Graham 1703 AFD Control Power

[Billgas]

Perhaps this AFD model number is a blast fom the past for a few of you folks. Here are my wonderings...

Can control power and drive power come from separatly derived (ie: out of phase) power sources?

 

[ozmosis]

I'm not too familiar with the Graham 1703 but as it's an old drive they would typically have a separate transformer that fed the control board. Depending on the AC supply usually depends on the control tapping. These transformers would typically link across from the main incoming to the AFD rectifier so yes, it is possible to have a separate power source to the control board. As it would be converted to DC it wouldn't matter on the phase rotation.

 

[Billgas]

Yes, it did have a control transformer. We had many unexplained shutdowns, and chose to feed the control wiring from a UPS. The UPS sometimes does not stay phase locked to the main source. The main source is a natural gas generator.

 

[jraef]

So it was giving you problems and you want to know if you can try this, or you tried it and it worked but you want to know if it will be a future problem?

JRaef.com
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