Quick question about hooking up to 50A when you get there

[JMCherry]

This is the same procedure we use:

But we include a surge protector when connecting to the pedestal. This runs a diagnostic test on the pedestal to make sure it’s working correctly. It’s has saved us a few times from bad pedestals.

Turn off the air conditioning unit.
Stop generator
Ensure pedistal breaker is turned off
Connect shore power cable to pedistal
Turn on pedistal breaker
Turn on air conditioning

[ptw]

Originally Posted by mjq1987

This contact arcing can cause pitting, discoloration, scorching or melting on the metal surfaces on the plug and/or receptacle. This damage may be minor, but eventually it could lead to a high resistance connection which leads to excessive heat generation which can lead to additional component damage and fires.

I agree.

If your cord is shorted or you have a problem on your coach, you may get burnt when plugging into the outlet with the breaker on. Always safer to turn on the power with the breaker.

A big reason for campground outlets going bad is people plugging into them without turning them off. As mentioned, the arcing will also damage your plug over time.

Another good practice is to adjust the length of your cord before turning the power on at the pedestal. I always plugged in, turned the power on, then adjusted the length of the cord on the reel and closed the bay door, before someone showed a picture of the contacts on the cord reel. The contacts are not good quality carbon brush contacts that are normally used on cable reels. The contacts are just spring metal and will cause pitting on the cable reel if turning the reel with power turned on.

[roblaura]

Similar to other comments, we do the following when the coach is parked and ready for set-up:

1.Shut off the AC units at the thermostat
2.When the AC units cease operating, shut off the generator
3. Connect coach to post electric (breaker off, connect cable, breaker on)
4, Turn the AC units back on.

All of this only takes a few minutes.

[jpuckett001]

Oh my gosh. Someone told you to do this? Was this a someone who sells new units to replace yours?

1. Always shut the a/c units down. It won't get too hot too quickly you should have 10 or so minutes of residual cool. Let your generator run for 3 minutes with minimal load to cool cylinders before shutting it down.

You can be using this time to level and pushing slides out etc etc.

2. After 3 min Shut down generators. Then plug in power. Turn A/C back on, etc.

[LHRanch]

Originally Posted by mjq1987

the most likely result in our low voltage scenarios is potential physical damage to the metal surfaces that the arc forms between. This contact arcing can cause pitting, discoloration, scorching or melting on the metal surfaces on the plug and/or receptacle. This damage may be minor, but eventually it could lead to a high resistance connection which leads to excessive heat generation which can lead to additional component damage and fires.

It's worth noting that you can develop this problem at other times than plugging and unplugging, if you overextend your cord, have kids tripping over it, etc. such that it gradually extracts itself from the outlet. We had this situation a couple months ago, melted both the outlet and the end of the RV cord, both had to be replaced.

[Piros1]

Originally Posted by mjq1987

Arc flash is the conduction of electricity across a high resistance medium. The term is usually reserved for high voltage situations where huge amounts of current can be generated during the event.

In our case, for 30A or 50A power connections, what happens when a breaker shuts or opens or a power plug under load is removed or plugged in, is that a brief arcing can occur between the load contact (plug) and the supply contact (receptacle) of the circuit. Unless you have contact with the arc or are surrounded by a flammable environment when it happens, the most likely result in our low voltage scenarios is potential physical damage to the metal surfaces that the arc forms between. This contact arcing can cause pitting, discoloration, scorching or melting on the metal surfaces on the plug and/or receptacle. This damage may be minor, but eventually it could lead to a high resistance connection which leads to excessive heat generation which can lead to additional component damage and fires.

Most breakers are quick acting to minimize arcing and some breakers have arc fault detection and tripping (not on our RVs). The quick acting contact movement minimizes arcing and contact damage, but it still happens and breakers do wear out over time.

Minimizing arcing is the reason why it's always best, under any electrical scenario regardless of the voltage and current involved, to connect/disconnect circuits and loads when they are not operating. The arc you get on a breaker that is shut/open with no/minimal load applied is less than what you get when you shut/open it under load.

This is a very definitive and clear answer, I guess I should of been more definitive. I hate to see folks have problems that are preventable. As you stated odds are you are not going to be hurt by the flash but I have seen equipment plugs/receptacles ruined from being unplugged under load. F FF own the if repetitively doing this will eventually cause issues.

[Piros1]

Originally Posted by ptw

I agree.

If your cord is shorted or you have a problem on your coach, you may get burnt when plugging into the outlet with the breaker on. Always safer to turn on the power with the breaker.

A big reason for campground outlets going bad is people plugging into them without turning them off. As mentioned, the arcing will also damage your plug over time.

Another good practice is to adjust the length of your cord before turning the power on at the pedestal. I always plugged in, turned the power on, then adjusted the length of the cord on the reel and closed the bay door, before someone showed a picture of the contacts on the cord reel. The contacts are not good quality carbon brush contacts that are normally used on cable reels. The contacts are just spring metal and will cause pitting on the cable reel if turning the reel with power turned on.

I had to bypass my cord reel on my new to me coach due to this exact problem. I assume the previous owner must have been doing what you are referring to. When I returned home with the coach I disassembled the reel and discovered the contacts were burned up from arcing. My replacement will be the type that does not use contacts, it spools the cord in a storage tube like I have on my Country Coach.

[mahdi]

Just an update to my last post. Service center found ground wire loose at transfer case and tightened all connections. Will check things out when we go on it next time.


Mahdi & Debbie
2019 Dutch Star 4018
2020 Tahoe LT

[tommar]

Originally Posted by mahdi

Just an update to my last post. Service center found ground wire loose at transfer case and tightened all connections. Will check things out when we go on it next time.


Mahdi & Debbie
2019 Dutch Star 4018
2020 Tahoe LT

Guess you are referring to your post #22 on page 2? So what transfer case? And exactly what problem did this solve?

[96 Wideglide]

Originally Posted by Piros1

First never plug or unplug your power cord into the power pedestal without turning the supply breaker off first. You can arc flash and this is an unsafe procedure and can be very dangerous.

I've stayed at many parks where you don't get the breaker on the pedestal.

Owner has a breaker room for the park.

[Piros1]

Originally Posted by 96 Wideglide

I've stayed at many parks where you don't get the breaker on the pedestal.

Owner has a breaker room for the park.

You can turn the main off in your RV and essentially do the same as shutting power at the pedestal. This would be the option if you there is no shut off at the pedestal not the preferred method but better than plugging it in under load. As stated earlier plugging in under load will create arcing on the plug and receptacle causing bad connections and creating excessive heat that can melt the insulation on the wires and plug.

[FL420]

Originally Posted by Piros1

You can turn the main off in your RV and essentially do the same as shutting power at the pedestal. This would be the option if you there is no shut off at the pedestal not the preferred method but better than plugging it in under load. As stated earlier plugging in under load will create arcing on the plug and receptacle causing bad connections and creating excessive heat that can melt the insulation on the wires and plug.

Now why didn't I think of that??[emoji848]
Thx for the tip!
[emoji40]

[mahdi]

Sorry Tommar. I meant to say transfer switch not transfer case. Yes I was referring to my post about no power when connecting to CG after generator was turned off.


Senior moment.



Mahdi & Debbie
2019 Dutch Star 4018
2020 Tahoe LT

[texskeet]

You know that a breaker is not designed to be a switch. When it is used as a switch its life is cut very short. I plug in hot, just like everything in my S&B.