3 Phases to 2 phases.
3 Phases to 2 phases.
(OP)
I've assembled a 3 phase motor starter for a 1/2hp pump that was, "going to be 3 phase", but is now "going to be single phase".
It's a small contactor with electronic overloads. I don't really want to rip these out (it's all 2x) since next week it will probably relapse to, "it's going to be 3 phase", again.
The contactors are more than adequate for the current change.
Does anyone see a problem with just running the second phase back thru the third phase so the electronic overloads remain happy and the system remains three phaseable?
It's a small contactor with electronic overloads. I don't really want to rip these out (it's all 2x) since next week it will probably relapse to, "it's going to be 3 phase", again.
The contactors are more than adequate for the current change.
Does anyone see a problem with just running the second phase back thru the third phase so the electronic overloads remain happy and the system remains three phaseable?
Keith Cress
kcress - http://www.flaminsystems.com





RE: 3 Phases to 2 phases.
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RE: 3 Phases to 2 phases.
Bill
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RE: 3 Phases to 2 phases.
RE: 3 Phases to 2 phases.
Bottom of first page:
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Thanks for the confirmation everyone.
Keith Cress
kcress - http://www.flaminsystems.com
RE: 3 Phases to 2 phases.
You'll be lucky if one selected for three phase current will turn up enough to cover the equivalent single phase current
RE: 3 Phases to 2 phases.
What happens if you left a phase with no current... unbalance trip? (and the unbalance based on magnitude, not considering phase angle?)
=====================================
(2B)+(2B)' ?
RE: 3 Phases to 2 phases.
Differential
Phase loss
and
Overcurrent.
It doesn't really say "electronic" does it..
I don't expect it to cover the entire range with just one model.
Funny thing.. Today they said, "Ah, I think we're going to stick with three phase."
This was after they'd decided 120V single phase on Thursday.
EP that's what the discussion on running one phase back thru the third set was about.
What exactly do they mean about Differential?
Keith Cress
kcress - http://www.flaminsystems.com
RE: 3 Phases to 2 phases.
As others have mentioned, on single phase motors the trick is to loop a current path back and put it through the overload again so you end up with each pole carrying the same current.
RE: 3 Phases to 2 phases.
The story would be different if you had used an electronic LS overload. They monitor for phase order and phase loss and they look for more than simply having current in each phase.