how do i tell if 50 amps is coming through plug.

[karaokegal]

i own an RV storage facility and have 50 amp plugs onsite for my customers. The plugs and wiring was done by a licenced electrician. I have one customer who complained that even though the plug is working he is not getting 50 amps because he can not run his AC nor his refrig. I moved the customer and he had same issue at another plug then the 3rd plug worked. I called the electrician out and he said everything was fine. How do I prove to this customer that the plug is putting out 50 amps? Also what could be the cause in the rv that would cause it to work sometimes and not all the time.

[time2roll]

peaches&cream wrote:
If the problem is the RV, why did moving it to another spot fix it?
cwit and I would like to know.

Maybe the 50a twistlock was not fully inserted.
Maybe a breaker in the RV was tripped.
Maybe the transfer switch has intermittent issues.
Trouble was fridge and air conditioning that also require proper 12 volts... maybe an issue with the converter or battery system.
Could also be issues with the energy management system.
Maybe the RV owner wanted a different spot.
The list is endless.

Or maybe it was the outlet and the electrician fixed it to cover up his previous work and just declared he found nothing.

It is a circle of no answers because the RV was moved vs diagnosed while the failure happened. This is what makes electricity tough to diagnose over the internet.

[rgatijnet1]

Judging by the OP's post, I get the impression that he is not that versed in electrical issues. Most of the replies, tho correct, are probably too technical for the OP's purposes. I think the only way to get a correct answer is to call out a different electrician to inspect all aspects of the wiring to insure that everything was wired correctly from the source so that ALL of the 50 amp outlets are capable of supplying the required 50 amp service the customers are paying for.
This can all be done with a physical inspection of the wire gauge, length of run, source capacity, etc, without hooking up a bunch of loads, which would only be valid if the loads were set up on all 50 amp pedestals at the same time to check for voltage drop.
Another electrician will also check for loose connections while he is doing the inspection.
If the source capacity is sufficient and the wire gauge is correct for the run, then a load test will be fine and unnecessary.

[enblethen]

There is a couple variables why it didn't work then it worked.
I would say the rig's cable or connectors are questionable.
Could be cord body at the pedestal end having one partially open or completely open when wiggled.
If the rig has a twist lock connector to attach shore power cord, same as above.
If the rig has a retractable cord reel the slip rings could be burnt, corroded or not making contact.
50 amp shore power is 120/240 four wire. two legs of 120 on different phases, a neutral and a ground.

[hanko]

to the OP, check one or both of the ungrounded conductors with a clamp on amp meter to see what the guy is drawing. probably nothing wrong with you

[hanko]

naturist wrote:
50 amp RV service is really two separate 120 volt, 25 amp circuits, as I understand it. This would suggest you only need a tester capable of drawing 25 amps. 25 amps at 120 volts is 3,000 watts. So get two 1500 watt heaters (probably run you $15-$20 at Wallys -- or heck, you probably have a couple laying around already, as that is the "standard" small space heater wattage). Plug 'em in together on one branch of the circuit, then the other, and if the circuits both support the heaters going full blast for, oh, say, one minute, you got 50 amp service.

Your way wrong on that one. your 50 amp service is classified as 50 amp 230 volt service. You can draw 50 amp on either leg. your capacity is close to 12,000 watts, versus 3600 for a 30 amp 120 volt service

Henry Haigh Electric Co
Haigh Electrical Engineering services

[4aSong]

Like Smkettner said:


It is 50 amp 240/120 volt service.
50 amps at 240 volts, 12,000 watts.
Since RVs only use 120 volts it is the RV equivalent of 100 amps.

http://www.myrv.us/electric/

The 50-amp 120/240-volt 3 pole 4 wire grounding Service

This 50-amp service has 4 wires with two 120-volt HOT feeds. It is a misconception that this 50-amp RV service is something special. This service is a STANDARD 120/240 50-amp 3 pole with 4 prongs used for numerous applications.
From this common service we can draw 120 or 240 volts. Each leg is 50 amps @ 120 volts. 50-amp X 120-volt = 6000 watts. But since there are 2 HOT 120-volt legs at 6000 + 6000 = 12,000 watts to use in the RV or 50-amp X 240-volt = 12,000 watts when used as a 240-volt service.

Almost ALL 50-amp wired RV's use both sides of the service separately as 120 volt on each leg. Only a few mostly high-end coaches utilize the 240-volt from this same service.

The 50-amp 3-pole 4-wire service is superior to the 30-amp service because of the total amperage available.

30-amp 120-volt service = 3,600 watts
50-amp 120/240-volt service = 12,000 watts

An RV 50 amp outlet has TWO 50 amp breakers.

The half round or U is the ground the one directly below it is the WHITE or neutral and the other two black wires are 180 degrees out of phase with each other are the HOT 120-volt. In reality you have TWO 120 volt split service going into your RV.

[pianotuna]

Hi,

If there is a loose wire in the breaker panel of the RV, the act of moving it might cause it to reconnect and work for a while.

peaches&cream wrote:

cwit wrote:
I guess I did't read your statement right either. Sorry .I agree with peaches.

If the problem is the RV, why did moving it to another spot fix it?
cwit and I would like to know.

[peaches_cream]

cwit wrote:
I guess I did't read your statement right either. Sorry .I agree with peaches.

If the problem is the RV, why did moving it to another spot fix it?
cwit and I would like to know.

[wa8yxm]

Sadly there is no way you can prove anything to the customer.

You can test,, I can tell you how to build a test panel, two methods, but thats all you can do.

here is how to test

You need to build a test panel the easiest test panel is a 50 amp RV type service box mounted on a piece of plywood,, You need a PIG TAIL type connector to feed it power,, You will need to expose the black or black and red wires (not bare the copper but expose the black/red insulation) so you can clamp on a clamp on ammerter or.. you can put an in-line ammeter (you need two) on the board.

Circuit breakers (20 amp) to 4 duplex recpticals on each side of the panel
One outlet per breaker

Plug in 4 Space heaters, 1500 watt (12 amp) that's 48 amps, Verify with meter

Move to other side,

That is the only way I know to test to insure you are getting full power

Oh, and measure voltage across the outlet, (240 volts across, 120 side to top or bottom, this assumes round pin at bottom)

[cwit]

I guess I did't read your statement right either. Sorry .I agree with peaches.

[pianotuna]

X2

smkettner wrote:
peaches, I don't think you read what I said. Do you expect the landlord to fix the RV for free?
Because I suspect there was an issue with the RV all along...

[wolfe10]

naturist wrote:
50 amp RV service is really two separate 120 volt, 25 amp circuits, as I understand it. This would suggest you only need a tester capable of drawing 25 amps. 25 amps at 120 volts is 3,000 watts. So get two 1500 watt heaters (probably run you $15-$20 at Wallys -- or heck, you probably have a couple laying around already, as that is the "standard" small space heater wattage). Plug 'em in together on one branch of the circuit, then the other, and if the circuits both support the heaters going full blast for, oh, say, one minute, you got 50 amp service.

Totally INCORRECT. An RV 50 amp outlet has TWO, repeat TWO, 50 amp breakers. So 50 amps on L1 and 50 amps on L2.

Check with voltmeter:

Two outer straights are hots, center straight is neutral and center round is ground.

SO:

From either outer straight to center straight or center round is 120 VAC.

Outer straight to outer straight is 240 VAC.

Center straight to center round is 0 VAC.

THEN, and an important THEN, monitor voltage while he turns on loads-- he will NOT exceed the 50 amp RV capacity with a "regular" RV (excluding some bus conversions).

[time2roll]

peaches, I don't think you read what I said. Do you expect the landlord to fix the RV for free?
Because I suspect there was an issue with the RV all along...

[pianotuna]

Hi,

Get a clamp on multimeter. Have the electrician wire a 50 amp plug that has two 20 amp outlets or 30 amp outlets. Plug in two 1500 watt heaters--one on each plug. Measure the voltage. Then use the clamp on to check the amperage. The amperage should be approximately the same on each "leg", and there should be little voltage drop.



50 amp to twin 30 amp adapter

karaokegal wrote:
i own an RV storage facility and have 50 amp plugs onsite for my customers. The plugs and wiring was done by a licenced electrician. I have one customer who complained that even though the plug is working he is not getting 50 amps because he can not run his AC nor his refrig. I moved the customer and he had same issue at another plug then the 3rd plug worked. I called the electrician out and he said everything was fine. How do I prove to this customer that the plug is putting out 50 amps? Also what could be the cause in the rv that would cause it to work sometimes and not all the time.

[peaches_cream]

smkettner wrote:
Next time call out an electrician before you move the RV.

Explain to the customer if the outlet is found defective it will be fixed, if the RV has an issue it will be $150 for the service call plus any repairs.

And if I was the customer I would tell you "don't waste your time". I'd be gone in a heartbeat and would post on RV.NET. If I'm paying rent it's your obligation to provide the correct service, not mine.