Baptistry re-visited

[ceb58]

OK, got the equipment in for the heater/pump that I am doing. It came with a 24v transformer, 240v 50amp rated 24v contactor,a fill valve and high water sensor both 24v. No problem schematic is very clear. My only concern is the MFG. instruction state that it is to be supplied with a 240v 2 pole GFCI breaker, (that's a no brainer). But what is concerning me is the schematic shows to power the heater, 240v 6kw, from the contactor. It then shows to pick up one leg from the contactor to supply the pump, 120v. In my mind I am wondering if the GFCI breaker will cause problems because it will "see" an unbalance in the phases?

 

[Twoskinsoneman]

OK, got the equipment in for the heater/pump that I am doing. It came with a 24v transformer, 240v 50amp rated 24v contactor,a fill valve and high water sensor both 24v. No problem schematic is very clear. My only concern is the MFG. instruction state that it is to be supplied with a 240v 2 pole GFCI breaker, (that's a no brainer). But what is concerning me is the schematic shows to power the heater, 240v 6kw, from the contactor. It then shows to pick up one leg from the contactor to supply the pump, 120v. In my mind I am wondering if the GFCI breaker will cause problems because it will "see" an unbalance in the phases?

You are right. At first glance it seems like any current on the 120v circuit will pop it.

 

[Sharpie]

I don't believe you will have a problem as long as the 120V is using the grounded (neutral) that goes through the 2-pole GFCI. All of the wires go through the same CT. When the current is going out on one leg, and back in on another, they cancel each other out. And that goes for the current on the 120V as well.
The only time you should have a problem is if there really is a ground fault.

I know that might be a little confusing. Ask more questions if that muddies the water.

 

[Twoskinsoneman]

I didn't realize 2-pole 240v GFCI had a place for neutral. I thought it just had a connection to the neutral bus for the internal electronics. I have heard of 120/240 GFIs that had a neutral for the bus and one for 120 circuits but I haven't used one.

But I agree if the cb has a place for load neutral should have no problems

 

[ceb58]

I don't believe you will have a problem as long as the 120V is using the grounded (neutral) that goes through the 2-pole GFCI. All of the wires go through the same CT. When the current is going out on one leg, and back in on another, they cancel each other out. And that goes for the current on the 120V as well.
The only time you should have a problem is if there really is a ground fault.

I know that might be a little confusing. Ask more questions if that muddies the water.

After walking by tired butt to the trailer and looking at the GFCI breaker I bought for the job you are correct. It dose have a place to land the neutral on the breaker. The diagram even shows using the 2 pole breaker on a MWC sharing the neutral. It should work OK if not I will just install a SP contactor for the pump and wire it in with the control voltage. I looked up the "personal protective device" that the company that supplied the pump/heater. It was a faceless GFIC with a ct on the back to bring the wires through. Strange and expensive.

 

[LarryFine]

It was a faceless GFIC with a ct on the back to bring the wires through. Strange and expensive.

Not necessarily expensive; they don't have to make and install the main circuit conductive pathway parts.

In many ways, it's a superior design, because the load pathway has fewer connections.

 

[ceb58]

Not necessarily expensive; they don't have to make and install the main circuit conductive pathway parts.

In many ways, it's a superior design, because the load pathway has fewer connections.

Well, it's expensive if you buy from the co. that supplies the pump/heater. Around $200.00