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Sammie · 08-03-2014, 09:49 AM

Sorry for all the dumb questions guys but I'm not familiar with my buddies 2001 Alpine. Can he run both air conditioners at the same time from a 30 Amp service?

Thanks, Sammie

Old Scout · 08-03-2014, 10:08 AM

Yes-- but with many of the same concerns/reservations as your "one AC/15 amp" question--most of the "toasted" campground pedestals I've seen over the years are on the 30 amp connection side--ever wonder why??????
PS--I dont know of any Alpine models that have an OEM-installed energy mgt system that would re-balance or shed load.....

vsheetz · 08-03-2014, 10:09 AM

Depends. Likely yes, if nothing else is operating such as the microwave. Or if there is an EMS that monitors load and sheds one AC as necessary (my 30a service coach does this). Or if there is a capability to cycle back and forth between the two AC units (my son's Winabago does this).

Skip426 · 08-03-2014, 10:22 AM

Neighbor in the park down south did that, 50 amp coach adapted down to 30 both A/Cs on . Power plug & adaptor, melted on the third day.

30>50 amp adaptor , basically supplies each leg of the coach that should have 50 amps; 15 amps. A/C compressor start up load, can run to 17amps , depending on the size of the A/C.
Without the proper onboard EMS, it will over load the circuit.

SteveS · 08-03-2014, 04:29 PM

Sammie - See my reply to your other post "Running A/C on 15 amp"

Sammie · 08-03-2014, 05:16 PM

Quote:

Originally Posted by SteveS

Sammie - See my reply to your other post "Running A/C on 15 amp"

SteveS, I did see your reply and thank you for the very useful information.

Sammie

TRAKKER · 08-04-2014, 05:22 PM

Comment on Skip426 reply. A 50 amp pedestal supplies 50 amps from two separate circuits so you have a total of 100 amps theoretically available. A thirty amp is one circuit of 30 amps. A 30 to 50 adapter at best connects the two prongs on the 50 together. There is still 30 amps available on either leg but no more than 30 together.

Two A/C coaches almost always have one A/C on each leg. However some adapters do not connect the two prongs so one A/C will not work. Nor will anything else in the coach, such as a washer/dryer that is on the second leg. In my experience, the yellow adapters do make this connection but many of the black ones do not.

I have seen home made adapters (and some commercial) that have a 30A male plug and a 15/20A male plug connected to a 50A receptacle so that each feeds one pin. This would be safe only if the pedestal truly had two separate feeds back to the transformer. However if the pedestal just connected one circuit to the two receptacles, you could overload the feed circuit since only 30A would be available.

datrbone8 · 08-04-2014, 05:26 PM

We've done it without issue. On the other hand we can't run one AC on a 15 amp suppy

Sammie · 08-04-2014, 06:21 PM

Quote:

Originally Posted by Rick J Fisher

Comment on Skip426 reply. A 50 amp pedestal supplies 50 amps from two separate circuits so you have a total of 100 amps theoretically available. A thirty amp is one circuit of 30 amps. A 30 to 50 adapter at best connects the two prongs on the 50 together. There is still 30 amps available on either leg but no more than 30 together.

Two A/C coaches almost always have one A/C on each leg. However some adapters do not connect the two prongs so one A/C will not work. Nor will anything else in the coach, such as a washer/dryer that is on the second leg. In my experience, the yellow adapters do make this connection but many of the black ones do not.

I have seen home made adapters (and some commercial) that have a 30A male plug and a 15/20A male plug connected to a 50A receptacle so that each feeds one pin. This would be safe only if the pedestal truly had two separate feeds back to the transformer. However if the pedestal just connected one circuit to the two receptacles, you could overload the feed circuit since only 30A would be available.

Rick, I think you have probably hit the nail on the head. My buddy probably had at least 3 adapters and an added extension cord to get from his coach to the plug outlet in his garage. My next move will be to buy him a new 50 to 20 Amp adapter and of course say a prayer to the electrical gods.

Thanks, Sammie

Old Scout · 08-04-2014, 08:47 PM

Normally, adaptors come in 50 to 30, then another goes from 30 to 20....If you have a voltmeter, test for continuity in the 50 to 30 adaptor--thats the one that splits 20/30 amps to the two legs.

Sammie · 08-04-2014, 09:00 PM

Quote:

Originally Posted by Old Scout

Normally, adaptors come in 50 to 30, then another goes from 30 to 20....If you have a voltmeter, test for continuity in the 50 to 30 adaptor--thats the one that splits 20/30 amps to the two legs.

Thanks Old Scout, I will do that. My buddy put his coach back in storage for the week, so I won't see him until next weekend. I will report back when I find the problem.

By the way, is that Old Cub Scout or Old Boy Scout?

Thanks Again,
Sammie

Old Scout · 08-05-2014, 07:29 AM

.....1963 International Harvestor "Scout"....an oldie but a goodie.....

Sammie · 08-05-2014, 07:54 AM

Quote:

Originally Posted by Old Scout

.....1963 International Harvestor "Scout"....an oldie but a goodie.....

Well, at least your not old enough to have been an Indian Scout.

Thanks for your help,
Sammie ( Old Boy Scout )

Sammie · 08-08-2014, 06:08 PM

To all who answered, your help was invaluable in helping me fix my buddies electrical problem. Rick J Fisher had the answer and hit the nail on the head for me. My initial problem was that I could only get 115 volts on one side of the breaker panel when connected to shore power, but when running the generator I got 115 volts to both sides of the panel. The end result was a bad 30 to 50 Amp adapter. After buying a new yellow ended adapter today at good old CW and plugging in the coach, we now have power on both sides of the breaker panel.

Anyway, I was able to learn something new which hopefully I won't forget with old age creeping in.

Thanks Guys

Sammie