Transformer Selection Chart
Voltage Transformers
Transformers help you to adapt supplied voltages to usable power levels. In control systems, transformers are used to adapt supply voltages to match the needs of the devices employed, and to provide isolation of circuits.
Select the voltage amps that reflect the anticipated load on the circuit, then, select the correct primary and secondary voltage for your application. As always, if you need help selecting the correct transformer for your application calls us at 800-227-9800. We are here to help you.
Control Transformer Selection Chart


For your convenience, we have gathered a variety of sizes and voltages to power your control systems into one selection chart arranged by power capacity (VA ratings). Some larger models have to be ordered. Please ask.
PLANNING TO UPGRADE TO AUTOMATION?
NECC has the finest technical support to help you easily migrate to Digital (DDC) controls. We can help you with your project with engineering, wiring diagrams and panel fabrication.
–or–
If you need onsite help, we can come out and do a survey for you or recommend a local authorized contractor. Together, we can do it. Let us know how we can help you.
Johnon Controls Tamper-Resistant 24V Transformers
The Y65 Series Transformers have a 1/2'' threaded mount on one side. All the low and line volt wiring goes through the mounting spud. The AE-207-120 is a 4'' x 4'' plate mount version. No exposed screw terminals to be messed with!
Emergency Plug-In Transformer
Instant 24V For Emergency or Testing!
Always have a 24V source available. Keep one of these handy dudes in your toolbox. Better yet, connect about 12 to 18'' of stranded wire to it and crimp some alligator clips on the business end.
- Power: 120 Vac
- VA: 50
- Mount: Multi-mount
Honeywell Universal Replacement Transformer
This One Has It All!
It costs a coupla bucks more, but when you’re stuck, you’ll be really glad you have one handy. Multivolt and Multimount—foot, 2''x2'', 3''x3'', 2''x4'', plate surface, panel or knockout mounting.
Transformers With Built-In Circuit Breakers
They cost a little more, but way cheaper than the labor of replacing a burned-out one.