Download 262923 16484

Luke AFB Master 48 CSI DIVISIONS
6/09
SECTION 262923 16484
VARIABLE FREQUENCY DRIVES
PART 1 GENERAL
1.01
SUMMARY
A. Section Includes: Variable Frequency Drives for speed control and soft
starting of AC Motors.
1.02
SUBMITTALS
A. Product Data: Submit manufacturer’s data for variable frequency
controllers indicating Manufacturers specifications.
B. Shop Drawings: Submit shop drawings showing equipment dimensions and
clearances. Show spatial relationship to adjacent equipment and
structures.
1.03
REGULATORY REQUIREMENTS
A. U.L. (Underwriters Laboratories)
B. F.C.C. Part 15, Class A
C. IEEE 519 - 3% THD for any electrically noise sensitive applications.
1.04
START-UP
A. Include in the price of the equipment, as separate line item, a factory
coordinated start-up service for each VFD.
PART 2 PRODUCTS
2.01
ACCEPTABLE MANUFACTURERS
A. Asea Brown Boveri
B. Danfoss-Graham
C. Emerson
262923 16484
Luke AFB Master 48 CSI DIVISIONS
2.02
6/09
ADJUSTABLE FREQUENCY CONTROLLERS
A. The adjustable frequency controller shall convert 480v, +10% Voltage +5% Frequency, three phase, 60 Hertz utility power to adjustable
voltage/ frequency, three phase, AC power for step-less motor speed
control with a capability of 10:1 speed range. All general options and
modifications shall mount within the standard adjustable frequency
controller enclosure unless otherwise specified.
B. The 1 through 25HP, 480VAC, adjustable speed drive shall be a pulsewidth-modulated (PWM) design that has a carrier frequency of 12KHz or
higher with output line reactor. Six-step PWM with carrier frequency
below 12 KHz shall produce acoustical noise no higher than across-theline motor operation +2dB.
The adjustable speed drive shall generate a sine-coded, adjustable
voltage/frequency three-phase output for complete speed control of any
NEMA B variable speed duty squirrel cage induction motor. The
adjustable speed drive shall maintain a 110% current overload capability
for 60 seconds with automatic stall prevention and voltage boost to
prevent nuisance tripping during load or line side transient conditions.
The adjustable speed drive shall maintain a power factor of not less
than 0.95 throughout its speed range.
C. Drives and motors shall be of size, capacity and quantity as shown on
the drawings.
D. The controller shall produce an adjustable AC voltage/frequency output.
E. The controller
Output current
current rating
speed shall be
meet or exceed
shall have a continuous output current rating of 100%.
capability shall be 1.1 x connected motor full load
for 60 seconds. Average efficiency at full load and full
not less than 97%; efficiency. Minimum FLA rating must
NEC Table 430-150.
F. The adjustable speed drive shall be subject to the following parameters
and tests:
1.
All integrated circuits (TTL) and all components used for circuit
board contribution shall be tested to an acceptance criteria of
0.5% AQL (Accepted Quality Level).
2.
In-circuit testing of all printed circuit boards shall be
conducted to insure proper mounting and correct value of all
components.
3.
Final printed circuit board assemblies shall be functionally
tested via computerized test equipment where all tests and
acceptance criteria are pre-programmed and test results are stored
as detailed quality assurance data.
4.
All fully assembled controls shall be combine-tested for
performance and functionality at the manufacturer’s factory with
fully loaded induction motor(s). The combined test data shall
then be analyzed to insure adherence to quality assurance
specifications.
G. The variable frequency drive (VFD) manufacturer shall have a local
factory-authorized service center. The staff of service engineers at
these locations shall be trained and certified by the VFD manufacturer.
H. The local service center shall provide as a minimum the following
services:
262923 16484
Luke AFB Master 48 CSI DIVISIONS
1.
2.
3.
4.
5.
6/09
Factory coordinated start-up service.
Emergency service calls for one year after start-up.
Six months after start-up, provide a one-day site visit for
inspection of drives and accessories.
Training of customer personnel in basic troubleshooting.
Training shall be on site and shall be a minimum of one day’s
duration and shall be performed in addition to startup of system.
I. All VFD components shall be factory-mounted and wired on a dead front,
grounded, free-standing or wall-mounted NEMA 1 enclosure arranged for a
top or bottom conduit entry. The free-standing enclosure shall be
suitable for mounting on a wall and have inlet air filters.
J. The adjustable speed drive shall have the following basic design:
1.
Bypass-off-auto selector switch (door mounted).
2.
Manual speed potentiometer (door mounted).
3.
Adjustable linear acceleration and deceleration.
4.
Minimum 10:1 (6-60 Hz) controlled speed range capability.
5.
Auxiliary Form C contacts for remote indication of controller
fault condition.
6.
Auxiliary Form C contacts for remote run indication.
7.
Pre-engineered options will be furnished in a standard NEMA 1
enclosure.
8.
Drive to accept a N.C. contact to safely shut down VFD and drive
on by-pass mode.
K. The adjustable speed drive shall be provided with the following
features:
1.
Manual Contactor Bypass with Transfer Switch - The inverter
manufacturer shall provide all components and circuitry necessary
for a complete manual bypass package which shall include:
a.
A three-position switch to safety transfer the motor from
the line, or from the line to the drive at zero speed.
b.
The circuit breaker shall be a door interlocked main power
input disconnect providing positive shutdown of all input
power to the drive VFD shall have a maintenance by-pass
switch. Motor protection and other safety devices shall be
operative in both bypass and drive modes.
c.
The complete package shall be mounted in the enclosure or
directly below and attached to the drive.
2.
Controllers are to be provided with an input line reactor rated
for the amperage of the VFD in the Nema 1 enclosure on the primary
side of each VFD to protect the electrical system from unwanted
high frequency voltage harmonics (500 Hertz).
3.
Output thermal motor overloads.
4.
Door-mounted volt, amp % speed, % load, frequency meters. Provide
auxiliary output terminals on Ammeter for readout and monitoring
by the HVAC Control System, 0-10 VDC for monitoring volt, amps or
frequency.
5.
Output contactor.
6.
Auxiliary contact relay with 2 N.O. and 2 N.C. contacts. See J5 &
J6 above.
7.
Plug-in tester card or prewired fault indication on digital motor.
8.
Catch a Spinning Load: Upon energization, the VFD shall match the
speed of the spinning motor, take control and provide desired
speed.
L. The controller shall include the following protective circuits and
features:
262923 16484
Luke AFB Master 48 CSI DIVISIONS
1.
2.
3.
4.
5.
6.
7.
8.
9.
6/09
Single-phase fault or 3-phase short circuit on VFD output
terminals without damage to any power component.
Static instantaneous over-current and over-voltage trip.
Static over-speed (over-frequency) protection.
Phase sequence detector, line or fuse loss, and under-voltage
protection.
Power unit over-temperature protection.
Motor inverse time overload protection.
Current limit adjustable 50% - 100%.
Current limited stall prevention during acceleration,
deceleration, and run conditions.
Automatic restart after momentary power loss or momentary overvoltage, under-voltage, or over-current due to acceleration rate
set too fast, because other faults, such as an over-current due to
a blown transistor or a short circuit on the output, could cause
damage to the inverter. No restart into ground fault.
M. Fault indicators shall indicate the following fault conditions and shall
be displayed on the front panel of the inverter. When a fault occurs,
the drive shall have built-in diagnostic functions that assist in
determining the cause and source of the fault.
1.
Over-current while running (OC)
2.
Over-current on output (OCL)
3.
Internal short circuit (OCA)
4.
Overload (OL)
5.
Over-voltage while deceleration (OV)
6.
Over-voltage due to power surge (OV)
7.
Over temperature (OT)
8.
Control function error (NULL) - Not on Graham
9.
Ground Fault (GF)
10.
External Fault (EXT)
N. DC bus discharge indicator. The drive must have a visual indication
that is visible with the door either opened or closed as to whether
hazardous voltage still remains on the DC bus so servicing technicians
may avoid exposing themselves to dangerously high voltage.
1.
Current limiting DC bus fuse. - On electrical protection.
2.
Isolated operator controls.
3.
Phase-to-phase short circuit protection.
4.
Over temperature protection.
5.
The adjustable speed drive shall have the following adjustments
available.
a.
Accelerating - 0.1 to 280 seconds.
b.
Deceleration - 0.1 to 280 seconds.
c.
Volts/Hertz adjustments.
d.
Minimum frequency (5 to 100% speed)
e.
Maximum frequency (25 to 150% speed).
f.
Carrier frequency adjusted automatically. (For drives
having a Carrier Frequency of 12 KHz).
g.
Bias and gain adjustments for 4-20mA, 0-5VDC, 0-10VDC
follower.
h.
Calibration adjustment for remote speed indicator (provided
by others)
O. The adjustable speed drive shall be designed to operate within the
following environmental and service conditions.
1.
Ambient service temperature: 10o C to 40o C.
2.
Ambient storage temperature: 20o C to 55o C.
3.
Humidity: non-condensing to 90%.
262923 16484
Luke AFB Master 48 CSI DIVISIONS
4.
5.
6.
7.
6/09
Altitude to 3,300 feet.
Service factor: 1.0.
Input voltage: three phase, 208/240VAC-/-10% for 230VAC series.
Input frequency: 50/60-Hertz +/- 3%.
P. VFD Controller operation:
1.
Selector Switch in the “Off” position: The VFD run circuit will
be open and the system will not operate.
2.
Selector Switch in the “Hand” position: The speeds of the fans
will be controlled by the manual speed potentiometer.
3.
Selector Switch in the “Auto” position: Operation will be from
the input signal with the output speed being proportional to that
signal. Drive will start and stop in response to a contact input
from Building Automation System.
PART 3 - EXECUTION
3.01
INSTALLATION
A. Make electrical connections in accordance with Division 16 requirements
of these specifications.
B. Install the VFD as per the drawings, the manufacturers recommendations
and the NEC.
C. The control scheme shall be adapted so that when the manual bypass
switch is transferred to the magnetic contactor mode, all external
safety devices are also transferred to the holding coil circuit of the
contactor.
D. The VFD technician shall coordinate drive spread control signals to the
drive PC so that 0-100% ramping is achieved under all conditions. In
addition, the ramp (linear) is to be adjusted so that a permanent
minimum low speed equal to 40%, (24 Hertz) is achieved regardless of
control input signals.
E. The mechanical contractor shall coordinate both line and load power
wiring requirements and grounding requirements with the installing
electrical contractor. Power and control conductors shall not be routed
near the control boards, devices subject to noise or induction or the
main PC board.
END OF SECTION
262923 16484