View Full Version : Basic coil on a contactor

13-02-2014, 08:09 AM

I'm new'ish to the trade but am fully qualified in AC and Refrigeration the only aspect of the trade that I'm still learning about is the electrical side of certain things.

Please see attached photo!

It's from a Toshiba 3 pipe super multi.

It's off at the minute under an Ad alarm. Basically Ad relates to 3 things which it could be. 1- HP 2- O/L on contactor 3- over heat of compressor.

It's not 2 as I've checked.

My question is -11181 on the coil of the contactor A1/A2 which way does the current flow to power the coil? Does it flow up through A2 first, then through the loop (yellow) or up through 95 and through A1 first?

Thank you for any help

13-02-2014, 02:45 PM
Power is coming from terminal L2 and supplies voltage to the pink wire that is connect to A1. Current flows through A1 and A2 is being use as the common point.

13-02-2014, 07:47 PM
I think it's worth mentioning that ergonomically & logically you would expect power to 'follow the numbers', as contractor coils are not polarity sensitive, you often find they have been wired from A2 to A1. Please don't assume that because this machine is A1-A2, all machines & switch boards are.
Apologies if you're now rolling your eyes & shouting "I knew that!" at your screen. ;)

install monkey
13-02-2014, 07:49 PM
terminal 95,96 is a switch that will open circuit the contactor coil in an overload condition- preferably run though it with a1 wiring (live to coil) as opposed to using a2- neutral

25-02-2014, 11:47 AM
Great collection of information, thanks for sharing it.