No power L2

[we_b_tripn]

Arrived at the campground and getting ready to wind down and noticed no power to Line 2 and PI EMS-HW50C is being bypassed.

This gets me one air conditioner running since it’s warm and muggy. Am I risking hurting the transfer switch by doing this as long as all draws on L2 are turned off?
Thanks in advance

 

[TJ&LadyDi]

Do you know if this is related to a bad park power pedestal or has L2 failed somewhere in the coach? If a bad power pedestal, I can't see where there would be any harm done. If the failure is in the coach, then I don't know.

Have you tried rumming your generator to see if L2 comes up?

TJ

 

[we_b_tripn]

I believe it’s the park pedestal. Plugged my Hughes Autoformer and it showing bad L2 just like the PI. We ran the generator in the drive today without issue and just confirmed all is well with it.

I know the bedroom AC is on L1, unfortunately the refrigerator is on the bad leg. And the darn transfer switch hums now! Not sure if it was the quiet with no power or it is me being sensitive.

 

[TJ&LadyDi]

Are you comfortable running the generator, at least until things cool off? I think that's what I would do if the park can't remedy the situation.

Or, can you move to another site, even though it is late. If so, I would first check the new site with the PT50X to be sure you are not dealing with a park-wide issue.

TJ

 

[we_b_tripn]

Boy would the folks here hate us if we ran the generator!

I have the front AC running since it is on L1. Everything else is off except the refrigerator which is running through the inverter tonight.

Nice place but no support after hours. Thanks for the quick guidance TJ.

 

[TJ&LadyDi]

One final thought; have you cycled the power pedestal breakers a few times? Might be worth a shot. Disconnect the coach, cycle the breakers firmly 4-5 times, then reconnect through the PT-50X and see if the fault still exists.

TJ

 

[we_b_tripn]

I had tried that in the course of troubleshooting. I isolated all the L2 draws, turned them off, and bypassed the EMS for the night so we had half power in the coach, i.e. one AC. I have a much better understanding of how my coach is wired regarding the two legs of power. And it is nicely balanced!

This morning the electrician came by and took a look. He tested and claimed 240v and when questioned confirmed he meant 120v on each leg. However he said the wires were very loose and tightened it all up. Seems like that did the trick because we have been good all day. I guess the loose wire dropped the voltage below 104 and everything shut down.

Bill

 

[TJ&LadyDi]

You may know this, Bill, but just a quick refresher on the 240V vs 120V thing. The power company provides a pair of "hot" leads and a neutral (plus ground) in a normal service, whether to an individual dwelling or to an RV park. The two "hot" leads will (or should) measure 240V between them. Measuring between one "hot" leg and the neutral will provide 120V. Thus, 240V is fed to the power pedestal where it is separated into two "buss bars." A third "buss bar" is the neutral leg.

For 120V circuits, the circuit breaker provides the connection to one of the hot lead busses and the other side of the circuit is connected to the neutral buss bar. If the buss bar contact is bad, or the wires coming from the breaker or neutral buss bar are loose, there will be little amperage available and the voltage would drop under any significant load. That would certainly trip the SSP-50XL and give the results you experienced.

Glad you got the problem solved. And, the SSP 50XL did its job.

TJ

 

[we_b_tripn]

TJ,

Your explanation is better than I would have done and is a great refresher for me personally!

Hopefully it helps anyone reading this thread or having power issues such as what I experienced.

Bill

 

[deaton]

Had a similar situation at a park last weekend.

No power on L2 and ok on L1. Progressive EMS showed both legs good. switched to generator an had power on both legs. When generator was off, inverter was drawing down batteries but would not go into charge mode.

called Magnum tech support. They advised testing both legs with meter. Each leg showed 120 volts, but when the meter was put across both legs, irt showed zero volts when it should have shown 240 volts.

Magnum Tech explained the two legs were in phase. They need to be out of phase for the coach to “see” both legs. Fix is turn turn the pedestal breaker off and back on again As advised by @TJ&LadyDi.