Inverter quit working

Alvind · 03-10-2021, 10:01 AM

I am hoping someone can shed some light on this.

The other night we were boon-docking in our 2017 29W and were using the inverter(Magnum Dimension model CSW1012) to power the front TV. We were enjoying a old western movie and as the sun set we became cool. To help conserve the battery for the night, I turn on the generator before firing up the furnace. I left the inverter on.

The generator fired and the transfer switch clicked a few seconds later and the power management display showed 30 amp.

The furnace ran and heated the coach. Once the furnace shut down, we decided to turn off the geny and continue to watch TV via the inverter.
However as the generator shut down the TV outlet was no longer powered.
Turned off the inverter and fired the geny up again. All systems came back on.
Tried to use the inverter once the geny was off and the coach was back on DC only - would not work.

Once home I tried to find out what happened as the inverter will not power the TV

Here is the details:

1. Shore power system works
2. Generator system work
3. DC power system work
4. DC power to the inverter 12.8 volts
5. Inverter “green” status and no fault codes
6. GFCI not tripped
7. GFCI will not test
8. No power on the AC side of the inverter
9. Plugged power via drop cord to inverter AC outlet and the TV powers as it should
10. performed soft reset on the inverter - no change
11. performed hard rest - no change

As anyone had a similar issue?
I saw nothing in the manual warning of a damage potential..

Any thoughts and suggestions is appreciated

chfraser01 · 03-10-2021, 01:47 PM

Until I understood how the inverter is wired, it confused me. On our Seneca, the microwave and the 3 televisions are powered through the inverter. There is a romex that goes to the inverter and if you are plugged into shore power or if the generator is on, that circuit loops back out on the other romex wire (through a contactor relay within the inverter) and feeds the separate breaker box at the foot of the bed that has 3 breakers in it. So if the inverter sees AC power on the coach, that feed just loops through it. If the inverter doesn't see any AC power, it will power up to serve those circuits. If you look on the outlet side of the inverter, you will see the 2 romex wires that have big flat plugs that plug into matching plastic plugs on rubber cords coming from the inverter. We had the contactor relay go out on ours while we were camping so I just removed the plastic plugs from the 2 romex wires and tied them together, black to black, white to white, etc. Once they installed a new inverter under warranty, I installed twist lock plugs on the romex so if that ever happens again, I can just plug the two romex together and leave the inverter out of the loop. Hope that helps.

dvspl · 03-10-2021, 04:34 PM

It sounds like the inverter is working but it's output power is not being transferred to the 120V system. This inverter does not have a pass-thru mode, it relies on an external transfer switch. That transfer switch may have failed. I don't have the schematic for how it's wired, but Jayco will give you one if you ask. Also, to make sure the inverter is working, have you looked at the manual? It has some troubleshooting steps and the unit does provide some fault codes. If you don't have the manual, you can download it here:
https://www.magnum-dimensions.com/fi...token=rHJ1rIwm

chfraser01 · 03-10-2021, 04:40 PM

I am incorrect on this model. I was thinking of the CSW2012 inverter. Sorry

Alvind · 03-10-2021, 06:17 PM

Thank you, and yes I reviewed all of the troubleshooting steps. I even call Magnum’s tech support, they said it might be shot and not worth repairing. I got a number of a guy in Nashville to call tomorrow.
I don’t want to replace and have it happen again. Would like to know the root cause....

If i find out anything i’ll post the details.

Alvind · 03-10-2021, 06:21 PM

Thank you for your post.

My unit has a separate transfer switch and i am wondering if it had a hand in killing the inverter. I’ll post my findings.

dvspl · 03-10-2021, 06:45 PM

Quote:

Originally Posted by Alvind

Thank you for your post.

My unit has a separate transfer switch and i am wondering if it had a hand in killing the inverter. I’ll post my findings.

I finally found the pictures I had taken of the electrical components. The inverter feeds it's subpanel through a separate transfer switch, a Magnum Dimensions CSW-TS15. If the inverter provides 120V from it's GFCI output outlet but doesn't send power to the AC subpanel, then that transfer switch is likely the issue, not the inverter. You can find the manual for the transfer switch here: https://www.magnum-dimensions.com/si...W-TS15-Web.pdf
You can find the switch online for ~$40 at various electrical supply companies.

JimD · 03-10-2021, 07:59 PM

If my inverter is on when I cycle the generator it most often trips the GFCI on the front of the inverter. I have the Magnum CSW1012.

Alvind · 03-10-2021, 08:57 PM

Thanks for the reply. I have tried to rest the GFCI to not avail. I will try again in the morning. That’s for the insight.

JimD · 03-10-2021, 09:08 PM

Quote:

Originally Posted by Alvind

Thanks for the reply. I have tried to rest the GFCI to not avail. I will try again in the morning. That’s for the insight.

I think GFCIs won't reset unless 120 volt power is present so you may need to have the thing powered on to allow the button to be reset.

When I had the problem, which has happened a handful of times, the remote switch is lit and I think (not 100% sure) that I could hear the unit chirp when powering up. Nothing would come out of its outlets until the button was pushed.

Good luck. Hopefully it is something this simple.

JimD · 03-10-2021, 10:13 PM

Attached is the manual for the inverter.

Alvind · 03-21-2021, 08:25 PM

Hello,

After detailed troubleshooting, I have confirmed my inverter no longer is working. Instead of trying to take it apart and determine what circuit failed and send for repairs, I purchased a new one and replaced. (This strategy was recommended by the technical service rep.of the inverter.) I assume it failed either due to a current surge from the generator or current low voltage as the generator stopped. I had left it on when I started the generator and shut it back down.

The only thing I did notice that was worrisome is how the factory installed the inverter. The instructions clearly indicate a caution not to put anything between the DC lugs and the current conductors.
In my case, the factory had place a washer between the lug and conductor. Was this the cause of the failure? I can’t say for certain; but the mfg. of the inverter was concerned enough to include a strong warning against it.

The things I am taking way from this exercise are:

1. Check all electrical connectors against the mfg. manuals
2. Review all operations carefully. Check their operations against the manuals not was is spoken during a PDI. (The inverter on my 2017 Greyhawk is not wired or sized to be used other than to operate the TVs when no other AC power source is available.).
3. Inspect and clean up the electrical area. In my case I found loose connectors and wire scrap, enough to caused a short. I also protected the live DC lug in the floor of the compartment. (May have caused my issue.)

In case you are interested the new converter was $366.00 from Amazon. Replacement took less than 30 minutes.

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