Download Single Circuit and Series Wired Applications

Single Circuit and Series Wired
Applications
By Ricky J. Fussell, Electrical Engineer
Surge Suppression Incorporated
At the end of the line in the layered approach to surge suppression are
often high value individual circuits and pieces of equipment. At Surge
Suppression Incorporated we offer a full line of protection for this equipment.
This paper is designed to give you an overview of our products, tell you how
they are applied and show you some applications, and finally to give some
practice applications for you to complete.
Typical Protected Equipment and Circuits
These are the types of circuits and equipment you may need to protect.
•Motors
•Lighting
•Computers and Peripherals
•Industrial Equipment
•Any Individual Piece of Equipment or Circuit
Electrical Environment
Because these circuits are connected to high value equipment they are
generally somewhat protected and have lower voltages and currents. But as
more intelligence is put into devices used in the field there will be more need for
protection in extreme environments.
Typical Voltages and Currents
•Usually 120V or less
•Up to 480V or higher on large machines
•Medium voltage units can protect single machines
•Usually 30A or less
•Large machines can go much higher and require parallel or Kelvin
connections that can go up to hundreds of amps
Exposure Categories
•90% Category A or B
•Some Large Machines Could Be Category C
Sources of Transients
•Internal Sources:
–Load Switching
–Switching Power Supplies
–Motors and Pumps
–Compressors
–Welders
Sources of Transients
•External Sources
–Lightning Strikes to:
•Incoming Power Lines
•Building Structure
–Capacitor Switching
•Can travel deep into structures, especially N-G
–Electromagnetic Pulse (EMP)
•Military Applications
Why not use the cheap way out and just use a L-N MOV?
This example from IEEE Std C62.42-2005 shows why it is not a good idea
to try to just add a L-N MOV on a device to try to save money.
•Example:
Considerations for Series Units
From C62.72-2007 table 4
•A) With regard to the topology of the installation, SPDs are available in two
forms, parallel connected and series connected. Parallel connected SPDs are
widely used and can be installed on nearly any electrical system as the load
current does not pass through the device. In contrast, series connected SPD
can be used for electrical systems with relatively low load currents. Typically,
series connected SPDs are available for systems with load currents up to 3060A, although some devices are available for systems with load currents of 200A
or more.
Solutions
•SSI manufactures 5A, 15A, 30A, and 60A series units.
•All series units are available with terminal or wire connections.
•All series units are available with DRC and other options.
•5A and 15A series units have limited SWT, 30A and 60A units have full SWT.
•Kelvin units are available with currents up to 350A.
•Hardwire units are available for OEM and other applications.
•Parallel units can be used on individual circuits.
•Medium voltage units can be used to protect large pumps and machines.
Considerations for Series Units
From C62.72-2007
•B) If the load current allows, consideration should be given to the choice of a
parallel connected versus a series connected SPD because the connection lead
length of the parallel connected device is variable. …With series connected
SPDs, all lead length for any parallel connected SPD components is internal to
the SPD and fixed in length; therefore, where feasible, series connected SPDs
often offer a benefit of reduced lead length.
•C) If the SPD is to be connected in series with the load to be protected,
consideration must be given to whether the series connected SPD will take the
load offline in the event of an SPD failure. The specifier must understand the
failure mode of the series connected SPD for this situation. Often, it would be
undesirable to remove power to a load in the event of an SPD failure. With
parallel connected SPDs that have proper coordination between the SPD and
any external overcurrent device that may be required as part of the installation
(in series with the SPD but in parallel to the electrical system), the load typically
remains online even with an SPD failure.
Considerations for Series Units
From C62.72-2007
•D) Furthermore, if the SPD is to be connected in series with the load to be
protected, consideration must be given to whether the series connected SPD will
withstand the available short-circuit current of the system that might pass
through the device. For example, if a series connected SPD is installed on a
system with 25000A of available short-circuit current but only has a fault current
withstand capability of 5000A, then the series connected SPD might not
withstand the current flowing through the SPD and produce an undesirable SPD
failure.
Solution
•Always use the recommended fusing for the series unit. For example the
SPT120-30A requires a Single Pole, 30 Amp Circuit Breaker or a 30Amp, Class
RK5 Fuse. Most circuit breakers can interrupt around 10KA and the RK5 fuse
can interrupt 200KA.
SSI Products for Protecting These Circuits
SSI F/SPx Series Units
•5, 15, 30A, 20KA per mode
•AC or DC 5V to 380V
•Single Phase
•Sine Wave Tracking “SPx”
•Threshold Clamping “FPx”
•Wire “F/SP”
•Terminal Strip “F/SPT”
•DRC contacts available
•Optional RJ protection available
SSI F/SPx Polyphase Series Units
•15, 30A, 20KA per mode
•1S1, 3Y1-2, 3D1, 3N1-4
•Sine Wave Tracking “SPx”
•Threshold Clamping “FPx”
•Wire “F/SP”
•Terminal Strip “F/SPT
SSI F/SPx2 Series Units
•3, 5, 15, 20A, 20KA per mode
•AC or DC 5V to 250V
•Single Phase
•Limited Sine Wave Tracking “SPx”
•Threshold Clamping “FPx”
•Wire “F/SP2”
•Terminal Strip “F/SPT2”
SSI 60A Series Units
•60A, 20KA per mode
•AC or DC 5V to 380V
•Single Phase
•Sine Wave Tracking “SPx”
•Threshold Clamping “FPx”
•Wire “F/SP”
•Terminal Strip “F/SPT”
•DRC contacts available
SSI TCDIN Series Units
•12-120V AC or DC
•5A
•DIN Rail mount
•Pluggable connectors
•Note: fuse to 5A for 120V!
SSI Kelvin Units
•Advantage models up to 100KA
•Up to 350A current, 2/0 wire
•Alarm, surge counter, DRC and other options
•E8 option
SSI Hardwire Units
•12V to 250V AC or DC
•2 or 3 wire
•Series or Parallel
•20A Series
•OEM-(number wires)-(P or S)-(voltage)
SSI Tower Light Units
•Multiple 1P series circuits
•120V to 750V
•Designed to protect tower light circuits
•TLP-(circuit type)
SSI F/CDIN Series Units
•International DIN mount unit
•Up to 240VAC 1P, 20A
•Phase level and component level fusing
•Not UL approved
SSI Multiple Module Units
•Custom designed
•Any Data Unit, Series units to 30A
•Units are mounted and partly pre-wired
Examples of Single Circuit and Series Wired Applications
Example: Power Plant
A power plant is a good example of a facility that could use
multiple Series and Single Circuit SPDs. The following excerpt is
from C62.23-1995 and can be applied to many different types of
facilities.
Here are some other examples of facilities and circuits. Can you
think of others?
Hospital
Parking Lot Lighting
Convenience Store
Water Treatment Plant
Irrigation System
Installation examples of SSI products
Several of our Resellers provided pictures of installations they have done
for these types of circuits. Here are a few examples:
Practice Applications
Now that you are familiar with the products SSI offers for single circuit and
series wired applications, here are a few practice applications. Some
may have multiple solutions. Try to find the best solution! The answers
are at the end.
Practice Application 1
•Motor
•1P 240VAC 1½ HP
•10A
•Inside application
•Very tight quarters
Practice Application 2
•Remote Traffic Light Controller
•1P 120VAC
•20-25A
•RJ14 Telecom autodialer output
Practice Application 3
•Variable frequency drive
•50HP, 460NN
•65A
•Indoor application
Practice Application 4
•Gas Pump
•120VAC
•20A
•RJ45 Ethernet Communication
Practice Application 5
•Pump Motor in Rock Mine
•4160VAC Delta
•200A
Practice Application 6
•Pick and Place Machine for PCB Assembly
•120/208 wye
•40A
Practice Application 7
•OEM Application for Drink Machines
•120V 1P
•15A
Practice Application 8
•Automated Checkout and Laser Scanner at large department
store.
•120V, 1P
•15A
•RJ45 Ethernet communication
Practice Application 9
•Water Pump for a large nursery
•15HP
•120/208V Wye
•46A
•Outdoor Application
Practice Application 10
•Control Servos (multiple)
•DIN rail mount (need small footprint)
•48VAC
•1A
Practice Application 11
•New construction in factory
•Multiple Variable Frequency Drives (25 circuits)
•120VAC 1P
•15A
Practice Application 12
•MRI Machine in Hospital
•120/208V Wye
•200A
•Need very tight clamping
Practice Application 13
•Cell Tower Lighting
•1P
•Multiple voltages and circuits
Practice Application 14
•Ball Park Lighting
•480V Delta
•40A
•Multiple circuits plus parking lot lighting
Practice Application 15
•Coal Conveyer Belt Drive for power plant
•50HP
•480V Delta
•65A
•Outside, corrosive environment
Answer Key:
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S-SPT2120-20
S-SPT120-30-RJ
SKLA3N4
S-SPT120-30-RJ
MV803N4160
SPT120-60 or CKLA3Y1
OEM-3W-P-120V
SPT120-30A-RJ
SKLA3Y1CD3
S-TCDIN48-6
MMU with FSPT120-30
CDLA3Y1E8
TLP-(circuit type)
RES3N4
SMLA3N4D3