DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   Electrical (
-   -   Generator Transfer Switch Trouble (

wgramer 10-23-2011 01:20 PM

Generator Transfer Switch Trouble
Hi, I installed a 6-circuit transfer switch made by Reliance, and wired it to a Generac 5K watt generator using an inlet box etc. per instructions. I connected all wires from the transfer switch (labeled A to F, black and red) to the various circuits I want to run off the generator power. All of the circuits work great on both "sides" of the transfer switch (A, B, E & F circuits), except for the double pole C&D circuit that is connected to the well pump circuit which is 240v. Whenever flipping the switch on the transfer switch to "GEN" for the C&D circuit, the generator engine strains significantly and then the 20amp fuse on the "D" circuit trips after about 3 seconds. This happens even when the well pump is not demanding any power, i.e., the water pressure is not low enough yet for the pressure switch to kick on (which to me would be similar to a light bulb being off). This happens even when I disconnect the red/black wires for C&D from the double pole breaker in the main panel... I've tried switching the C&D black wires between the black/white wires that were originally in the double breaker (and leading to the pressure switch) and this just causes the breaker to trip on the main panel (for that well pump circuit breaker). Other "tests" have resulted in the 20amp fuse on the generator tripping... I'm using 10/3 wire running from the inlet box to the transfer switch, the plug is L14-30. The wire running from the main panel to the well pump pressure switch is 12/2, with both black and white as hot, no separate neutral.

It seems the problem lies in the transfer switch? I read something in another forum about the load being unbalanced for a 240v circuit? What does this mean? The instructions for 240v circuits in the Reliance manual assume 12/3 wiring, with a black and red for hot, and a white for neutral. Yet none of my 240v circuits are 12/3, they are all 12/2 with no neutral wire which seems to be pretty common. I cannot figure out why the fuse would trip upon sending power through the transfer switch by flipping the switch to "GEN" mode when there is no demand for power by the appliance... the well pump works just fine putting it back to "LINE" mode.

P.S. - the generator is sufficient to run the well pump, that is not the issue.

Any help would be appreciated! Thank you.

AandPDan 10-23-2011 01:36 PM

The load is balanced on 240v by default. You have to watch how you put your 120v circuits as they only draw on one leg.

What model switch? Can you post a pic?

How about disconnecting the well pump and connecting a meter across the leads. Then start your generator and flip the switch. See what you get for voltage.

Do you have loadmeters on this panel?

wgramer 10-23-2011 01:52 PM

Hi, the transfer switch is model 3006HDK by Reliance. Do you mean to disconnect the wires at the pressure switch for the well (the two incoming hot wires, black and white)?

wgramer 10-23-2011 01:55 PM

Yes it has the watt meters on the front of it...

wgramer 10-23-2011 02:34 PM

Here are some pics... showing the two red C&D wires going into the double breaker for the well pump, and the two C&D black wires attached to the black and white wires originally attached to the double breaker. A shot of the transfer switch showing wiring inside, a shot of the inlet box and wiring, and a shot of the generator...

wgramer 10-23-2011 02:43 PM

Picture of the pressure switch for the well... and picture of the label on the side of the pressure tank for the pump down below... I am certain my problem has nothing to do with the pump itself, as I disconnected the two wires on the pressure switch coming from the panel and am still having the same problem.

AandPDan 10-23-2011 02:54 PM

Double check your wiring. I can see the "C" on one of the black and one of the red wires. I can't see either "D." You are positive that the black and white wire that you have came off the double pole breaker for the well?

Back out a bit on the panel shot and take another. Try to get all your connections.

wgramer 10-23-2011 03:28 PM

Yes the black and white both came out of the double breaker before I started anything.... that was confusing to me at first but then I read up on 240v wiring and realized the white was a hot. It should have been recolored but was not, I noticed at the other end of the line at the pressure switch you can see the black dots added to the white wire with a marker.

Here is a picture of the full main panel.

AandPDan 10-23-2011 04:44 PM

If you disconnected the pump at the panel, undoing the white/black wires, and "C" and "D" are correct, then there must be something wrong with the switch

What happens to the watt meters when all this is going on?

wgramer 10-23-2011 05:25 PM

The right side watt meter (D, E & F) gets pinned to max for a few seconds before the fuse blows. The left side does nothing...

This is the second transfer switch... with the first one I installed something happened inside the transfer switch and there was a short, smell of smoke and I found black soot inside when I took the front panel off the transfer switch. Reliance mailed me a new one...

I can't imagine I would get two bad transfer switches and that it must be my wiring. But I've checked and rechecked every connection and it is exactly per the instructions...

Any ideas, or time to call an electrician to come take a look?

AandPDan 10-23-2011 05:53 PM

Since it's a 240v load I would expect both loadmeters to react together, not just one.

Might be time to call for an electrician.

kbsparky 10-23-2011 09:47 PM

If all your connections are correct, you probably have a junk transfer switch. One side is shorted out.

hayewe farm 10-23-2011 11:06 PM

I have the same model transfer switch and use C&D for a well pump. It is wired as you have discribed and works fine. Either you have wires other than C&D or a defective switch. Check continuity between C&D and see if they are shorted.

wgramer 10-25-2011 11:51 PM

I removed the bar that ties the C&D switches together on the transfer switch. If I flip C to "GEN" mode (without the generator even running outside) nothing happens, but if I flip the D switch to "GEN" the watt meter spikes to max, I can hear a humming sound and the breaker eventually trips. So it seems like the D line is my problem. I opened up the transfer switch and all wires inside seem fine, all look connected properly etc...

What could cause the D circuit to draw so much power in GEN mode when the generator is not even turned on??? Where is the juice coming from and why only D and not both C&D? All the other circuits work just fine. If I turn off the well pump breaker then of course neither C nor D do anything in GEN mode. Could there be a problem with the double pole breaker for the well pump in the main panel?

hayewe farm 10-26-2011 12:31 AM

With the "D" switch on Gen you are connecting the breaker to the gen input on breaker "D". It sounds like the gen input to the "D" breaker is shorted to ground or common.

All times are GMT -5. The time now is 07:58 PM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1