Invertor Loads Not Working

[rpeterson73]

I just finished upgrading my old Heart Interface 20 Source Manager with Xantrex SW 2012. Everything seems to be working well so far EXCEPT I am not getting any power to the invertor load circuits such as microwave and general outlets whether I'm in generator, shore, or invertor modes.

I am getting 120 voltage out of the invertor to the sub-panel in all power modes. I am getting 120 voltage out of the circuit breaker in my sub-panel. I am using two twin 20 amp breakers to power my 3 invertor loads. But why am I not getting any power at the outlets or microwave? Are my neutral and ground bus bars wired wrong?

I did notice that when I measure voltage at one breaker but flip the corresponding twin to off, I still get 109 volts on the breaker I flipped off. How can that be? I thought they are totally independent even though the two breakers are joined.

See attached drawing.

[HarryStone]

Get a circuit tester and plug it in. Like this. https://smile.amazon.com/dp/B000RUL2...mcd_asin_0_img

I'm sure lowes/home depot/harbor freight/Walmart carries them.

It sounds like you have a ground or neutral problem. the tester will tell you.

[andy29847]

The problem is not likely your neutrals and grounds. It is hard to be specific without knowing about the panel and breakers you are using. Many of the Rv sub panels are single buss with no main lug. Power from the inverter goes to a breaker that functions as the "Main". Power from that breaker goes to the other breakers that feed equipment in your coach. I expect that you are not feeding the power from the main breaker to the buss of the panel. Here are a few photos and illustrations from my coach that might help.


Here's how the power works in my coach. It is very similar to your drawing.


Here is my AC sub panel. The breaker marked "inverter" controls the other breakers.


Here is a description of a RV sub-panel I found online.


Good luck! Work safe!

[twinboat]

Are you feeding the inverter power, and jumper, to the supply ( In ) side of the 2 twin breakers ?

Send a picture of that panel, cover off.

[rpeterson73]

Thanks for the input so far.

I have attached three additional photos.

I have the invertor AC out coming into the circuit box which is the orange wire. Attaching black to the power bus, white to one bus bar, and ground to another bus bar. I'm using the white heavier gauge wire to jump the hot to both breakers. Not ideal but this is the smallest box I could find.


I have the three wires going out to the invertor loads. Black wires to other side of each breaker. White wires to the neutral bar and ground wires to the ground bar.

I am getting 118 volts coming out of each breaker so I know I have power at least this far. But why the heck is nothing working?

I mentioned this earlier but this still seems weird to me. Take the twin breaker on the right in the picture. If I flip the switch on one of them and keep the other one one, I still get voltage in the one I flipped off. It goes down from 118 volts to about 110 volts. The one left on stays at 118V. Shouldn't voltage go to zero in the one that is flipped off?

[rpeterson73]

Oh yeah, and one other thing. In the close up picture of the bus bar, there's a plastic laminated like card wedged between the bus bar screw and the casing of the panel box. Is this to prevent conduction betweent the two? Seems like a strange and flimsy method if so.

[andy29847]

Originally Posted by rpeterson73

If I flip the switch on one of them and keep the other one one, I still get voltage in the one I flipped off. It goes down from 118 volts to about 110 volts. The one left on stays at 118V. Shouldn't voltage go to zero in the one that is flipped off?

Danger - Danger - Danger

Off should be off. You have to find out where that power (~110v) is coming from!

[andy29847]

Originally Posted by rpeterson73

I mentioned this earlier but this still seems weird to me. Take the twin breaker on the right in the picture. If I flip the switch on one of them and keep the other one one, I still get voltage in the one I flipped off. It goes down from 118 volts to about 110 volts. The one left on stays at 118V. Shouldn't voltage go to zero in the one that is flipped off?

This is a guess. We need to know more about your inverter/charger to be certain, but I think you have the white lead in the orange cable from the inverter hooked up to a load terminal on the inverter. It should be on the neutral terminal.



Proceed with caution! Disconnect all power (AC and battery) to your coach before you start unhooking wires.

[andy29847]

Expected measurement with a volt meter - all breakers in this panel off.



A - B = 0v
A - C = 120v
A - D = 120v

C - D = 0v
C - E = 0v
C - F = 0V


From what you have written, I expect you will find C-D = 118v

[KanzKran]

Originally Posted by rpeterson73

I did notice that when I measure voltage at one breaker but flip the corresponding twin to off, I still get 109 volts on the breaker I flipped off. How can that be? I thought they are totally independent even though the two breakers are joined.

Shut incoming power off, including the inverter, check that it's dead, then lift the black wire off that breaker. Stick a wire not on it for protection. Turn the power back on, and check the voltage at the offending breaker, and on the wire with the wire nut on it, carefully of course.

Is there voltage on the breaker lug, and especially, on that loose wire?

[rpeterson73]

Thanks again for the input everyone. Sorry to waste everyone's time but I'm an idiot. As it turns out, the neutral wire from the AC out of the inverter had come loose and was not making contact. I couldn't see it b/c it has a cover plate. I'm glad some of you pointed out that area of concern. I'm not sure how long it would have taken me to remove the cover plate and check there. You all saved me a lot of time and effort. Problem solved. Now on to the next project.

[Ray,IN]

Glad you found and fixed the problem!