30A vs 50A

cbr46 wrote:
A 50A circuit is actually 2 120V lines so I would guess they are 25A each. If true the breakers on the campground panel box should reflect this.


- bob

Really hate to see guesses on electrical issues. BTW, your guess is incorrect.

50 amp is TWO 50 amp circuits. Just look at the two pinned 50 amp breakers on any proper CG outlet.

Bottom line....with 30AMP just use 1 a/c unit at a time. No technical engineering degree needed.

cbr46 wrote:
A 50A circuit is actually 2 120V lines so I would guess they are 25A each. If true the breakers on the campground panel box should reflect this.

If a 50A RV power cable is #6 wire then it's max load is 37A.
Typical 50A Power Cord
Wire Gauge Chart


So powering front and rear AC units independently should be ok, just don't anyone get the idea they can take one leg of a 50A panel and power an entire coach of 2 AC units, uwave, coffee pot and the DW blow drying her hair all at the same time. I don't think that ever works . . . .

Just my 2c.

Best,
- bob

No they are actually two 120 volt 50 amp lines for a total capacity of 100 amps at 120 volts. Total capacity is 12,000 watts. The 30 amp line has a capacity of 3,600 watts.

A 50A circuit is actually 2 120V lines so I would guess they are 25A each. If true the breakers on the campground panel box should reflect this.

If a 50A RV power cable is #6 wire then it's max load is 37A.
Typical 50A Power Cord
Wire Gauge Chart


So powering front and rear AC units independently should be ok, just don't anyone get the idea they can take one leg of a 50A panel and power an entire coach of 2 AC units, uwave, coffee pot and the DW blow drying her hair all at the same time. I don't think that ever works . . . .

Just my 2c.

Best,
- bob

why do you have to worry about wiring "throughout the coach" if you supply an adequately wired box, etc. for 50 amps? everything down stream will be protected by the appropriate breaker size.
bumpy

I'm with Ivylog on this one...I can't really see a mfg using heavy duty wiring on a 32' coach if they didn't have to. The simple fact they installed only ONE a/c originally indicates, at least to me, that the wiring would be inadequate to handle the extra current. I would tread lightly until I could verify the size wiring throughout the coach. An electrical fire, especially if I were sleeping with both a/c going would not be my cup of tea....Dennis

Just because they used stock boxes rated for 50A does not mean they used 50A wire. Yes you could replace using only one of the two hot wires in a 50A RV cord and when you overload the wire to your breaker panel hopefully the burning smell is only a smell, not fire.

What is the output of gen,

30amp and 50 amp transfer switch, different animal.

JumboJet wrote:

tropical36 wrote:
Not sure I get this and there should be a relay of sorts somewhere and even if your rig doesn't use a transfer switch for powering the rear ac from either the genset or shore power.
Simply spitting this 20amp rear ac genset circuit by using a 20amp plug and receptacle, will allow one the option of plugging into a separate pedestal circuit and thus freeing up the full 30amps for the rest of the coach. It's called a dual power adapter and there used to be a company out there that coined the term and sold a kit of hardware items, along with the instructions to go with it.
What you have shown, looks pretty elaborate and seemingly unnecessary. On the other hand, I really don't know what you have there without doing an evaluation of my own.
Also, on second thought, I did have an old coach at one time, with an inside switch for choosing the front or rear ac, but still could be wired as I've explained and as long as the genset has a 20amp breaker for solely feeding the rear ac.

Motor home did not have a 2nd A/C originally installed but was wired for EXCLUSIVE running from the generator.

The motor home has 30 AMP input.

I added a 2nd A/C unit (15,000 BTU) and wanted to be able to run both A/Cs while at campgrounds in high temperature Summer heat. Most campgrounds will not allow you to run the generator.

I can now plug into 50 AMP service at the campground - plug the 30AMP shore cable into the 30 AMP receptacle on my box, and plug a 20 AMP cord for the 2nd A/C into the 20 AMP receptacle on my box.

Most campgrounds have both 30 AMP and 15 or 20 AMP receptacles, but sometimes they may not be reliable. Plugging into a 50 AMP campground receptacle increases reliability. My outlet box splits the two 50 AMP feeds via the 30 AMP and 20 AMP breakers shown. My box is configured with a 6 gauge 4 wire pigtail.

Gottcha and you did good, but let me ask for the sake of education and you said that the genset does have a 20amp breaker that's feeding the rear ac? If so, I'm still thinking for the sake of simplicity, that the circuit could be split with a 20amp plug and outlet, as previously mentioned.

tropical36 wrote:
Not sure I get this and there should be a relay of sorts somewhere and even if your rig doesn't use a transfer switch for powering the rear ac from either the genset or shore power.
Simply spitting this 20amp rear ac genset circuit by using a 20amp plug and receptacle, will allow one the option of plugging into a separate pedestal circuit and thus freeing up the full 30amps for the rest of the coach. It's called a dual power adapter and there used to be a company out there that coined the term and sold a kit of hardware items, along with the instructions to go with it.
What you have shown, looks pretty elaborate and seemingly unnecessary. On the other hand, I really don't know what you have there without doing an evaluation of my own.
Also, on second thought, I did have an old coach at one time, with an inside switch for choosing the front or rear ac, but still could be wired as I've explained and as long as the genset has a 20amp breaker for solely feeding the rear ac.

Motor home did not have a 2nd A/C originally installed but was wired for EXCLUSIVE running from the generator.

The motor home has 30 AMP input.

I added a 2nd A/C unit (15,000 BTU) and wanted to be able to run both A/Cs while at campgrounds in high temperature Summer heat. Most campgrounds will not allow you to run the generator.

I can now plug into 50 AMP service at the campground - plug the 30AMP shore cable into the 30 AMP receptacle on my box, and plug a 20 AMP cord for the 2nd A/C into the 20 AMP receptacle on my box.

Most campgrounds have both 30 AMP and 15 or 20 AMP receptacles, but sometimes they may not be reliable. Plugging into a 50 AMP campground receptacle increases reliability. My outlet box splits the two 50 AMP feeds via the 30 AMP and 20 AMP breakers shown. My box is configured with a 6 gauge 4 wire pigtail.