Transformers supply and expand power for fire alarm control panels and notification circuits. The common case is a NAC power expansion transformer that raises the available notification current when a panel's built-in supply cannot carry all the horns and strobes on a circuit.
Size by the total notification load, not by device count — candela setting drives strobe current, so two apparently identical devices can draw very different amounts. Confirm the primary voltage available at the panel location (120V or 240V) and that the unit is listed for fire alarm service.

Silent Knight
Silent Knight 115061 Transformer, Power, 12036VAC, 85VA, 6LEAD
Sale price$48.05
Regular price$57.66
Not in stock - available on backorder - lead time on request
Fire-Lite
Fire-Lite XRM-24BE Optional Transformer
Sale price$139.35
Regular price$167.22
6 units in stock
Fire-Lite
Fire-Lite XRM-24 Transformer, Expands NAC Circuit Power from 3 to 5 Amps, Flex 404 Only
Sale price$166.90
Regular price$200.28
19 units in stock
Resideo
Resideo RA889A1001 120V, 60 Hz Switching Relay with SPDT switching, RA889A1001
Sale price$87.50
Regular price$105.00
Not in stock - available on backorder - lead time on request
Fire-Lite
Fire-Lite XRM-24B Optional Transformer for Fire Alarm Control Panels, 24 Volt 100VA, 120 VAC 60 Hz Input
Sale price$181.40
Regular price$217.68
Not in stock - available on backorder - lead time on request
Simplex
Simplex 478-332 Transformer 120V 60Hz
Sale price$85.05
Regular price$102.06
13 units in stock
Simplex
Simplex 4081-9308 Battery Cabinet with Charger, 220/230/240 VAC Multi-Tapped Input
Sale price$2,904.00
Regular price$3,484.80
12 units in stock
HyperSpike
HyperSpike 90179A-801 70V Constantvoltage Transformer
Sale price$1,441.35
Regular price$1,729.62
2 units in stock
Resideo
Resideo RT850T-240 Solid State Relay with 24-240V Built-in Transformer
Sale price$113.95
Regular price$136.74
Not in stock - available on backorder - lead time on request
Resideo
Resideo RC840T-240 240v Relay w/ Built In 24V Transformer
Sale price$92.60
Regular price$111.12
Not in stock - available on backorder - lead time on request
Resideo
Resideo RC840T-120 120v Relay w/ Built In 24V Transformer
Sale price$74.00
Regular price$88.80
Not in stock - available on backorder - lead time on request
Resideo
Resideo RC840 Electric Heating Relay (w/o Transformer)
Sale price$61.75
Regular price$74.10
Not in stock - available on backorder - lead time on request
Resideo
Resideo RA832A1066 2 Zone 120V Switching Relay w/ DPST Switching, RA832A1066
Sale price$119.95
Regular price$143.94
Not in stock - available on backorder - lead time on request
Resideo
Resideo R8845U1003 Universal Switching Relay w/ Internal Transformer, R8845U1003
Sale price$93.95
Regular price$112.74
Not in stock - available on backorder - lead time on request
Resideo
Resideo R845A1030 Switching Relay w/ Internal Transformer DPST Line Voltage Relays, R845A1030
Sale price$118.25
Regular price$141.90
Not in stock - available on backorder - lead time on request
Resideo
Resideo R8285D5001 50 VA Fan Center w/ DPST Switch Includes R8222U, R8285D5001
Sale price$64.10
Regular price$76.92
Not in stock - available on backorder - lead time on request
Resideo
Resideo R8184M1051 Protectorelay Oil Burner Control with 45 seconds Lock Out Timing, R8184M1051
Sale price$241.85
Regular price$290.22
Not in stock - available on backorder - lead time on request
Resideo
Resideo L8148E1299 High Limit Vertical Mount Aquastat Relay, 15-Degree(F) differential w/ 50VA Transformer, L8148E1299
Sale price$357.10
Regular price$428.52
Not in stock - available on backorder - lead time on request
Resideo
Resideo HZ311K TrueZONE Kit with DATS, Transformer and HZ311 Panel
Sale price$218.45
Regular price$262.14
Not in stock - available on backorder - lead time on request
Resideo
Resideo HZ221K TrueZONE Kit with DATS, Transformer and HZ221 Panel
Sale price$229.30
Regular price$275.16
Not in stock - available on backorder - lead time on request
Resideo
Resideo AT87A1106 Foot/Plate Mounted 120/208/240 Vac Transformer w/ 13" Lead Wires, Built in Protection & Primary Winding Burnout, AT87A1106
Sale price$63.40
Regular price$76.08
Not in stock - available on backorder - lead time on request
Resideo
Resideo AT72D1683 Foot Mounted, Plate Mounted, or Clamp Mounted 120 Vac Transformer w/ 9 in. Lead Wires (40VA), AT72D1683
Sale price$47.75
Regular price$57.30
Not in stock - available on backorder - lead time on request
Resideo
Resideo AT175F1023 Plate or Panel Mounted 120/208/240 Vac Transformer with 9 in. Lead Wires and Metal End Bells, AT175F1023
Sale price$90.35
Regular price$108.42
Not in stock - available on backorder - lead time on request
Resideo
Resideo AT140B1214 Foot Mounted 120/208/240 Vac Transformer with 9 in. Lead Wires and Plastic End Caps, AT140B1214
Sale price$20.20
Regular price$24.24
Not in stock - available on backorder - lead time on request