Cold Fusion
Senior Member
- Location
- way north
For the last 40 years that I have been looking at motor control ckts they have been about the same. The OL contact is on the neutral side of the coil. The hot side of the coil is fed by a 3W/4W S/S, maybe with a local HOA, and maybe with a parallel PLC contact (last 25 years).
Just recently, I had someone tell me that when using an AB E3+, one should wire in an E3+ output contact to control the hot side of the coil. This was necessary to make sure the E3+ could de-energize the coil even if the trip contact welded shut or the neutral side of the coil went to ground. And this was part of "new code".
I've seen the ATEX specification for explosion proof areas, but this application is in ordinary areas.
If so, this makes using an HOA switch a bit more difficult - especially if the E3+ is not network controlled.
All this is quite doable, so that is not my topic.
Does anyone know about "new codes" that would require this?
I'm looking, but would appreciate any ideas on where.
cf
Just recently, I had someone tell me that when using an AB E3+, one should wire in an E3+ output contact to control the hot side of the coil. This was necessary to make sure the E3+ could de-energize the coil even if the trip contact welded shut or the neutral side of the coil went to ground. And this was part of "new code".
I've seen the ATEX specification for explosion proof areas, but this application is in ordinary areas.
If so, this makes using an HOA switch a bit more difficult - especially if the E3+ is not network controlled.
All this is quite doable, so that is not my topic.
Does anyone know about "new codes" that would require this?
I'm looking, but would appreciate any ideas on where.
cf