30 AMP or 50 AMP connection.

[Boudreaux]

We have the '16 Greyhawk MV with 30 amp service. In a conversation with an electrician, he stated that using 30 amp service will not give you a full 30 amps of power. He stated that same goes for 50 amp service.

That set me to thinking. So, I'm wondering. [B]If prepared with a 50 to 30 amp dog bone, would it be beneficial to use the 50 amp service and plug the coach to the 30 amp side of the dog bone? Would that give me a total 30 amps of power or am I just wasting my time?[/B]

Reaching out to those with experience ......

[curver900]

is your question if you plug into a 50amp service will you get a true 30amp circuit? if your trailer is 30amp and you plug it into a 50amp dog bone you will only be able to use 30amps in your trailer.. regardless..

if you plug into a 20amp at your house receptacle you get 20amps that makes sense too.. It would be no different to than to think about your house.. 100amp service in.. each fuse is rated to a certain 10/15/20 etc.. amp rating you cannot exceed that or it will pop.. same with your camper you have 50 amps to it but you can only leverage 30amps due to the main breaker..

Your amperage can be measured with a voltmeter.. that will tell you what the current is coming in ... if it is a 30amp ckt you are likely getting 30 amps plus or minus a percentage... and EMS unit will be your friend if the voltage or current get to far out of whack...

[Force]

Perhaps all he meant was that a 30 AMP will trip once it hits 80% load on a sustained basis? (thus never quite giving you the full 30 AMP)

That wouldn't change going to a 50 AMP since a 30 AMP only uses 1 hot leg at 110V anyway so you're getting the same thing (a 50 AMP run is typically 2 hot legs to get you 220V)

[ROC-REQS]

It won't make a different.

50A shore power provides power via 2 legs.

30A shore power provides power via only 1 leg.

A 50A to 30A dog bone only used 1 leg of the 2 50A legs.

So, if you connect directly to the 30A shore power or connect to the 50A shore power using a 50A to 30A dog bone, your provably getting power off the same leg.

I'm curious on why the electrician said you wouldn't get a full 30A.

[Force]

He's correct, the circuit will trip before you hit 100% based on my understanding of how breakers work. (I frequently stay at the Holiday Inn Express)

[Boudreaux]

Thanks to all ..... I'll drop the dog bone issue...

[33 RLDS]

Dog bone still not a bad idea to have on hand as many 30 amp plugs in campgrounds are worn as they get used much more than 50 amp.

[Force]

Originally Posted by 33 RLDS

Dog bone still not a bad idea to have on hand as many 30 amp plugs in campgrounds are worn as they get used much more than 50 amp.

X2

We camped one time in 90+ degrees and everyone on the 30A feed in our row was tripping the breaker. I was the only one that was able to use the 50A instead and keep the AC running

[hoppers4]

I always use the 50A dogbone if available. Those plugs are generally in better condition and the breaker on the post won't trip. There's actually two legs of 50A available but you're only using 1 leg with the dogbone. If I inadvertently draw more than 30A, the house breaker will trip.

[Crossingover]

Originally Posted by hoppers4

I always use the 50A dogbone if available. Those plugs are generally in better condition and the breaker on the post won't trip. There's actually two legs of 50A available but you're only using 1 leg with the dogbone. If I inadvertently draw more than 30A, the house breaker will trip.

There goes the neighborhood! All you 30-ampers wearing out the 50-ampers receptacles [emoji366] just for a better connection.


Sent from my iPhone using Tapatalk

[curver900]

Originally Posted by Boudreaux

Thanks to all ..... I'll drop the dog bone issue...

you would still need one if you go to a place that has 50amp service to get 30amp service. You still need to convert from the 50amp plug to a 30amp plug..

[Mustang65]

Originally Posted by Force

X2

We camped one time in 90+ degrees and everyone on the 30A feed in our row was tripping the breaker. I was the only one that was able to use the 50A instead and keep the AC running

As you do, we always use the 50Amp outlet, well anyway I do as DW has yet to plug in the service cable. There are to many old worn-out 30 amp receptacles.

My concern would be, if everyone was tripping breakers, what was the line voltage, and that combination (lower line voltage/high amp load) may be the issue for the tripping breakers? Could cause problems with the AC compressor. Have yet to hit the voltage issue.

I have the AC Digital Voltage Display below and leave it plugged in by the kitchen sink.

Don

My Registry

RVing with SOLAR

[Force]

Sorry, that wasn't terribly clear as written.

What I meant was the combined load of all the campers plugged into that particular feed was tripping the campground circuit breaker handling that feed, so just straight up overloaded with all the AC's cranking away.

[Boudreaux]

Originally Posted by curver900

you would still need one if you go to a place that has 50amp service to get 30amp service. You still need to convert from the 50amp plug to a 30amp plug.

Oh.... I have that stuff. The first thing I purchased (Dixie RV gave us $75 credit in their store) back in Feb '16 was extra 30 amp cords, water hose (25' & 15') 50 to 30 dog bone, 110 to 30 dog bone, Premium Sewer hoses.

Thus far, I have not lacked in anything while traveling. Thanks for all the info.

[chfraser01]

One thing to keep in mind, your cord from the RV is only rated to 30 amps, so when you plug into the 50 amp plug with your 30 amp cord, you lose some protection for your cord. Everything else downstream is protected by its own breaker.

[Les7h]

You won't miss the 2-3 amps that will cause the breaker to trip - whoever told you that is 100% correct about a " non issue " that will not cause you any problems Les

[Jagiven]

Originally Posted by ROC-REQS

It won't make a different.

50A shore power provides power via 2 legs.

30A shore power provides power via only 1 leg..

With the 50 amp, 2 leg service, you actually have a 100 amps total service, 50 amps per leg. With the 30 amp sm 1 leg service, you only have a total service of 30 amps.

Originally Posted by chfraser01

One thing to keep in mind, your cord from the RV is only rated to 30 amps, so when you plug into the 50 amp plug with your 30 amp cord, you lose some protection for your cord. Everything else downstream is protected by its own breaker.

This is way I try not to use the 50 amp plug.

For example if the cord got damaged, such as pinched, you could pull more than 30 amps, through the cord, as the damaged area will produce a lot of resistance, aka heat, which in turn could start a fire, as the cord is not rated for that must power draw.

[RayBo]

Originally Posted by chfraser01

One thing to keep in mind, your cord from the RV is only rated to 30 amps, so when you plug into the 50 amp plug with your 30 amp cord, you lose some protection for your cord. Everything else downstream is protected by its own breaker.

So, a constructive comment on this theory to try to help everyone understand a little more. The breaker protects the wiring and the devices. If you have a 30amp main breaker, the device (your RV) cannot draw more than 30 amps, so your cable is protected. Amperage from a 50A pedestal does not run down the wire and stop at your main breaker (think of water against a dam and then understand that electricity does not work exactly that way.)

The power is drawn by the device (your RV) as required. There's not 50A of power sitting there cooking your cable when it's not being demanded by your device. So, the thought about "losing some protection for your cord" should be further considered and then dismissed. You can't really draw more than 30A (from a 50A outlet, or even a 1000A outlet for that matter) if your main breaker is 30A. Once you draw about 85-90% of the amperage (or so, manufacturers differ) you will trip the main and stop the flow of current.

If that were not the case, there would be no such thing as dogbones to get you from 50 to 30 or even 15, because every one of us would then be starting fires. If you plug your 120v appliance directly to a pedestal using a 15F to 50M dogbone (I have one) and all 50A (100A if both legs used) was somehow "backed up" in the cord, you would then immediately burn up the cord and the appliance. However, this does not happen because the appliance only draws the current it needs and therefore the wire is not burdened with all the amperage available on the outlet on the pedestal.

Think of electricity like you think of plumbing.

Voltage is measured in volts, current is measured in amps and resistance is measured in ohms.

An analogy to help understand thinking about plumbing pipes. The voltage is similar to the water pressure, the current is similar to the flow rate, and the resistance is like the pipe size.

Look here for a lot more detail than you probably want.
Water circuit analogy to electric circuit
http://hyperphysics.phy-astr.gsu.edu...atcir2.html#c1

In any case, the only time wire sizes come into play is when the current (AMP flow) is greater than the wire's rated size. I can hook my cell phone charger to a 1000A supply, but it's only going to draw 2.1A, so my wire is safe.

[hoppers4]

Originally Posted by chfraser01

One thing to keep in mind, your cord from the RV is only rated to 30 amps, so when you plug into the 50 amp plug with your 30 amp cord, you lose some protection for your cord. Everything else downstream is protected by its own breaker.

X2. However, for me the risk is too small to be a concern.

[bedrck46]

Originally Posted by curver900

Your amperage can be measured with a voltmeter.. that will tell you what the current is coming in ... if it is a 30amp ckt you are likely getting 30 amps plus or minus a percentage... and EMS unit will be your friend if the voltage or current get to far out of whack...

Just curious as to how you can measure amperage with a volt meter??

You can read amps with a amp meter(clamp on style) But doesn't a volt meter only read VOLTS.