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.

[Empty_Nest__Soo]

I'm not sure what, exactly, happened to cause the RV owner to not be able to operate some things. Did the breaker for your 50*amp power outlet trip? Did the wiring on your side of the outlet burn up?

Wiring will try to conduct whatever current is drawn through it. If the RV is drawing more current than the breaker or wire can provide, either the breaker will trip or the wiring will burn up.

The power should be provided by a single 50-amp 2-pole breaker. This guarantees that the two legs of the circuit are 180* out of phase, as they should be.

If both legs are on the same phase, that could cause problems.

Wayne

[enblethen]

Many larger coaches and trailers have a detachable shore power cord. The rig's end utilizes a twist lock connector. Many are made by Park Power
Park Power
Rig in question is a 50 amp 120/240 volt four wire connection. Not sure what the rig in question is. He could have a power management system that did not detect 120/240 connection. This could be an automatic system or maybe rig's owner tried to do it manually.

[mowermech]

zman-az wrote:

MotorPro wrote:
You didn't say the breaker was poping so amps is totally irrelavent. Are you getting close to 120 volts between L1 and N and between L2 and N under load. If so the problem is in the RV.....end of story.

Not end of story. Amps has everything to do with it along with voltage, you need both. Power = Voltage x Amps

I hate to get involved in these discussions, because most of my electrical experience is in aircraft (115VAC, 400 cycle or 28VDC at up to 800 amps), but I think the point that was being made is that the 50 amp breaker did not pop, so the circuit was not overloaded. Therefore, if the VAC at the plug was 110-120VAC under load, there was Probably no problem with the circuitry to the plug, the problem was more than likely in the RV.
For those who are talking about "twist lock" plugs, I have never seen a "twist lock" on an RV. What trailers or coaches have them? Where can they be plugged in? EVERY RV pedestal I have ever seen has straight plugs for 50, 30, 20, and 15 amp connectors (20 and 15 are the same socket).

[zman-az]

MotorPro wrote:
You didn't say the breaker was poping so amps is totally irrelavent. Are you getting close to 120 volts between L1 and N and between L2 and N under load. If so the problem is in the RV.....end of story.

Not end of story. Amps has everything to do with it along with voltage, you need both. Power = Voltage x Amps

[zman-az]

I have experienced a few times loose connections that make things like AC not work right. My first house had the AC go down one day. Found loose connections at the circuit breaker box and just a quick turn of the screwdriver fixed the problem. Just recently I purchased a 2014 Winnebago Journey with 50amp service. The AC sometimes worked and sometimes did not when on shore power. A quick shutoff to the power and back on fixed the problem. Never had a issue with the genny. After this happened 3 different times I opened up the transfer switch box and put the screw driver on all the terminals. The power cord terminals were snug, but not tight. After I tighten them down problem solved.

You could be seeing something similar either in your pedestals or the customers RV. If you decide to check for loose connections please have someone that knows something about electricity do this for you as you could get shocked if not done properly.

[MotorPro]

You didn't say the breaker was poping so amps is totally irrelavent. Are you getting close to 120 volts between L1 and N and between L2 and N under load. If so the problem is in the RV.....end of story.

[tropical36]

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.

Just so you know, current is drawn by the load as needed and doesn't put it out, as per say. Assuming the outlets in question are indeed 240vac, the question remains of what this customer means by .....he can't run said equipment. Does he have a energy management system that's shedding this equipment above say 30amp? Does he have some sort of protection that trips with low voltage, perhaps? Is he tripping your feeder breaker which if 50amp, may be faulty? Does he possibly only have voltage on one side of these outlets, which would only allow him to run what's on that side of his breaker box and would be my guess or he could have a intermittent breaker box problem of his own, killing the one side. So what is the exact problem? Now that he's happy and things are working with the 3d site, one must wonder and again, he could have an intermittent problem of his own.

[dougrainer]

MrWizard wrote:
People never give the residential house breaker panel second thought unless renovating and older home, they don't move the stick and brick around they are not subject to changes of location and power

But people move their RV, and then come here and ask questions and are surprised by the answers
You and I know the old std is 3600 kva and the new one is 12000 kva
Big difference
Buyers are not really informed of the differences, or the relationship of use

And that is the failure of the RV industry

You are IN the service part, not the MFG part
I am not in the industry at all

Let's just agree to disagree, and you can quit trying to defend the industry short comings

Well, I USED to be a assbly line worker years ago. I have been a Tech for 35 years. I do not see how it is the RV industry that has to explain the why's and do's and don'ts of 30 or 50 amp service as it relates to having a 30 or 50 amp service installed. THAT is not the business of the RV business, but the business of Local Electricians. I guess I am looked on as defending the RV business, BECAUSE, I DO KNOW what I am talking about and when nonsense is posted, I point it out. The whole point of this thread boils down to LOCAL contractors that have no knowledge of what they are doing. The OWNERS manuals of most RV's explain some of the detail of 30 and 50 amp service, but do not get into the nitty gritty, which the RV'er does not need to know and can readily find the info thru the internet. Doug

[MrWizard]

People never give the residential house breaker panel second thought unless renovating and older home, they don't move the stick and brick around they are not subject to changes of location and power

But people move their RV, and then come here and ask questions and are surprised by the answers
You and I know the old std is 3600 kva and the new one is 12000 kva
Big difference
Buyers are not really informed of the differences, or the relationship of use

And that is the failure of the RV industry

You are IN the service part, not the MFG part
I am not in the industry at all

Let's just agree to disagree, and you can quit trying to defend the industry short comings

[dougrainer]

chuggs wrote:

dougrainer wrote:

chuggs wrote:
It's simple folks.

50 amps is a limitation...the camper may draw up to 50 amps...at which point the circuit breaker will trip.

The thing that runs his fridge and air conditioning is Voltage (pressure)... So with the a/cand fridge turned on...measure the voltage in one of the campers outlets. If it's normal...then that's not the problem...there would be significant loss over the line if the wiring weren't capable... If the circuit breaker is tripping...you can use a clamp meter to measure and record the peak amps...or simply swap breakers to make sure you don't have a weak one. Anyway, if his coach is tripping the breaker I would check for normal voltage... When voltage is low...the amperage draw goes up so the load can get the required watts to function. If that's normal...then the load in his camper is too high... IE maybe his compressors are going bad and pulling too high a load.

Sorry, WRONG. 50 amp RV service is a TOTAL of 100 amps.
As to the "misinformation" the fault of the RV industry. WRONG again. The RV industry uses the NEC electrical code as its basis. Blaming incompetent Electricians on the RV industry is wrong. Doug

Your point is noted...but it's irrelevant. The camper is a 110v vehicle. When you connect it to 220v...you simply have two 110v buses. EACH bus individually should be wired to safely carry a 50 amp load... Saying that it's 100 amps total is irrelevant. That would be like going into your house and seeing a 200 amp main breaker...and then insisting that it's really 400 amps... I don't see why you would want to do that.

You cannot tell me a way to place a clamp meter on an RV service pole and measure 100 amps. You can measure up to 50 off of L1, and up to 50 off of L2... So you could say you have 110v x 50amp + 110v x 50 amp. Or you could say you have 220v x 50 amps...but it's all the same. If you can measure 100 amps...something is wrong with your wiring. Amps is current. When you want to add thing up to see energy draw...you're better off talking in KVA, watts, etc....

You cannot compare a 200 amp HOME panel with a RV panel. This is what YOU stated.

"50 amps is a limitation...the camper may draw up to 50 amps...at which point the circuit breaker will trip".

WRONG. The 50 amp RV will draw up to 100 amps total and IF (not really possible) you go OVER one of the 50 amp breaker limits, that breaker will trip. A 50 amp RV has the loads almost evenly divided between the 2- 50 amp lines to the RV. I measure EACH line with my clamp amp meter and then add for the total draw. Built in EMS RV systems also will show the voltage and sometimes the amp draw on EACH leg and then the TOTAL amp draw(both legs) the RV is pulling. Doug

[MrWizard]

dougrainer wrote:

chuggs wrote:
It's simple folks.

50 amps is a limitation...the camper may draw up to 50 amps...at which point the circuit breaker will trip.

The thing that runs his fridge and air conditioning is Voltage (pressure)... So with the a/cand fridge turned on...measure the voltage in one of the campers outlets. If it's normal...then that's not the problem...there would be significant loss over the line if the wiring weren't capable... If the circuit breaker is tripping...you can use a clamp meter to measure and record the peak amps...or simply swap breakers to make sure you don't have a weak one. Anyway, if his coach is tripping the breaker I would check for normal voltage... When voltage is low...the amperage draw goes up so the load can get the required watts to function. If that's normal...then the load in his camper is too high... IE maybe his compressors are going bad and pulling too high a load.

Sorry, WRONG. 50 amp RV service is a TOTAL of 100 amps.
As to the "misinformation" the fault of the RV industry. WRONG again. The RV industry uses the NEC electrical code as its basis. Blaming incompetent Electricians on the RV industry is wrong. Doug

Like you said 100 amps, two legs 50 amps each
When was the last time you heard a salesman, or a MFG tell a customer it's 100 amps of power , instead of the old std of 30 amps power

Unless specifically told people think 50amps at 120v
There is a great deal of confusion by the public aka consumers
The old 30 amp is configured and referred to like an outlet
Where the 50 amp is two legs like a residential service
NEC code is adhered too in doing the wiring
But the RV industry has never taken time to correctly inform the public
The 50 amp RV service can provide over three times the amount of power as the 30 amp service, most people don't understand that
They think it's only 20 amps more power used
They think if they leave one item turned off they can run on 30 amp adapter almost the same as when connected to the 50/100 service

So yes, I think the industry as whole is at fault for the buyer not knowing about his power usage and needs
A great many techs try too inform the user, but this is usually after the user has problems

[Tom_N]

I use a clamp on AMP meter.

-Tom, W3TLN

[wa8yxm]

Also, the O/P said the complainer simply said I CAN NOT USE. not why,, a bit of What happened would really help.. I will explain (And by the way I forgot one thing in my tester panel above.. VOLTAGE METERS you need two of those too, one for each side of the box)

First: If the Complainer had a "Surge Protector" Such as a Progressive Industries HW-50C and the outlet he plugged in was a long way from the distribution box, a long way to power.. And the electrician who wired it used the MINIMUM wire size for 50 amp.. Well the voltage drop when sucking major power could have shut him down.

The outlet would still check out as good on a straight voltage test

120-0-120
240---240


But.. with say a 40 amp load that 120 could become 110 or even 100 (And 100 will shut down an HW-50C)

THIS, is why I designed a test board up above.

As I said on each leg, put 4 space heaters (By building a proper test panel) and a volt meter, you should not see a significant voltage drop

Test both legs (you may test one at a time)

[93mastercraft]

Love it how everyone becomes an electrician. This was an interesting thread. We have a storage owner was trying to accommodate an RV owner. IMHO, when it comes to electricity, if you have any doubt what so ever what you are doing or if you don't understand how electricity works or think you know how electricity works, then your best bet is to hire a licensed Electrician to assess your situation.