180 Volts AC???

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180 Volts AC???

February 20, 2015, 03:48:06 pm

I fired up my Onan the other day and burned the popcorn in my microwave. I checked the voltage and it read 180. I presumed it was a bad voltage regulator in the Onan but a friend suggested I try shore power and check voltages before I started buying expensive parts. Sure enough, I am getting 180 volts on shore power as well.
Could the problem be in the transfer switch?
Any thoughts?

Re: 180 Volts AC???

Reply #1 – February 20, 2015, 03:52:50 pm

Can't address the 180 on generator-- don't know what generator you have and whether it outputs two hots 180 degrees apart (i.e. 240 VAC between the hots) or just two hots (zero VAC between the hots).

But, if you are on shore power, the #1 cause of that kind of voltage is an OPEN NEUTRAL. So check shore power cord at both ends, Transfer switch and breaker box.

Re: 180 Volts AC???

Reply #2 – February 20, 2015, 04:18:57 pm

Thank you Brett. My coach has an Onan 6.5 Emerald Plus which runs on LP. I'll start looking for an open neutral.

Re: 180 Volts AC???

Reply #3 – February 20, 2015, 04:50:02 pm

Where are you reading 180 volts? Could your meter be incorrect? Did you measure voltage at pedestal? Do you have another voltmeter? Can you open your transfer switch and check for voltage at relay points? While in there look for pitted points? Points/contacts are replaceable on many relays/contactors.

Re: 180 Volts AC???

Reply #4 – February 20, 2015, 05:05:47 pm

Quote from: Barry & Cindy – February 20, 2015, 04:50:02 pm

Where are you reading 180 volts? Could your meter be incorrect? Did you measure voltage at pedestal? Do you have another voltmeter? Can you open your transfer switch and check for voltage at relay points? While in there look for pitted points? Points/contacts are replaceable on many relays/contactors.

The meter is correct. I read it right at the outlet for the microwave, I also checked another outlet powered by my inverter. That voltage was 115. Let me also note that I have a Powerwatch meter that goes up to 130 volts and it was maxed out.
I have the bed up and will be checking voltages in the transfer switch next.

Re: 180 Volts AC???

Reply #5 – February 20, 2015, 05:32:40 pm

At 180V things burn up very quickly. I am surprised the microwave is still working if the voltage is really 180 volts If you have the 50A plug plugged into a pedestal you should have aprox. 115-125 volts between each phase and ground or neutral. If you check between the 2 phases you should get 220-250 volts. If checking between phase and neutral or phase and ground the voltage should be very close to the same. If there is a big swing one way or the other then there is a loose neutral connections somewhere.

Re: 180 Volts AC???

Reply #6 – February 20, 2015, 05:50:27 pm

When I said "shore power" I meant that I plugged into a 2000 watt external generator. That generator is putting out 120 volts but when I plug the shore power cord into it I read 160 volts coming into the transfer switch.
Here's another new clue: When I opened the AC service box, the circuit breaker for the converter was tripped. I reset it and it stays on but there is no change in voltage.
*** I may have shut off the converter when I installed solar panels. CRS.

Re: 180 Volts AC???

Reply #7 – February 21, 2015, 12:07:49 am

After consulting with my buddy George Cooper, who at least a couple of you know, the problem has to be in the transfer switch. I am sending him a photo of the switch assembly and a copy of the wiring diagram and will update this topic tomorrow.

Re: 180 Volts AC???

Reply #8 – February 21, 2015, 09:32:55 am

Actually, with a 50 amp connection (two hots), ANY break in the neutral can result in extreme voltage. Certainly, the ATS is a prime suspect.

Re: 180 Volts AC???

Reply #9 – February 21, 2015, 12:46:29 pm

Edison "proved" that AC was more dangerous than DC; it just took him a while to electrocute the elephant. It certainly is more difficult to understand!

Craig

Re: 180 Volts AC???

Reply #10 – February 21, 2015, 01:09:54 pm

The original posting stated when running the Onan generator the voltage was 180 vac. Point to make, not using a center tap transformer on the genset, normal out put s 120 vac, no 240 nor center tap type. So would love to hear about the Onan with 120 vac out put 2 wire and the theory where the 180 vac comes from ?
The usual cause for high voltage or low voltage on the Onan Gasous units s simply caused by incorrect governor / speed control.

Re: 180 Volts AC???

Reply #11 – February 21, 2015, 04:00:27 pm

Quote from: Dave M – February 21, 2015, 01:09:54 pm

The original posting stated when running the Onan generator the voltage was 180 vac. Point to make, not using a center tap transformer on the genset, normal out put s 120 vac, no 240 nor center tap type. So would love to hear about the Onan with 120 vac out put 2 wire and the theory where the 180 vac comes from ?
The usual cause for high voltage or low voltage on the Onan Gasous units s simply caused by incorrect governor / speed control.

To be clear, the voltage I measured was inside the coach. With the Onan running I measured 180 volts in an outlet and the same at the transfer switch. With ANOTHER generator hooked up to the shore line that was putting out 120 V, I measured 160+- at the transfer switch.
I have an open neutral somewhere inside the coach. The transfer switch appears to be switching between power sources.

Re: 180 Volts AC???

Reply #12 – February 21, 2015, 04:13:35 pm

But is the ATS just switching the hots or it it also switching the neutrals which it needs to do?

Re: 180 Volts AC???

Reply #13 – February 21, 2015, 04:28:28 pm

Quote from: wolfe10 – February 21, 2015, 04:13:35 pm

But is the ATS just switching the hots or it it also switching the neutrals which it needs to do?

I guess that's the million dollar question. All I know at this point is that it "clunks" when the power comes on. It may not be switching anything,

Re: 180 Volts AC???

Reply #14 – February 26, 2015, 06:18:35 pm

The problem was the Onan voltage regulator. The capacitor leaked. Not sure why I got such a high reading from shore power.

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180 Volts AC???

February 20, 2015, 03:48:06 pm

Re: 180 Volts AC???

Reply #1 – February 20, 2015, 03:52:50 pm

Re: 180 Volts AC???

Reply #2 – February 20, 2015, 04:18:57 pm

Re: 180 Volts AC???

Reply #3 – February 20, 2015, 04:50:02 pm

Re: 180 Volts AC???

Reply #4 – February 20, 2015, 05:05:47 pm

Re: 180 Volts AC???

Reply #5 – February 20, 2015, 05:32:40 pm

Re: 180 Volts AC???

Reply #6 – February 20, 2015, 05:50:27 pm

Re: 180 Volts AC???

Reply #7 – February 21, 2015, 12:07:49 am

Re: 180 Volts AC???

Reply #8 – February 21, 2015, 09:32:55 am

Re: 180 Volts AC???

Reply #9 – February 21, 2015, 12:46:29 pm

Re: 180 Volts AC???

Reply #10 – February 21, 2015, 01:09:54 pm

Re: 180 Volts AC???

Reply #11 – February 21, 2015, 04:00:27 pm

Re: 180 Volts AC???

Reply #12 – February 21, 2015, 04:13:35 pm

Re: 180 Volts AC???

Reply #13 – February 21, 2015, 04:28:28 pm

Re: 180 Volts AC???

Reply #14 – February 26, 2015, 06:18:35 pm

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