NOTICE: State Park Over Voltage Causes RT Transfer Relay Problem!

[BoiseAndy]

Hey Folks:

I was prepping my 2005 RT 210P for a camping trip as usual - plugging into my house 20amp to top off batteries, cool fridge, check appliances etc. Everything worked just as usual.

Went to State Park and "Plugged In". 30 amp with inline surge protector. The Transfer Relay (5000 Series Progressive dynamics) began to "click" at 1/2 to 1 second intervals and causing the the Main Charger unit to freak out cycling on and off every second. The outlets in the media cabinet and over the sink were cycling too. Changed to 20 amp circuit without surge protector. Same issue.

Everything was fine on generator, and the inverter when engaged did energize these outlets.

After 4 hours of diagnosis - I gave up and shut off the Charger which also stopped Relay cycling. But I did notice that the park outlets read 125 VOLTS on my meter.

Came home and had a "middle of the night eureka" that 125 volts may have been the issue? Sure enough - plugged the RT back into house 120 volt this morning and everything is fine.

[SteveWolf]

In the USA and Canada it is 120 volts plus or minus five percent. 125 volts is not over voltage. Did you check if the hot and neutral were reversed? I don't think it could be a ground problem as you'd see that on the surge protector.

You'd check a reversal by finding 110 volts across the neutral and ground and zero volts between hot and ground.

Steve

[BoiseAndy]

I did not check if hot and neutral were reversed. I took it for granted that this State Park who has hundreds of guests per month and is open year round would have correct polarity. Would this be something that could have been an issue here for months or years and no one ever noticed?

I did not consider 125 volts an issue at first in my diagnostics because of the +- 5% but perhaps the transfer relay has a more limited tolerance?

[mkguitar]

I work with electronics- musical gear
I check power with a meter before plugging in every time


Same with my van in a campground



always check before plugging in- I've found all kinds of issues at pedestals


It seems they get hit by drivers, and then "repaired" by an idiot



As above "line voltage" has been creeping up in North America- it is not unusual to see 125+




"normal" readings would be no more than 5 volts between neutral and ground, 120 volts hot to neutral and hot to ground



mike

[SteveWolf]

I had a reversal at my home which put power on the old Class A chassis. Found that out fairly quickly. First time I grabbed the door handle. Heck of a burglar alarm. The burglar brings his own siren when he screams.

It probably isn't a reversal.

If it is a persnickety relay you will be seeing the problem again. The "shut off the charger which also stopped the relay cycling" is the key. Don't know why, but the charger didn't like the pixies.

Steve

[BoiseAndy]

Many Thanks for the fine responses. Learning how to check for reversal and that the charger was more likely sensitive to the power than the relay is MOST useful information.

Regards, ANDY

[JohnnyFry]

"Voltage Creep" is a valid point. In my lifetime it has gone from 110 volts to 115, then to 117 and has been stated as 120 for the past few years. I am not sure exactly why, but power in large apartment and condo complexes is typically derived from 208 volt 3 phase Wye connected systems where the phase/neutral is 120 volts. Possibly the power companies simply had single phase transformers wound to 120/240 volt single phase power typical in residential situations for uniformity. A further note for those traveling below the border: normal power distribution in Mexico is derived from 220 volt wye connected 3 phase transformers which deliver 127 volt phase to neutral. I never had any problem using 127 volt power in Baja, but I did have to disconnect my Progressive Dynamics device to do so. I always monitor my incoming line voltage 24/7.

[booster]

I think the increases are also tied to the fact that we are using so much power these days that high load sag, AKA brownout, is getting all too common. With all the sophisticated electronics in use, particularly in factories, a browonout shut down, equipment drop out, can be a very expensive thing to have happen from equipment damage, scrap produced, lots production time, etc. We used to deal with it all the time an my last job along with losing one phase of the 3 phase power which was even worse because all the big motors would overheat very quickly so all had to be shut off and when you have literally more motors by far than employees trained to be able to do the shutdowns is looked like a hamster race as everyone ran around the whole building, and the roof, killing everything.


Staying a little higher gives more window before serious issues and at 120 it matches the 3 phase transformers that take 440v 3 phase to 120v.

[Texasnielsen]

Can’t say what your specific issue was at the SP as I am not an electrician. However I will not plug my van into a source without one of these. They are not cheap however it is better than having problems with incorrect wiring at the variety of parks we visit when not on solar-only. ( I am not affiliated in any way to the listing or the product).

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[Paga]

Boise Andy:

When you measured the park outlets being at 125 volts, did you take that reading on the actual voltage delivered into your RV, under the load you had at that time?

As you know, the voltage can drop under load especially if the park equipment has a poor connection or device in that specific circuit. The site next to it may be just fine.

If the park voltage wasn't dipping each time your transfer relay dropped out, then under voltage was not your problem. The symptoms do suggest a line voltage drop under load.