50 AMP Electrical and Low Voltage

[ret2006]

During this very hot summer while camping at older COE parks the voltage gets very low especially if there are many RV's with two A/C's all running. I know that if the volts go lower than about 107 it can damage the compressor to the air conditioners. I have two air conditioners in my 5th. wheel.
My question is about how 50 AMP service works. I have a Progressive EMS-PT50C. While reading the digital display it shows L-1 with the voltage, current, frequency and any error codes, then it goes to L-2 with the same information. I think that with 50 AMP service the 240 volts coming in to the park pedestal is split into two "legs" of 120 volt each before going through the RV cord to the camper. Recently during the heat of the day the reading on L-1 would show 107 volts and L-2 would show 103 volts but the Progressive unit would not shut down the electric. (Progressive shows that less than 104 volts it will cut the power to the RV), at 107 on one leg and 103 on the other it is still going. Should I be concerned about this low voltage for an extended period of time?
If someone would educate me on how the 50 AMP electrical works I would appreciate it. Should I be concerned about this low voltage or just allow the Progressive unit to take care of it for me.

[Acableguy06]

50 amp service is 240Vac The vary same type of plug that you would find at your dryer and electric range in your house built to new code. Each one of the legs has 120Vac 180 degrees rotation from each other. Therefore on a 50 amp service you have 50 amps available on each 120Vac line for a combined 120Vac amperage of 100 amps or 50 amps 240Vac. These lines come in for the pole this way, unless the campground cheats the system and runs 120Vac 50 amps and splits it in pedestal (against code).

The reason you get different readings on each leg is because it depends on how much draw is on each leg of the 50 amp service. For a camper with 2 air conditioners each one will be hooked up to one of the legs, and usually the other systems are tied to only one of the legs which creates an unbalanced load. Hope this made sense.

In regards to the progressive system I am unfamiliar with the system.

[Herk7769]

http://www.forestriverforums.com/for...ers-26202.html

http://www.forestriverforums.com/for...n-24971-2.html

You need an autotransformer...

[TURBS]

Originally Posted by herk7769

http://www.forestriverforums.com/for...ers-26202.html

http://www.forestriverforums.com/for...n-24971-2.html

You need an autotransformer...

Wish those darn electric stealers weren't so expensive!

[Herk7769]

Originally Posted by f1100turbo

Wish those darn electric stealers weren't so expensive!

You might think differently when your AC is running and the DW is a happy camper. "Been there; done that" when AC won't kick over and it is over 110 heat index in the camper.

[TURBS]

Originally Posted by herk7769

You might think differently when your AC is running and the DW is a happy camper. "Been there; done that" when AC won't kick over and it is over 110 heat index in the camper.

Lol no I want one! but man I wish I had the jack to lay down for one is my point!

[Herk7769]

Originally Posted by f1100turbo

Lol no I want one! but man I wish I had the jack to lay down for one is my point!

It does help that the Franks units have an integrated 6000 Joule surge suppressor (per leg) and "correct wiring" checker. Subtract what those cost from the unit price of the Franks and you are getting the autotransformer for about 150 bucks.

[TURBS]

Originally Posted by herk7769

It does help that the Franks units have an integrated 6000 Joule surge suppressor (per leg) and "correct wiring" checker. Subtract what those cost from the unit price of the Franks and you are getting the autotransformer for about 150 bucks.

Is "Frank's" the only brand ?

[Herk7769]

Originally Posted by f1100turbo

Is "Frank's" the only brand ?

No, but IMO it is the best one out there for the price. While I am a big fan of his product, I have no financial interest in his company. Frank is a cool guy to talk to and when you call to get a price, take the time to chat with him. Mention the Forum as he is pretty stoked about getting the new business.

A real "Tom Edison" inventor type.

Franks' units are the only 2 stage autotransformers out there. At 8% (low boost) and 16% in "high boost" it has the highest boost available. All the other units are single stage "on or off" and vary from 8% to 10% of voltage boost.

Powermaster used to be his main competition until he was caught reverse engineering some of Frank's patents (Powermaster is now out of business, but you can still find his orphaned units on eBay).

Hughes also makes autotransformers.

[wmtire]

Originally Posted by ret2006

My question is about how 50 AMP service works.

This is my understanding of 50 amp service, and let me see if I can put it in Layman's terms without getting too technical.

Most experienced camper owners fairly understand the common 30 amp service. It's 110 volt, and you are limited to using a total 30 amps of electrical stuff in your trailer at the same time. Most have learned that you have to turn some things off in your trailer.... when using toasters, hair dryers, and other things that take a lot of electricity to power or you will trip the breaker(s).

Now with a 50 amp service, common sense says that you now have 50 amps of total power, as the name applies, versus the 30 amp previously discussed. The 50 amp service is 220 volt (2 X 110), but the service is actually split into two 110 volt sides....EACH with 50 amps.

So, in reality you have TWO (2) fifty amp lines....or a total of 100 amps when connected this way.....or as your monitor says L1 and L2. This is over three times as much as a 30 amp service.

Because you have 100 total amps (over 3 times as much as a 30 amp), you can run all kind of electrical stuff at the same time now. 2 air-conditioners, water heaters, microwaves, toasters, hair dryers. etc. You are still going to limited to the individual circuit breakers for each outlet. It's so much better than a 30 amp service.

Unless you get into some higher-end coaches, nothing in your travel trailer actually uses 220 volt, but everything works off of 110 volt either on your L1 or L2 sides. This is the part that confuses a lot of people.

The sides (L1, L2) share a common 50 amp breaker and plug-in in the campground pedestal, so if there is a problem on either side, then the breaker trips....shutting down both sides. It might not be as confusing if the breaker had printed on it 50(x2). LOL


Hopefully, this gives an easy understanding of the differences between 30 amp and 50x2 amp trailer service.. If anything is too out of whack, I'm sure my friends here can educate me more.

[Herk7769]

Originally Posted by wmtire

If anything is too out of whack, I'm sure my friends here can educate me more.

Nope, right on.


Great article

[youroo]

Originally Posted by Acableguy06

50 amp service is 240Vac The vary same type of plug that you would find at your dryer and electric range in your house built to new code. Each one of the legs has 120Vac 180 degrees rotation from each other. Therefore on a 50 amp service you have 50 amps available on each 120Vac line for a combined 120Vac amperage of 100 amps or 50 amps 240Vac. These lines come in for the pole this way, unless the campground cheats the system and runs 120Vac 50 amps and splits it in pedestal (against code).

The reason you get different readings on each leg is because it depends on how much draw is on each leg of the 50 amp service. For a camper with 2 air conditioners each one will be hooked up to one of the legs, and usually the other systems are tied to only one of the legs which creates an unbalanced load. Hope this made sense.

In regards to the progressive system I am unfamiliar with the system.

Are you sure that the Dryer outlet is the (Same) as a 50 RV ? If so no wonder people are frying their units. I though we had (Elec.codes)! Youroo!!

[TURBS]

Ok if that's the case can we not run two "30" amp legs through our cord and put in a 50 amp distribution panel and run each 30 amp leg to each side of breakers.
Much like a house hold panel?

I'm assuming that's what a 50 amp distribution panel does.

One 50 amp 110 down left side
One 50 amp 110 down right side.

Why wouldn't they do that anyway with a 30 amp panel?

[TURBS]

Originally Posted by f1100turbo

Ok if that's the case can we not run two "30" amp legs through our cord and put in a 50 amp distribution panel and run each 30 amp leg to each side of breakers.
Much like a house hold panel?

I'm assuming that's what a 50 amp distribution panel does.

One 50 amp 110 down left side
One 50 amp 110 down right side.

Why wouldn't they do that anyway with a 30 amp panel?

Nm I figured it out in my head!

[OldCoot]

Originally Posted by f1100turbo

Nm I figured it out in my head!

Other than politicians, that's where most figuring is done.

[TURBS]

Originally Posted by dunnnc

Other than politicians, that's where most figuring is done.

You no it!

[VinceU]

Originally Posted by youroo

Are you sure that the Dryer outlet is the (Same) as a 50 RV ? If so no wonder people are frying their units. I though we had (Elec.codes)! Youroo!!

Actually the (2) 50 amp and (2) 30 amp plugs are similar but different. They each have an individual NEMA number and purpose.

[wmtire]

Originally Posted by herk7769

Nope, right on.

Originally Posted by wmtire

So, in reality you have TWO (2) fifty amp lines....or a total of 100 amps when connected this way.....or as your monitor says L1 and L2. This is over three times as much as a 30 amp service.

Because you have 100 total amps (over 3 times as much as a 30 amp), you can run all kind of electrical stuff at the same time now. 2 air-conditioners, water heaters, microwaves, toasters, hair dryers. etc. You are still going to limited to the individual circuit breakers for each outlet. It's so much better than a 30 amp service.

Thanks for the acknowledgment, Lou. Much of my education has been gleaned from yours and everyone else's great posts here in the forums.

It also is easy to understand why some campgrounds charge more for using the 50 amp service, as those campers have the potential to use over 3 times as much electricity as their 30 amp neighbor.

[Herk7769]

Originally Posted by wmtire

Thanks for the acknowledgment, Lou. Much of my education has been gleaned from yours and everyone else's great posts here in the forums.

It also is easy to understand why some campgrounds charge more for using the 50 amp service, as those campers have the potential to use over 3 times as much electricity as their 30 amp neighbor.

Yep. I got that lecture at the campground I stayed at over the 4th of July weekend. When we were having power issues and the campground "maintenance guy" saw my Franks unit he tried to accuse me of using a "cheater" to get 50 amp service from a 30 amp site using a "Cheater Box."

When I pointed out that to use that kind of box I would need to have a 50 amp cord somewhere (and I did not) and would need a plug into both the 30 and the 20 amp sockets; not just one in the 30 amp socket. He finally backed off. I had to explain what an autotransformer/line conditioner was as he had never actually seen one before. He HAD seen 50 amp units reserving 30 amp sites to avoid paying for a 50 amp site; then using cheater boxes to steal the extra power.

[TURBS]

Originally Posted by herk7769

Yep. I got that lecture at the campground I stayed at over the 4th of July weekend. When we were having power issues and the campground "maintenance guy" saw my Franks unit he tried to accuse me of using a "cheater" to get 50 amp service from a 30 amp site using a "Cheater Box."

When I pointed out that to use that kind of box I would need to have a 50 amp cord somewhere (and I did not) and would need a plug into both the 30 and the 20 amp sockets; not just one in the 30 amp socket. He finally backed off. I had to explain what an autotransformer/line conditioner was as he had never actually seen one before. He HAD seen 50 amp units reserving 30 amp sites to avoid paying for a 50 amp site; then using cheater boxes to steal the extra power.

Basically Lou when u pay for a 30amp site you get every amp u pay for lol.