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50 Amp Shore Service

Yahoo Message Number: 13956
Can anyone advise me as to the specifications necessary to provide 50 Amp service to the coach? I am in the process of upgrading my home service to 400 Amps and dropping a 100 amp subpanel to my shop. I'm planning to run 50 amp service from the shop to an outside location for the coach? I know this is probably pretty simple stuff but I want to be clear with my electrician. And I'm a woodworker, not an electrician. Thanks.

Kevin Barron

98 Intrigue 40 #10550

Re: 50 Amp Shore Service

Reply #1 –
Yahoo Message Number: 13959
Hi Kevin,

Show the electrican the male plug on the end of your shore power cable - you want a receptacle to fit it and a dual 120 vac 50 amp circuit breaker to feed it.
Fred Kovol

Re: 50 Amp Shore Service

Reply #2 –
Yahoo Message Number: 13960
Fred,

Thanks. How is this different from 220v / 50amp service?

Kevin

Re: 50 Amp Shore Service

Reply #3 –
Yahoo Message Number: 13961
Hi Kevin,

Different - electric dryers take 240 vac (no neutral, just a safety ground). This connection is 4 wire - 2 120vac legs at 50 amps each, a neutral return and a safety ground. It is true that between the 2 legs the voltage is 240vac, but in your coach only 120vac is used with 50 amps on each leg or a 100 amps total capacity.
Fred Kovol

Re: 50 Amp Shore Service

Reply #4 –
Yahoo Message Number: 13966
Fred,

Isn't it 25 amps each leg with a 50 amp total capacity?

Arthur Block

02 Intrigue 11332
98 Chev Metro Toad

Re: 50 Amp Shore Service

Reply #5 –
Yahoo Message Number: 13968
Hi Art,

It's 50 amps each leg for shore power. Look at the main breakers in your circuit breaker box.

With a 8kw generator, it's 33.33 amps per leg.
Fred Kovol

Re: 50 Amp Shore Service

Reply #6 –
Yahoo Message Number: 13972
Fred,

You may be correct, but consider this:

1) A 30 amp circuit is rated for 30 amps and "breakered" for 30 amps at various campgrounds.
2) Seems that a jump to 100 amps would be a bit much - where as 50 amp (25 each leg) seems more in keeping with a capacity increase projection.
3) Most campgrounds with 50 amp service have dual 25 or 30 amp breakers on the pole to accommodate 25 amps per leg.
4) My 8.5 KW generator has dual 25 amp breakers to accommodate 25 amps per leg (even though, in theory, it could deliver 35 amps per leg)
5) Not sure why there are 50 amp breakers in the coach (I need to take your word on this since my coach is not handy to check it out), but keep in mind that breakers are needed to protect the wire from overheating from too much current passing through too thin a wire. Maybe the coach is wired with 50 amp cable on each leg to the circuit breaker box.
6) I have a 50 amp outlet in the back of my home where I park my coach. It is protected by dual 25 amp breakers. I have run both airs, along with the microwave and plenty of lights, along with a coffee pot and have not poped the breaker in the four years I have use the outlet. I pop the 20 amp (?) breakers on my inverter all the time.

I believe that we call it a 50 amp service because it is 50 amp service and not 100. Like I say - I could be wrong. What do you think?

Regards,
Arthur Block

02 Intrigue 11332
99 Chev Metro Toad

50 Amp Shore Service

Reply #7 –
Yahoo Message Number: 13975
Kevin

Quote
>Can anyone advise me as to the specifications necessary to provide
50 Amp service to the coach?

This must be 240 volts, 50 amps each leg. Wire it just like the electric range or oven that has 240 volt heaters and 120 volt lamps.
Your coach uses only 120 VAC loads, as some have written, but must have 240 VAC as the neutral lead can not handle 100 amps.
With every thing running on 50 amp 240 volt shore power, you might have 60 amps on one hot lead, 53 amps on other hot lead and 7 amps on neutral lead.
With every thing running on 50 amp 120 volt shore power, you might have 60 amps on one hot lead, 53 amps on other hot lead and 113 amps on neutral lead. Yes, 113 amps in a wire sized for 50 or less.
In VA recently, we had 50 amp service in a 40 year old park. Our coach indicated only 30 amp service was available and so kept switching off some appliances to meet 30 amp limit. I think the energy management system (EMS) was measuring only 120 VAC & so expecting only 30 amps available. The EMS can't see the park outlet, it must use voltage to figure available power.
So if you wire 50 amps, 120 Vac to your coach, it will probably only use 30 amps. 30 X 120 = 3600 watts. Given 240 VAC, 50 amps, your coach will use up to 12,000 watts. 240 X 50 = 12000.

Eric Elliott
5 Inspire 51321

Re: 50 Amp Shore Service

Reply #8 –
Yahoo Message Number: 13977
Eric, you describe it perfectly -- 240V between the two hot legs, 120V between each hot leg and neutral. Neutral will then carry between 0 and 50 amps, depending upon load balance.

However, while 60 amps on one leg and 53 amps on the other leg will produce 7 amps on the neutral, the example would have been better with 50 amps and 43 amps -- because each leg is protected with a 50 amp breaker which would have tripped in your example. :-)

As I have posted before on this forum: 30A service is ONE 30A 120V circuit (being shared by two legs in the coach using the 50A-30A adapter which splits the one circuit to both legs). 50A service is TWO 50A 120V circuits (one for each leg in the coach). If evenly balanced, 50A provides a total equivalent of 100A, vs the 30A -- there 333% more power with 50A service. This is a good trivia question in camp.
Herb

Allure 2002 #30690

Re: 50 Amp Shore Service

Reply #9 –
Yahoo Message Number: 13984
So, how does the inverter/converter affect all this? It appears that the shore power and generator output power all runs through the inverter/converter. Therefore, the loads I would think it would be limited to the capacity of the breakers on the inverter/converter.
In my case, my Heart 2000 would be limited to two 15A circuits.
Therefore, a total of 30A load.

Jim Hughes

2000 Allure #30511

Re: 50 Amp Shore Service

Reply #10 –
Yahoo Message Number: 13986
Hi Art,

Let me answer your questions:
1)The campground 30 amp breaker is 120 vac. With the 30 amp adapter, you are feeding a one leg 120 vac to both legs in your coach. That's what the adapter does. So you get 120 vac instead of 240 vac and 30 amps total feeding the coach. By the way, for a 30 amp standard trip curve circuit breaker, at a 30 amp draw, it may take several hours for the breaker to trip, instant trip is 60 amps for that 30 amp breaker.
2) It is 50 amps each leg; look at your coach circuit breaker panel - main breakers; look at the breakers in the RV park - there are two 50 amp breakers.
3) Simply not true. There is a single 20 amp, single 30 amp and dual 50 amp breakers which are wired to the appropiate outlet.
4) I can't speak for yours, but the 8kw GenTech has two 35 amp circuit breakers and the generator is capable of delivering 33.33 amps per leg.
5) The coach is wired for dual 50 amp from the shore plug through the interrupter, the transfer switch to the circuit breaker panel. The same wiring is inplace from the generator to the transfer switch.
6) There are 4 circuit breakers on a 2000 watt heart converter - one
for 120vac input, one for the charger, one to the uwave outlet and one to the other outlets with one GFI outlet first inline.
It is called a 50 amp service but has a 100 amp capacity. Your dual 25 amp house outlet is therefore called a 25 amp service.
Fred Kovol

Re: 50 Amp Shore Service

Reply #11 –
Yahoo Message Number: 13987
Hi Herb,

If you have 50 amps in each leg, the neutral will be carrying between 0 and 100 amps. The neutral is designed to handle 100 amps. (Now in 3 phase service, a neutral can have a current in a Y connection if the loads are not balanced and a circulating current in a delta connection, but in contrast to single phase service, the neutral has little are no current. But this is single phase voltage.) Load balance by the owner in operating appliances does nothing other than keep one leg from going over 50 amps and tripping the circuit breaker in that leg. Now if you could plug in a 240 vac appliance, things would be different. Take a look at your CB panel - each leg feeds one a/c, one leg feeds the converter and the other the hot water heater. The converter feeds two outlets - one to the uwave and one to the GFI outlet which feeds the rest of the outlets. The balance is in place; operating too many applaiances at one time will probably trip the converter CB.

Your first and second paragraphs are incorrect.
Fred Kovol

Re: 50 Amp Shore Service

Reply #13 –
Yahoo Message Number: 13999
I am doing the same thing but not until April so any answers to your question will be of interest to me also.

 We are running buried conduit between the two buildings now and while the trench was open added spare conduits for telephone and cable (suggested by CC owners).

 With cell phones and satellite TV we may never use the conduits but it was relatively inexpensive to buy the material and bury it while the trench was open.

Re: 50 Amp Shore Service

Reply #14 –
Yahoo Message Number: 14000
Dave,

Will do. But if you follow the threads to my original post, and don't get as confused as I am, we might just figure this out.

Kevin Barron

98 Intrigue # 10550

Re: 50 Amp Shore Service

Reply #15 –
Yahoo Message Number: 14005
Fred:

That surprises me that you say the neutral is designed to carry 100 amps. While that yellow 50A shore power cord is BIG, I can't imagine that it contains a #3 gauge Neutral wire require for 100A! Wouldn't it be bigger and thicker than it already is?

The wires (two hot and neutral) on the SurgeGuard are all the same size, and are not #3. Therefore, I still maintain that the neutral should not exceed 50A.

If properly wired, the two hot lines should have a 240V potential between them, and 120V to ground. Then if the two 50A circuits were fully loaded, the neutral would be zero amps, NOT 100A. Test it yourself with a clamp-on ampmeter. If only one leg is drawing 50A and the other is drawing zero, the neutral be also be 50A.

Herb

Re: 50 Amp Shore Service

Reply #16 –
Yahoo Message Number: 14018
Hi Herb,

You are right - the neutral carries the difference between the current in the two legs for a 240vac configuration to maintain 120vac across each leg. If the nuetral opens, then the voltage drop across each leg is based on the load(resistance) in each leg.
Fred Kovol

Re: 50 Amp Shore Service

Reply #17 –
Yahoo Message Number: 14040
Art,

Make sure your electrican puts the 50 amp box on the wall or stand the right way. Our electrican did everything right but he put the outlet upside down and it had to be turned around.

Re: 50 Amp Shore Service

Reply #18 –
Yahoo Message Number: 14044
Art I wish I had a off/on switch or breaker at the outlet if you turn off the juice when you plug in it prevent arking and possible damage to you outlet and or plug Bill Vincent

Re: 50 Amp Shore Service

Reply #19 –
Yahoo Message Number: 14053
From: "William Vincent" Willie-john@...>
Quote
Art I wish I had a off/on switch or breaker at the outlet if you turn off > the juice when you plug in it prevent arking and possible damage to you > outlet and or plug
If there's no switch on the power pedestal, I simply turn the coach's breakers off before plugging it in or unplugging it. It works for me!

Dick (& Geri) Campagna
'98 36' Intrigue #10571
Mfd: 11/97

Re: 50 Amp Shore Service

Reply #20 –
Yahoo Message Number: 14054
Ok you guys - let's clear the air! When you plug in the shore power cable or turn on the generator, the surge protector is an open circuit to any loads on your coach for 2 min 15 sec, so there no issue here.
For shore power plug removal, you have two options, turn off the CB at the RV outlet(receptible) box or turnoff the main CBs in your panel in the back or side or where ever CCI is installing them. By federal and state law there is a CB at the RV shore power box.
Fred Kovol

Re: 50 Amp Shore Service

Reply #21 –
Yahoo Message Number: 14058
The main reason for turning off the circuit breaker at the camground is safety. While plugging in or out, the hot pins are exposed and your fingers could slip onto them.

Re: 50 Amp Shore Service

Reply #22 –
Yahoo Message Number: 14059
Quote
(snip)  By federal and state law there is a CB at the RV shore power box.
If I had a nickel for every time there's no circuit breaker at the RV shore power box, I wouldn't be rich ... but I'd have a pocketful of nickels .
However, that's over 37+ years RVing.

Dick (& Geri) Campagna
'98 36' Intrigue #10571
Mfd: 11/97

Re: 50 Amp Shore Service

Reply #23 –
Yahoo Message Number: 14060
The main reason for turning off the circuit breaker at the camground is safety. While plugging in or out, the hot pins are exposed and your
fingers could slip onto them.
--------------------------
In addition, I also thought if not making good contact with the common on the plug you could get 240 volts into your coach until the common plug makes good contact.

George Becker
gwb36@...
1999 Country Coach Intrigue
Cummins isc350
Coach #10700

Re: 50 Amp Shore Service

Reply #24 –
Yahoo Message Number: 14061
I don't have a breaker close to my existing 50 A outlet at the house but based on the above comment will consider putting one next to the outside outlet when we wire the new barn.

 Thanks.