Turning off breaker is dangerous?

[Richpatty]

I am glad I am not the only one who thinks this is odd. DW and I stood there for several seconds wondering if we were reading it wrong…

 

[Neal]

So let’s talk about arcing for a moment. When do you see arcing (spark) with plugs? When plugging in or removing a plug? Me? Always when plugging in. Never when removing that I can recall. And this is with 120V outlets. Breaker is off for me when dealing with the RV 50A.

 

[rvkev]

My procedure:

1. Open box and make sure the last person turned off all the circuits.
2. Make both the connections at the box and camper.
3. Turn on only the circuits that you are plugged into.
4.. Enjoy your stay

 

[GTS225]

So let’s talk about arcing for a moment. When do you see arcing (spark) with plugs? When plugging in or removing a plug? Me? Always when plugging in. Never when removing that I can recall. And this is with 120V outlets. Breaker is off for me when dealing with the RV 50A.

Actually, there's arcing at both moments.....you just may not see it.
Newton's law states that an object in motion tends to stay in motion unless acted on by outside forces. This applies to electrons in motion as well. If there's a load ready at the moment of contact in the plug/outlet interface, there'll be arcing, and the same goes if there's a load of any type at the moment of disengaging the plug/outlet interface. Even if that load is just the digital readout of your microwave, or the always ready convertor. The only practical way I can see to eliminate those small loads is to have a main breaker in the camper turned off. Even then, there's no guarantee something wasn't done to your unit before you got it, or there's a load not controlled by the main.

Just my 2-pence.....Roger

 

[GypsyR]

I have a 50 amp hookup at home where the RV lives and it stays plugged into it 24/7. One day when getting ready to leave I forgot to turn of the breaker before unplugging. I don't recall what I might have had running in the coach but there was an arc big enough to make me jump back. After that I was ALWAYS sure to turn off the breaker before connecting or disconnecting and that's what I do at campgrounds too. Period. Arcs like that are not healthy.

 

[Neal]

I've spent minutes hours days vetting the community to find the most knowledgeable electrician in the community to perform a test of arcing both insert and withdrawing a precise measuring device for a very important analytical purpose the entire RV community depends on. It seems the person to perform this test is clear, based on this post, and we are all eager for the results and video of course. Clodzapper - you are the man for the job!

 

[MemoriesByTheMile]

My experience (when not turning off the breaker)
- when plugging in I have never seen an arc or heard anything. This is because the power transfer switch in the rig does not transfer full power to the shore until a few seconds after plugging in the rig
- when unplugging I have never seen an arc as we always turn off all 120v items before unplugging from shore power (ac, floor heat, water heater, microwave, etc)
At home base we do NOT use the breaker for killing power but we do use a double pole switch that are designed to handle switching on / off.

 

[team bradfield]

we found some campgrounds out west had similar signage, they want you to leave the breakers on to keep the spigots from freezing (wrapped and plugged in) we always make sure to turn them back on after unplugging, they are on the 20amp circuit but I guess some turn them all off out of habit?

 

[Texas Clodhopper]

I've spent minutes hours days vetting the community to find the most knowledgeable electrician in the community to perform a test of arcing both insert and withdrawing a precise measuring device for a very important analytical purpose the entire RV community depends on. It seems the person to perform this test is clear, based on this post, and we are all eager for the results and video of course. Clodzapper - you are the man for the job!

I love it. Please change my official "who am I known as" from Texas Clodhopper to Clodzapper. It's an electrifying moniker.

 

[Mighty_J]

I’ve always shut them off before plugging in as well, but I get the comment about the pipe heaters. On this new to us coach, it’s got a manual shore shut-off switch in the driver’s first bay, so my plan is to switch that off, plug the watchdog to the energized pedestal plug, if I’ve got good power, plug the shore cord into the watchdog and then flip the shore switch. Unplugging I’ll just flip the shore switch off and leave it off until the next campground. At first I thought it was gonna be annoying, but the idea of the manual switch is growing on me.

 

[Jim]

I love it. Please change my official "who am I known as" from Texas Clodhopper to Clodzapper. It's an electrifying moniker.

Oh lord. . .

The name’s got spark, style, and a jolt of personality. Consider your electrifying moniker officially updated.

 

[GlampDaddy]

NIRVC's valets all have instructions to plug-in coaches when they park them. They usually do, but they NEVER check to see if the breaker is on. If all breakers are on all the time, the coaches are more likely to have power...so the customers' batteries don't die and the company will have to replace fewer of them.

 

[GlampDaddy]

I love it. Please change my official "who am I known as" from Texas Clodhopper to Clodzapper. It's an electrifying moniker.

...good for cow patties, too!

 

[Richpatty]

So the general consensus on this thread and the “other one” seem that although they could see why NIRVC would want to leave them on for some random reasons, it really is not best practice. And although they may save their breakers, they may ruin the outlets….

 

[MemoriesByTheMile]

As an analyst who likes to understand the “why” …

It may be general consensus - but tradition (we’ve always done it this way) plays a very strong role in these types of discussions.

There are other ways to mitigate any electrical arcing when unplugging besides turning off the breaker and these other ways are better protection for items such as A/C units.

 

[Chuggs]

Two things I do every time.

1) Breaker OFF for making or breaking the connection.

2) No power on the line when repositioning the cord reel.

It’s a race…wear out a breaker or wear out a receptacle.

The receptacle wearing out ruins plugs. The resistance cause plugs to melt. Replacement cords for your coach are $$$.

No mater how many signs they post…valets are still going to screw up and ruin batteries. Just because you are plugged in and breaker ON…there are still a lot of ways the batteries could not be charging. Signs are not a replacement for education. Try a checklist…

 

[Texas Clodhopper]

As an analyst who likes to understand the “why” …

It may be general consensus - but tradition (we’ve always done it this way) plays a very strong role in these types of discussions.

There are other ways to mitigate any electrical arcing when unplugging besides turning off the breaker and these other ways are better protection for items such as A/C units.

I'm interested in learning about these "other ways".

 

[Chuggs]

IDK

For one…the Air Conditioner has a timer to prevent short cycling the compressor…it also staggers startup of multiple units.

So, that said… there are RVs that do not have an ATS. We do…so, I guess some feel there isn’t a demand until the connection is made and the ATS relay closes… and others may have a surge protector or watchdog, to delay further the load being applied until the wiring and acceptable power is detected. And then…if you wanted to go thru the hassle…tripping the main inside your distribution panel could remove all loads.

I guess it can be overthinked. Just my opinion…if you use the breaker, you are safe regardless of the rv. In rigs like ours with transfer switches, etc…the arcing probability is most likely going to be when unplugging. Most of us don’t run around and turn off the charger, or make sure the inverter isn’t in pass thru mode powering the residential fridge, etc…. I certainly don’t trip the main breaker. Using the pedastle Is one stop shop…and wear and tear is directed to an easily accessed and low cost item.

I would think everyone has seen the spark when you are vacuuming the carpet and reach the end of the cord. The plug comes out while the vacuum is drawing a substantial load. Normally, we plug and unplug appliances with the power switch OFF…so it is a non event.

I haven’t seen it first hand…but our ground crews hated when pilots gave them the signal to remove ground power, and haven’t switched over to APU first. I have heard the arc can shoot out 4-6 “… I’m sure that would get my attention. With galleys, lights, avionics, lighting, entertainment, etc…there is a significant load on the ground power, if it is carelessly left selected.

 

[Texas Clodhopper]

Sign or no sign, I will continue to turn the breaker on and off when I'm connecting or disconnecting. I have enough to remember to do when arriving or leaving and making sure everything is turned off on my end will only add to the list.

 

[Kevin D Pem]

IDK

For one…the Air Conditioner has a timer to prevent short cycling the compressor…it also staggers startup of multiple units.

So, that said… there are RVs that do not have an ATS. We do…so, I guess some feel there isn’t a demand until the connection is made and the ATS relay closes… and others may have a surge protector or watchdog, to delay further the load being applied until the wiring and acceptable power is detected. And then…if you wanted to go thru the hassle…tripping the main inside your distribution panel could remove all loads.

I guess it can be overthinked. Just my opinion…if you use the breaker, you are safe regardless of the rv. In rigs like ours with transfer switches, etc…the arcing probability is most likely going to be when unplugging. Most of us don’t run around and turn off the charger, or make sure the inverter isn’t in pass thru mode powering the residential fridge, etc…. I certainly don’t trip the main breaker. Using the pedastle Is one stop shop…and wear and tear is directed to an easily accessed and low cost item.

I would think everyone has seen the spark when you are vacuuming the carpet and reach the end of the cord. The plug comes out while the vacuum is drawing a substantial load. Normally, we plug and unplug appliances with the power switch OFF…so it is a non event.

I haven’t seen it first hand…but our ground crews hated when pilots gave them the signal to remove ground power, and haven’t switched over to APU first. I have heard the arc can shoot out 4-6 “… I’m sure that would get my attention. With galleys, lights, avionics, lighting, entertainment, etc…there is a significant load on the ground power, if it is carelessly left selected.

As an added note.

Breakers/fuses/switches/relays, are designed with an air gap based on voltage. That gap is large enough to guarantee that an ark will discontinue. The contacts are of material and size that offers a reasonable life expectancy. And as chuggs has stated, the contacts in your plug are not designed to handle the ark when unplugging/plugging.

The solution is obvious!