Motor starter A1 and A2 coil contacts

[Jbutts1]

Does it matter which part of the coil power is supplied? (can you reverse polarity)? For example can I put the “hot” current carrying conductor on terminal A2 and leave with a grounded conductor from terminal A1 (assuming power supplieD is 120v.) (what about 24V?) Is there a specific type of load this can or cannot be done with (resistive, inductive, etc) and what are some real life applications of those types of loads. As this is multiple questions in one thread, I hope to receive a lot of really good answers. Thanks in advance!

-jason
Maintenance Electrician/plc tech
Kellogg Co

 

[westward10]

If the coil terminals are A1 and A2 then polarity is not important whether ac or dc. Some dc coils may be + and - in which case it is polarity biased.

 

[Jbutts1]

If the coil terminals are A1 and A2 then polarity is not important whether ac or dc. Some dc coils may be + and - in which case it is polarity biased.

Are there any type of loads that could potentially cause problems if polarity is reversed In an ac system? I.e. low/high pressure switches

 

[Marvo]

Most AC loads will run fine if supply polarity is reversed but some loads are polarity critical. That said, you should always follow the manufacturers wiring diagram.

 

[rapparee]

Are there any type of loads that could potentially cause problems if polarity is reversed In an ac system? I.e. low/high pressure switches

The pressure switches are they passive or active?

You could get mixed up with pnp and npn sensors and switches.

 

[Jbutts1]

Most AC loads will run fine if supply polarity is reversed but some loads are polarity critical. That said, you should always follow the manufacturers wiring diagram.

What are examples of polarity critical loads?
[automerge]1583963119[/automerge]

The pressure switches are they passive or active?

You could get mixed up with pnp and npn sensors and switches.

What happens in either case?