Another 50A plug melted

[cavie]

Originally Posted by sourdough

I think you're confusing the issue and probably the OP. The highlighted above is untrue. I've discussed RV receptacles with electricians (not "retired" electricians) and none of them ever said 100 amps was not available to the RV....none; in fact the opposite. Whether you can have 100amps in aggregate or 50A on 2 separate legs, the RV has the ability to pull up to 100A....not on one leg....from the RV service as a whole (both legs). To continually say there is only 50A available is just not correct.

An EMS monitors what's coming to it from "upstream", not downstream (behind it). When the incoming (upstream) power has any of the faults it monitors for it shuts down. If you have something defective in the trailer (downstream/behind it) causing havoc....it does not know. The new Southwire Surge Guard does monitor "downstream" (back toward the trailer) for a couple of faults but it's the only one I am aware of.

My bad. Your second paragraph is correct. I said it wrong. Your first paragraph had me going I stand by the first one. 50 amps will trip it and you will have no amps available. That's what confuses the newbies. All they remember is "100 amps available". Electricians do not talk about Total amps across a 240-volt breaker. The same goes for the Mega Yachts that do in fact use 240 inside the RV. One leg goes over 50 amps a BOOM you have no amp available so why talk about it?

I sorry you do not believe in Retired Electricians or Retired Building inspectors. Maybe this site needs a disclaimer? Probably just got thrown off this site.

[wiredgeorge]

Originally Posted by sourdough

I think you're confusing the issue and probably the OP. The highlighted above is untrue. I've discussed RV receptacles with electricians (not "retired" electricians) and none of them ever said 100 amps was not available to the RV....none; in fact the opposite. Whether you can have 100amps in aggregate or 50A on 2 separate legs, the RV has the ability to pull up to 100A....not on one leg....from the RV service as a whole (both legs). To continually say there is only 50A available is just not correct.

An EMS monitors what's coming to it from "upstream", not downstream (behind it). When the incoming (upstream) power has any of the faults it monitors for it shuts down. If you have something defective in the trailer (downstream/behind it) causing havoc....it does not know. The new Southwire Surge Guard does monitor "downstream" (back toward the trailer) for a couple of faults but it's the only one I am aware of.

Could you give some detail of faults the Southwire monitors inside the trailer and I guess protects in some fashion? If these faults are detected, does the Southwire shut down incoming power?

[flybouy]

I've been looking on Southwire's site and I can't find any claims of any detection or protection available beyond the EMS. That doesn't mean it doesn't exist but I'd like to see where that claim comes from myself.

[sourdough]

Originally Posted by flybouy

I've been looking on Southwire's site and I can't find any claims of any detection or protection available beyond the EMS. That doesn't mean it doesn't exist but I'd like to see where that claim comes from myself.

Here's a link;

https://rvpower.southwire.com/produc...a-model-34951/

3rd bullet under "protects against". Open neutral line AND load side.

[sourdough]

Originally Posted by cavie

My bad. Your second paragraph is correct. I said it wrong. Your first paragraph had me going I stand by the first one. 50 amps will trip it and you will have no amps available. That's what confuses the newbies. All they remember is "100 amps available". Electricians do not talk about Total amps across a 240-volt breaker. The same goes for the Mega Yachts that do in fact use 240 inside the RV. One leg goes over 50 amps a BOOM you have no amp available so why talk about it?

I sorry you do not believe in Retired Electricians or Retired Building inspectors. Maybe this site needs a disclaimer? Probably just got thrown off this site.

No need to be thrown off. It's a matter of terminology and what's being discussed. If asked what will trip the breaker to a 50A RV the answer is obviously anything exceeding 50A on one leg. If however one is discussing total power available in the RV it matters not that ONE leg will trip if exceeding 50A. If neither does, which they shouldn't, you have 100A available for use in the RV. Nothing more than trying to describe the same service from 2 different perspectives - both right.

I think when new folks are trying to figure out a new RV with 50A service and never had it before they need to know what they actually have - what is available in that RV total, not what will trip one leg. If the question arises of why it's called 50A your explanation would then be the answer.

[sourdough]

Originally Posted by sourdough

Here's a link;

https://rvpower.southwire.com/produc...a-model-34951/

3rd bullet under "protects against". Open neutral line AND load side.

Edit: George the above feature may have helped your relatives in their situation if I understand it correctly.

[flybouy]

Originally Posted by sourdough

Here's a link;

https://rvpower.southwire.com/produc...a-model-34951/

3rd bullet under "protects against". Open neutral line AND load side.

Thanks, I didn't open the link to each device and didn't see any other references.

[sourdough]

They touted the feature a while back but haven't come across it much since. I am looking at getting the newer model because it has a remote which would be beneficial for my application. I believe that is the only model that offers it.

[wiredgeorge]

Originally Posted by sourdough

Here's a link;

https://rvpower.southwire.com/produc...a-model-34951/

3rd bullet under "protects against". Open neutral line AND load side.

It said "Open neutral – line and load side". Guess I don't understand what this means. Open neutral... wouldn't that mean the ped power had no neutral and thus any EMS would shut down the power at the ped? Just trying to understand as I can't see how an open neutral in some wire in the trailer could be detected.

[wiredgeorge]

Hey... I retired from the Federal Government in 1998. Since some (if not most) government employees are partially brain dead, would that make me a RETIRED IDIOT? I bet they have my computer monitor in some museum since it had an outline of solitaire cards burned into the green CRT! I was darn good at solitaire!

[CedarCreekWoody]

Originally Posted by wiredgeorge

It said "Open neutral – line and load side". Guess I don't understand what this means. Open neutral... wouldn't that mean the ped power had no neutral and thus any EMS would shut down the power at the ped? Just trying to understand as I can't see how an open neutral in some wire in the trailer could be detected.

I'm with you George, any EMS would detect an open neutral on an incoming line and I've never known any that could detect that on a downstream circuit.

[bobbecky]

I believe the ability to sense an open neutral on either side of the EMS is because the device is looking for current return on that neutral, and if the neutral is open and there is no current return, the unit shuts things down. An open neutral is about one of the most damaging things that can occur because the hotleg voltage is not stable without the neutral and can greatly exceed the 120-125 volts that is expected.

[flybouy]

Completly off topic but in the late 80's early 90's I worked for a retailer (Meery-Go-Round Enterprises) and I ran facilities and the guy in the office next to me ran the construction side. he was a real arrogant snobh and was always playing solitare. I went over to my departments cubicals where about a dozen of myfolks worked and found an unused competer. I fired up Solitare and cranked up the RT to full bright and let it set for about 5 weeks. It burned in a nice image. Then I swapped it out for his monitor only I bent a pin in the video cable so it wouldn't work. He fired it up the next morning and ccalled the IT guys because his monitor didn't work. They replaced it but the next day they removed the Solitare game from his computer.

Knowing I was a compurter geek he asked me if I could load it bak onto his computer. I did, with pleasure. I created a little .bat file that loaded the game AND sent a console message to myself and few of my team a message that read "Stanley's playing solitare again!". As he would play several times a day itbecame quiye comical to hear folks laughing across the hall every time the message flashed on the screen.

[sourdough]

Originally Posted by bobbecky

I believe the ability to sense an open neutral on either side of the EMS is because the device is looking for current return on that neutral, and if the neutral is open and there is no current return, the unit shuts things down. An open neutral is about one of the most damaging things that can occur because the hotleg voltage is not stable without the neutral and can greatly exceed the 120-125 volts that is expected.

^^^I believe this is correct. When that voltage is gone it shuts off.

[rhagfo]

Well my preference is hard wired and Progressive EMS, fully self contained. What I mean by that is that the hard wired unit has cable clamps that secure the cable to the unit, Southwire requires that the cable be secured within 7” of the unit.

[Hellbilly13]

Originally Posted by CedarCreekWoody

Bill if you are considering a portable EMS be sure it is a true EMS that will shut down the power if needed. Many of them are simply surge protectors. As Marshall points out there are pros and cons to either type. My personal preference is the permanently mounted type, I was just pointing out why some recommend the portable.

I do have a true ems; my research back then at least revealed that requirement. I have a Progressive Industries EMS-HW50C.

[Hellbilly13]

Originally Posted by sourdough

I think you're confusing the issue and probably the OP. The highlighted above is untrue. I've discussed RV receptacles with electricians (not "retired" electricians) and none of them ever said 100 amps was not available to the RV....none; in fact the opposite. Whether you can have 100amps in aggregate or 50A on 2 separate legs, the RV has the ability to pull up to 100A....not on one leg....from the RV service as a whole (both legs). To continually say there is only 50A available is just not correct.

An EMS monitors what's coming to it from "upstream", not downstream (behind it). When the incoming (upstream) power has any of the faults it monitors for it shuts down. If you have something defective in the trailer (downstream/behind it) causing havoc....it does not know. The new Southwire Surge Guard does monitor "downstream" (back toward the trailer) for a couple of faults but it's the only one I am aware of.

I am confused, but not about about the first part. I do understand that if I go over 50A on one leg the breaker will kick off. The park employee that was arguing with me went over and pointed at the breaker in the pedestal and said "it says right here on the breaker that it's only 50 amps". He didn't understand that it was actually two 50 amp breakers ganged together.

The second highlighted part is what has caused my confusion. My original question was how to prevent the loose connection from causing a fire in the future. From what you are saying here, adding a pedestal mounted ems will not add any protection for me in this regard. The reasoning of the guy at the parts store that the ped ems would better protect my rig was wrong since it doesn't look at what's going on back at the rig. Now I'm thinking that my onboard ems actually has a better chance of catching what happened to me. And now that I look back on the sequence of events, it was probably warning me that we had a loose connection by kicking off repeatedly until the connection fused together inside the plug. At that point everything was cool until our amp demand got too high and the fused connection starting overheating. Does that sound logical?

[JRTJH]

Here's one of the FAQ statements from the Progressive Industries website:

Q: Is there a difference in protection between the different EMS models?
A: No. All EMS's offer the same protection.

It's been a "boatload of years" since I taught electronics and crawled in the holes in the ground where ICBM's were kept ready to send a "boatload of atoms" around the globe.... But, I don't believe anyone has "retrained electrons" to alter their behavior.....

An electronic circuit is the COMPLETE circuit, not a "fraction that can be divided into "before or after" a specific device. Terms like "input power" or "return neutral" are used to denote the location, not to denote the function... It takes an ENTIRE electrical circuit, from the generating plant to ground for the system to function....

Most of us are concerned with the part of the circuit "from the campground pedestal, THROUGH the RV and back to the campground pedestal... Whether the EMS is installed "at the pedestal" or "at the power center" it performs the same function... The "instantaneous disruption" of power when a condition is detected occurs throughout the entire system without regard to "where in the system the EMS is located"......

Now, if electricity were a "one way distribution system" (like a water hose) the location of the shutoff valve would be important. In a "two way distribution system, any disruption at any location stops the entire distribution (provided there is no "alternate ground to conduct the electricity).

Unless you have "an alternate neutral or an extra ground" that can carry the power "around the shore power cord, when the EMS (with no regard to its location) shuts down power, then power "into the RV" and power "out of the RV" are both interrupted.....

So, I believe the statement from PI concerning their EMS models is true:

A: No. All EMS's offer the same protection.

[flybouy]

Originally Posted by Hellbilly13

I am confused, but not about about the first part. I do understand that if I go over 50A on one leg the breaker will kick off. The park employee that was arguing with me went over and pointed at the breaker in the pedestal and said "it says right here on the breaker that it's only 50 amps". He didn't understand that it was actually two 50 amp breakers ganged together.

The second highlighted part is what has caused my confusion. My original question was how to prevent the loose connection from causing a fire in the future. From what you are saying here, adding a pedestal mounted ems will not add any protection for me in this regard. The reasoning of the guy at the parts store that the ped ems would better protect my rig was wrong since it doesn't look at what's going on back at the rig. Now I'm thinking that my onboard ems actually has a better chance of catching what happened to me. And now that I look back on the sequence of events, it was probably warning me that we had a loose connection by kicking off repeatedly until the connection fused together inside the plug. At that point everything was cool until our amp demand got too high and the fused connection starting overheating. Does that sound logical?

They only way to prevent this from occurring again is preventative maintenance and monitoring the connections.

Preventative maintenance ... check the accessible connections such as the wire connections inside the camper.

The monitoring the connections ... Make certain when plugging into the pedestal and side of the camper that the plugs fit with "positive" force and do not feel loose. If you feel ANY heat in ANY plug or receptacle investigate WHY. Visually inspect the plug connections EVERY time you connect or disconnect for signs of heat or carbon tracing on the connectors.

As far as I am aware, there are no devices that will monitor this for you. By the time the EMS or circuit breaker has interupted the power due to an issue with the cable and connections the those connections have become sever and require immediate attention.

[Hellbilly13]

Originally Posted by JRTJH

Here's one of the FAQ statements from the Progressive Industries website:

Q: Is there a difference in protection between the different EMS models?
A: No. All EMS's offer the same protection.

It's been a "boatload of years" since I taught electronics and crawled in the holes in the ground where ICBM's were kept ready to send a "boatload of atoms" around the globe.... But, I don't believe anyone has "retrained electrons" to alter their behavior.....

An electronic circuit is the COMPLETE circuit, not a "fraction that can be divided into "before or after" a specific device. Terms like "input power" or "return neutral" are used to denote the location, not to denote the function... It takes an ENTIRE electrical circuit, from the generating plant to ground for the system to function....

Most of us are concerned with the part of the circuit "from the campground pedestal, THROUGH the RV and back to the campground pedestal... Whether the EMS is installed "at the pedestal" or "at the power center" it performs the same function... The "instantaneous disruption" of power when a condition is detected occurs throughout the entire system without regard to "where in the system the EMS is located"......

Now, if electricity were a "one way distribution system" (like a water hose) the location of the shutoff valve would be important. In a "two way distribution system, any disruption at any location stops the entire distribution (provided there is no "alternate ground to conduct the electricity).

Unless you have "an alternate neutral or an extra ground" that can carry the power "around the shore power cord, when the EMS (with no regard to its location) shuts down power, then power "into the RV" and power "out of the RV" are both interrupted.....

So, I believe the statement from PI concerning their EMS models is true:

A: No. All EMS's offer the same protection.

This was my original line of thinking. Up until my issue happened, I "knew" how the shore power worked in my rig along with the ems. This whole thing caused a lot of confusion for me and has me questioning things I have "known" for decades.


I actually worked as an Electronics Engineer for a while. Nowadays, I only have the degree and the longer I go without using it the less I "know" or remember about how electricity works. That may sound strange, but my long-term memory is terrible.