Product Description
Power Transfer Switches for
Limited Service Controllers
Description—Firetrol® Power Transfer Switches are
available completely assembled with Firetrol Limited
Service Controllers. The power transfer switches are
built in two versions:
FTA975 — For use when the normal power source
is a utility and the emergency power source is a
generator set.
FTA976 — For use when both the normal and emergency power sources are utilities.
The entire package of power transfer switch and
controller is completely factory assembled, wired,
tested and shipped as a complete unit for easy field
connection to the power sources and the fire pump
motor.
Approvals—Firetrol power transfer switches are
listed by Underwriters’ Laboratories, Inc., in accordance with UL218, Standard for Fire Pump Controllers; UL1008, Automatic Transfer Switches; UL508,
Industrial Control Equipment and CSA, Standard
for Industrial Control Equipmentl. They are built to
meet or exceed the requirements of the approving
authorities as well as NEMA and the latest editions
of NFPA 20, Installation of Centrifugal Fire Pumps,
and NFPA 70, National Electrical Code.
• FTA975
FTA976
Standard Features—The following are included as
standard with each transfer switch:
„ Emergency power source disconnect switch sized
for connected motor horsepower and voltage
„ (FTA975 only) molded case isolating switch
„ (FTA976 only) thermal-magnetic circuit breaker
„ 3-pole, double throw transfer switch mechanism,
electrically operated, mechanically held
„ Control module providing for the following:
Differential voltage sensing on all phases of the
normal power source
Voltage sensing of the emergency power
source
Frequency sensing of the emergency power
source
Transfer time delay to compensate for momentary
power outages of the normal source
Retransfer from emergency to normal source
is automatically delayed unless the emergency
source fails
Cool-down timer for unloaded running of the
generator set after retransfer to the normal power
source
Instantaneous retransfer to normal if the emergency source fails and the normal source is available
3 second transfer restart delay to reduce current
surges when transferring to or from the emergency source
NO and NC engine control contacts to start the
generator set when the normal power source
fails
„ Transfer Switch Normal Pilot Light
„ Transfer Switch Emergency Pilot Light
„ Emergency Isolating Switch Open Pilot Light
„ Test Selector Switch
„ Transfer By-pass Switch
„ Silence Alarm Pushbutton
„ Emergency Isolating Switch Open and Transfer
Switch in Emergency Audible Alarms
„ Output contacts (NO and NC) for Generator Start,
Emergency Isolating Switch Open and Transfer
Switch position indicators
„ Standard Withstand Rating, emergency side
only
FTA975 (Generator set equipped with molded
case circuit breaker)
3-30HP, 200-600V, 10,000 Amps, RMS Sym.
FTA976
3-20HP, 200-240V, 10,000 Amps, RMS Sym.
25-30HP, 200-240V, 18,000 Amps, RMS Sym.
3-30HP, 380-600V, 14,000 Amps, RMS Sym.
„ NEMA Type 2 (IEC IP11) enclosure
Note: The withstand rating of the normal power
source side of the transfer switch will be the same
as the withstand rating of the fire pump controller
assembled with the power transfer switch.
Options—The following are available as options to
FTA976 Power Transfer Switches:
Special Enclosures
-T NEMA Type 3R (IEC IP14)
-E NEMA Type 4 (IEC IP56)
-F NEMA Type 4X (#304 Stainless Steel) (IEC
IP56)
-G NEMA Type 12 (IEC IP52)
Special paint color or finish - Consult Factory
Circuit Breaker Option
-B Intermediate withstand rating
200-480V - 65,000 Amps, RMS Sym.
550-600V - 18,000 Amps, RMS Sym.
Modifications—The following are available as
modifications to all transfer switches:
Anti-condensation Space Heaters
-H 120 Volt space heater
-J 120 Volt space heater with thermostat
-K 120 Volt space heater with humidistat
-L 240 Volt space heater
-M 240 Volt space heater with thermostat
-N 240 Volt space heater with humidistat
Explanation of Catalog Number
FTA975-BL100B-ED
Type
975 Gen Set
976 Second Utility
208
Start Option
-B Automatic
Withstand rating
-A Standard (FTA976)
-B Intermediate (FTA976)
-D Standard (FTA975)
Modifications
Voltage
-H 200-A 220-240
-F 380-415
-B 440-480
-C 550-600
Ampere rating
100
Example—FTA975-BD100B-ED
FTA975 Power Transfer Switch for generator set
emergency power source, 100 Amp, 440-480 Volts,
with load shed circuits.
Note—Due to continual product enhancements,
dimensions and specifications may change at any
time without notice. Contact the factory or local representative for current specifications.
Alarms
-BX Contacts for remote indication, second utility
source phase failure/phase reversal (FTA976
only)
Miscellaneous
-ED Load shed circuits
-TM Microprocessor type (Group 5) control module
-TN As above, with serial communications port
-S Tropicalization
(919) 460-5200 • www.firetrol.com • Sales Office: Cary, NC 27518 USA
PD975-01(12-15-08)
©ASCO 2008