper
Wire Size
16410-rev0
X
OHM/MFT
R
OHM/MFT
Load
AMP
Conduit
Size
(4) 250 MCM
0.274
0.0599
100
150
200
2-1/2"
(8) 250 MCM
0.137
0.03
100
3-1/2"
16410 - 29
Maximum
Circuit
Length (Feet)
108
72
54
216
December 2004
SECTION 16410
415 HZ POWER SYSTEM
150
200
300
400
410.08
16410-rev0
144
108
72
54
(4) 350 MCM
0.272
0.0477
100
150
200
300
3"
112
75
56
37
(8) 350 MCM
0.136
0.0239
100
150
200
300
400
500
4"
227
151
113
76
57
45
(4) 500 MCM
0.258
0.0386
100
150
200
300
3-1/2"
123
82
61
41
(8) 500 MCM
0.129
0.0193
100
150
200
300
400
500
600
(2) 31/2"
246
164
123
82
61
49
41
SYSTEM TESTING
A.
The 415 Hz power system equipment shall be factory tested in
accordance with the manufacturer’s standard testing procedures. A
test report showing that the equipment has passed the factory tests
and has demonstrated the full output ratings required by this
Specification shall be submitted seven calendar days prior to delivery
of the equipment.
B.
After installation has been completed, the Contractor and the
manufacturer’s field service engineer shall arrange with HGST’s
designated representative to conduct an operating test. All equipment
shall be tested and demonstrated to operate in accordance with the
requirements of this Section and manufacturer’s specifications. One
day operating test shall be conducted under supervision of the
manufacturer’s field service engineer. This test may be witnessed by
HGST’s Engineer at his option.
C.
All circuits shall be tested for continuity. The circuits shall then be
checked to ascertain that it is free of grounds.
D.
Equipment shall also be tested to verify that:
16410 - 30
December 2004
SECTION 16410
415 HZ POWER SYSTEM
1.
System starts up properly and in accordance with the
manufacturer’s start-up procedure.
2.
Paralleling equipment is functioning properly.
3.
Output power is within specified limits.
4.
Output frequency is within specified limits.
5.
Output voltage is within specified limits.
6.
Sound levels are within specified limits.
7.
Metering devices operate as specified.
8.
Warning lights, controls, and alarms operate as specified.
***END OF SECTION 16410***
16410-rev0
16410 - 31
December 2004