Electrical Question

[SoCal_Kevin]

I have my Progressive Industries Surge Guard installed after my Automatic Transfer Switch. My line voltage, as read according to my PI surge guard, is 119 - 120v at 0 amps being used, but drops to 113-115v at 23 amps used (air conditioner). The drop is only on the line w/ the air conditioner. My generator was supplying the power.

Is this normal? If not, what should I consider for troubleshooting purposes?

Recently, while at a park with 50A service, the power in was showing 110 to 115v. When we turned on our air the voltage dropped so that the surge guard cut power to the coach (automatically cuts power at less than 105 volts).

I suspected an issue with the park's power, since the trouble was always during the afternoon when everyone was running their air. Earlier or later, the power was not an issue.

I am not an electrical guru, so I am just trying to understand whether or not I have a problem and where to start looking to solve it.

Thanks in advance for any insights.

[garry1p]

The AC should not pull 23 amps except on compressor power up.
Depending on your AC size 9 to 12 amps running is normal.

However; In the past if you were at a CG and voltage dropped off to less than 108V, you did not catch it and shut down the AC you may had damaged the motor or compressor (shorted windings due to heat) and 23 amps would be a symptom of a failing AC.

The generator should not drop voltage for more than 15 to 20 seconds then come back up to around 120 even at 23amps.

[vic46]

67Cutlass wrote:

vic46 wrote:

ps: I bought a new convertible 67 Cutlass in the spring of 66, would sure like to get that one back!!!!!!!!!!!!!!!!!!!!!!

Vic

ps: happy Canuck Thanksgiving to all!

Here is my 67 Cutlass. This was taken on the 2012 Hot Rod Magazine Power Tour

KOOOOOOOOOLLLLLLLLLLL
Vic

[Lobstah]

Introduce load, drop RPM, drop voltage...then voltage should return to near "normal"...

Jim

[wa8yxm]

That kind of voltage drop on the Generator I suspect is normal.. Generators normally drop a bit when loaded down.

ON shore power.. NOT.

[67Cutlass]

vic46 wrote:

ps: I bought a new convertible 67 Cutlass in the spring of 66, would sure like to get that one back!!!!!!!!!!!!!!!!!!!!!!

Vic

ps: happy Canuck Thanksgiving to all!

Here is my 67 Cutlass. This was taken on the 2012 Hot Rod Magazine Power Tour

[vic46]

67Cutlass wrote:

vic46 wrote:
Thanks for the explanation, that sure makes sense to me. However, what is the likelihood of there being a a problem from the gen? Could one simply connect/insert the EMS on the input side of the transfer switch, power source FROM the CG pedestal? In the power connection cable of the RV.

Thanks, every day is a learning day.
Vic

You can do that, but with the generator, like everything man made, will fail. Who knows how it will. If the voltage regulator tanks and decides it wants to put out 140v what's to stop it?

I'm more comfortable sacrificing the ATS than leaving the gen set output unprotected. It's just as easy to put the EMS on the output of the ATS as it is to install on the input.

Thanks 67!
Decision time. I think the "downstream" from the TS is the good idea. Alternatively, 2 EMS devices however, that idea makes about as much sense as politicians seem to make on either side of the 49th.
ps: I bought a new convertible 67 Cutlass in the spring of 66, would sure like to get that one back!!!!!!!!!!!!!!!!!!!!!!

Vic

ps: happy Canuck Thanksgiving to all!

[67Cutlass]

vic46 wrote:
Thanks for the explanation, that sure makes sense to me. However, what is the likelihood of there being a a problem from the gen? Could one simply connect/insert the EMS on the input side of the transfer switch, power source FROM the CG pedestal? In the power connection cable of the RV.

Thanks, every day is a learning day.
Vic

You can do that, but with the generator, like everything man made, will fail. Who knows how it will. If the voltage regulator tanks and decides it wants to put out 140v what's to stop it?

I'm more comfortable sacrificing the ATS than leaving the gen set output unprotected. It's just as easy to put the EMS on the output of the ATS as it is to install on the input.

[vic46]

67Cutlass wrote:

prism wrote:

vic46 wrote:
Sorry this is not a reply, but a question. Would it not be appropriate for the surge/EMS device to be upstream from the transfer switch? There is no protection for the transfer switch.
Thank;
Vic

I too was wondering about that but maybe OP was worried about needing protection from Gen set also>??

That is correct and how I wired mine. If you want protection from both SP and the gen set then the EMS should be on the output of the transfer switch. In the event a major problem the coach would be protected from either. You might sacrifice the transfer switch, but that's inexpensive compared everything in the coach.

Thanks for the explanation, that sure makes sense to me. However, what is the likelihood of there being a a problem from the gen? Could one simply connect/insert the EMS on the input side of the transfer switch, power source FROM the CG pedestal? In the power connection cable of the RV.

Thanks, every day is a learning day.
Vic

[67Cutlass]

prism wrote:

vic46 wrote:
Sorry this is not a reply, but a question. Would it not be appropriate for the surge/EMS device to be upstream from the transfer switch? There is no protection for the transfer switch.
Thank;
Vic

I too was wondering about that but maybe OP was worried about needing protection from Gen set also>??

That is correct and how I wired mine. If you want protection from both SP and the gen set then the EMS should be on the output of the transfer switch. In the event a major problem the coach would be protected from either. You might sacrifice the transfer switch, but that's inexpensive compared everything in the coach.

[prism]

vic46 wrote:
Sorry this is not a reply, but a question. Would it not be appropriate for the surge/EMS device to be upstream from the transfer switch? There is no protection for the transfer switch.
Thank;
Vic

I too was wondering about that but maybe OP was worried about needing protection from Gen set also>??

[vic46]

Sorry this is not a reply, but a question. Would it not be appropriate for the surge/EMS device to be upstream from the transfer switch? There is no protection for the transfer switch.
Thank;
Vic

[Old-Biscuit]

Generator supplying power.......119 - 120v at 0 amps being used, but drops to 113-115v at 23 amps used (air conditioner).
What else is on that buss in AC distribution panel? Converter charging batteries?
What size generator?

CG power.......high load demand causing low voltage in park

But tightening terminal screws in transfer switch, in AC Distribution Panel, on Circuit Breakers and at inlet power receptacles (main power cord and generator) will definitely help resolve some of the voltage issues

[alkillion]

Please play it safe. If you are not 100% comfortable and confident, dont mess with the electricity. There is enough power flowing in a 50 amp transfer switch to put you in the hospital, or worse!

I assume your power cord is in good shape. Most 50 amp cords are about 8 gauge wire and about 25 feet long. The connectors should be clean and bright with no corrosion.

Again, be safe.

[SoCal_Kevin]

Hello all,

Thank you for your replies. I will check the connections in the ATS and the Surge Protector for tightness and retest. This sounds like the place to start and go from there.

Thanks,