No ac when using shore power 2014 Vegas

johncarolyn · 07-21-2022, 11:50 PM

When using shore power, i have no ac. Voltage appears at breaker panel and on all breakers. If i run generator, all is fine.Any help woul be greatly appreciated. Presently having to stay in hotel in Frankfurt. Kentucky. Should have been camping.

**16ACE27** · 07-22-2022, 12:30 AM

So what happens if you try to run the A/C when on SP?
When did this start happening?
What has changed since it last "worked on SP"?

If you have 120 VAC to the A/C breaker when on SP it should work just like it does on the generator - the change in power source occurs upstream of the breaker panel so 120 VAC is 120 VAC - the panel (and A/C) doesn't care where it comes from.

Your symptoms don't add up.

Bill Johnson · 07-22-2022, 12:37 AM

You say no power in the motorhome at all, but the converter panel has 120 volts? How did you test it? Did you try unplugged from shore power and turning off the main breaker and turning it back on, sometimes breakers don't look like they tripped. Did you plug in a surge protector into the shore power before plugging in the rv to see if the plug was wired right before plugging in. Did you use a meter and see on the back of breaker has 120 volts and have someone turn AC on, does the power go to 0. Just trying to get an idea of what happened

johncarolyn · 07-22-2022, 01:08 AM

Using my fluke i have power at:
Supply receptacle outside
Main control panel between ground and all circuit breakers
Microwave has power
Wall receptacles have power
AC will not come on..
If i turn generator on all works.

johncarolyn · 07-22-2022, 01:12 AM

And your right....makes no sense.

johncarolyn · 07-22-2022, 01:16 AM

And your right....makes no sense.
At home everything worked when plugged in. We unplugged and drove to Kentucky. When we plugged in here no ac.

Chateau_Nomad · 07-22-2022, 01:27 AM

You have power... but what voltage? Did you try RUNNING the microwave, or just noticed the display (clock, etc.) is on?

Do you have any protection from the campground wiring, or are you plugged straight into the pedestal?

Some campgrounds are notorious for low voltage... which without an EMS (electric management system) you risk damage to things like your microwave.

We've been at several "brown out" campgrounds where the A/C turned off... my internal EMS disconnected when the voltage dropped to an unsafe level.

johncarolyn · 07-22-2022, 01:37 AM

Quote:

Originally Posted by Chateau_Nomad

You have power... but what voltage? Did you try RUNNING the microwave, or just noticed the display (clock, etc.) is on?

Do you have any protection from the campground wiring, or are you plugged straight into the pedestal?

Some campgrounds are notorious for low voltage... which without an EMS (electric management system) you risk damage to things like your microwave.

We've been at several "brown out" campgrounds where the A/C turned off... my inte
rnal EMS disconnected when the voltage dropped to an unsafe level.

120 volt was seen on my meter. I did not run microwave. But i ran a rice cooker snd crock pot.

Chateau_Nomad · 07-22-2022, 01:45 AM

Try a high wattage device like the microwave or a hair blow dryer on high... something that uses at least 1500 watts.

Then shut everything off and try the A/C again... just by itself.

Finally, does the A/C make a humming noise like it's trying to start?

**16ACE27** · 07-22-2022, 02:13 AM

Quote:

Originally Posted by johncarolyn

Using my fluke i have power at:
Supply receptacle outside
Main control panel between ground and all circuit breakers
Microwave has power
Wall receptacles have power
AC will not come on..
If i turn generator on all works.

What about between neutral and the hot side of the breakers? An open neutral on the SP side would give your symptoms. In which case, check the ATS connections.

JimOIB · 07-22-2022, 02:30 AM

You could be picking up some voltage on the neutral wire. Depending on how the campground is wired the voltage could be significant. It would mostly impact devices drawing a heavy load like the a/c. The a/c would drop the voltage on the hot and the neutral voltage could go higher meaning a lower potential between hot and neutral. Measure across hot and neutral with a/c off and a/c on. They should be roughly the same. If not then move to another site and see if the problem goes away.

JimOIB · 07-22-2022, 10:48 AM

Quote:

Originally Posted by JimOIB

You could be picking up some voltage on the neutral wire. Depending on how the campground is wired the voltage could be significant. It would mostly impact devices drawing a heavy load like the a/c. The a/c would drop the voltage on the hot and the neutral voltage could go higher meaning a lower potential between hot and neutral. Measure across hot and neutral with a/c off and a/c on. They should be roughly the same. If not then move to another site and see if the problem goes away.

Better method for troubleshooting a neutral to ground voltage.

https://www.ecmweb.com/content/artic...the-receptacle

Bill Johnson · 07-22-2022, 11:04 AM

It worked at home, it worked with the generator try moving to another spot, like your neighbor. If he would let you get close enough to let you plug in instead of him for 10 seconds and see if the ac starts. Try before moving to power a hair dryer or microwave, have your meter plugged into the outlet and check the voltage it.might be to low. I plug my motorhome in the 120 outlet on the side of the garage and I run one air conditioner with no problem. I visited my son in Minnesota and plugged into his garage and ran my air. I think it's the shore power or cord

johncarolyn · 07-22-2022, 11:29 AM

I am in agreement with all you say. There is no voltage from neutral to hot. I am on a 30amp circuit. We are heading to Lake Cathrine in Arkansas on Sunday. I will try again there. Thanks for all the advice.

Bob Nodine · 07-22-2022, 11:35 AM

When thing work from the generator but not shore power you should first suspect a problem with the transfer switch. You could have burned contacts, etc that keep the shore power from working but when you start the generator the contactor in the transfer switch energizes and moved the AC distribution power input from the shore power plug to the generator. That uses a different set of contacts. Pop the panel off the transfer switch and test things with your meter on AC voltage while plugged into shore power. Then start the generator and check things again. Pay attention to the output phase and neutral to the AC distribution panel. If there is power there when the generator is running but not when it is off you have localized your problem to the transfer switch.

**16ACE27** · 07-22-2022, 01:30 PM

Quote:

Originally Posted by johncarolyn

I am in agreement with all you say. There is no voltage from neutral to hot. I am on a 30amp circuit. We are heading to Lake Cathrine in Arkansas on Sunday. I will try again there. Thanks for all the advice.

Well there you go, open neutral. Did you check the Automatic Transfer Switch (ATS) connections? Common issue with the twist on wire connectors.

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