Learned stuff about AC and 50 amp service

[JBM3M]

Have 2 AC units on my unit, I put in the second unit, had the version that did not need gateway. So as a test I ran them from a 30 amp 110v into a 50<-30 amp converter connection.



(Both legs on the 50 amp side are hot, meaning that they are simply connected together, thus supplying 30 amps in total to these at the same time. )



Both AC units would run, but they were not very cold at all. Running just one was quite a bit better. Ok, so I knew 30 amps would run them with the Easy-Start's.



Move ahead to a get together, temps about 80 which is hellish hot for us. Ran my Honda 3000, started running the units early so they were ahead of the heat. Well the sun beat on the generator about 5 hours after we started it.



Both units in the RV started to act up, then the generator started complaining and throwing overload condition. When things cooled down, running just one unit worked, but not so great.


Bought a HF Predator after seeing a friend with one. His was 3500, and he was only running one AC unit plus all sorts of other stuff, but it kept on ticking and was quiet. My poor little Honda is 18 years old and well used.



I got the 9500, which is a bit louder than I like, but I cannot hear it right next to the RV if the AC unit is blowing, so very tolerable. I did attempt to make a sound box then found out it wants 5 feet of clearance. Made a sound box for it, but I think it over heated, see below. It has to live in the truck in front of the hitch so sorta short on that distance without the cover, but no issues. (I really am getting to a point, hang on).



My surge protector showed 2 separate 110 lines coming out of the generator on the 240V setting, and if switched to 120 for that outlet only one leg was hot. Hmmmm do new test. Mind you it is 90's during all this part. Only one AC unit would work that way; swapped around and the other one didn't work.



But the one working was colder output than it ever had been. Cool Beans!! Back on the 240, again, both AC work and better than ever before. I am assuming off the generator (or a true 50 amp circuit) I was getting a brown out on the compressors because it just was not enough juice. This gen puts out 7600 in Eco mode, which is more than enough to run both sets at full power.



As final test this was all run for 4 hours straight, in the sun, and the AC were actually getting ahead of the temp. Part of the reason for that was the generator quit at 1/2 hour run time, HF exchanged no questions asked. (61 db @20 feet running both AC)



So, the moral here is, if you have 50 amp service you need 50 amp to fully utilize your systems. Now I need to make another extension for at home that reaches my 50 amp 220V outlet. (6-3 wire is spendy, probably need another 30 ft.)

[bsmith0404]

FYI, running the ACs on low power can damage them.

[spicercars]

Originally Posted by bsmith0404

FYI, running the ACs on low power can damage them.

Exactly Get yourself a plug in volt meter like the one camco makes. Will save you a lot of headaches.

[jxnbbl]

My EMS would have shutdown the whole system in these conditions...I'd only run one AC personally.

[ChuckS]

Actually a 50 amp RV can utilize 100 amps.. each leg is 50 amps with the normal configuration for air conditioners wired one on each leg..

When connected to a RV 50 amp pedestal that’s 12,000 watts …

[JBM3M]

I think the units are Okay, I know brown outs are not good for the system. Took a bit to figure out the way the wiring works.
Thanks

[bsmith0404]

Originally Posted by jxnbbl

My EMS would have shutdown the whole system in these conditions...I'd only run one AC personally.

Same here. Been in parks down in Mexico wheee power was unstable. Every time someone would plug in, it’d drop power momentarily to other sites. My EMS shut the system down each time.

[flybouy]

Couple things, first an EMS will prevent damage and running an a/c unit with low voltage WILL damage it. It may not appear damaged but the windings in the compressor will be weakened. The more often or the longer the low voltage condition persists the more damage is done. It's a simple formula called Ohms Law. When the voltage drops the amperage draw increases.

The line in the OP "add yet ANOTHER extension cord". How many feet is it from the plug at home to where the trailer sets? If the TOTAL run is 100' or more then you will need larger guage wire or you will create a voltage drop at the trailer and be in danger of creating more issues.

[JBM3M]

Originally Posted by flybouy

The line in the OP "add yet ANOTHER extension cord". How many feet is it from the plug at home to where the trailer sets?

It would total out to 75 feet if I did that. But unless I plan on using the AC here at home, don't need to make it.


Nothing I can do to undo the time at low voltage, will just have to suffer any consequences that may show later.

[travelin texans]

"So, the moral here is, if you have 50 amp service you need 50 amp to fully utilize your systems. Now I need to make another extension for at home that reaches my 50 amp 220V outlet. (6-3 wire is spendy, probably need another 30 ft.)" QUOTE

Be absolutely sure that's not a 220 volt powered plug or you WILL have problems. The plug may appear the same, but could be/should be wired differently for rv use as opposed to your dryer or welder.
__________________

[JBM3M]

Originally Posted by travelin texans

Be absolutely sure that's not a 220 volt powered plug or you WILL have problems. The plug may appear the same, but could be/should be wired differently for rv use as opposed to your dryer or welder.
__________________

Well that I do not understand. I thought all 220V is, is 2-110v hot legs, neutral, and ground and power is "combined" by device used. A 220v breaker pulls from 2 different hot lugs. How is an RV system different? Please explain.

[bsmith0404]

Originally Posted by travelin texans

"So, the moral here is, if you have 50 amp service you need 50 amp to fully utilize your systems. Now I need to make another extension for at home that reaches my 50 amp 220V outlet. (6-3 wire is spendy, probably need another 30 ft.)" QUOTE

Be absolutely sure that's not a 220 volt powered plug or you WILL have problems. The plug may appear the same, but could be/should be wired differently for rv use as opposed to your dryer or welder.
__________________

Depends if it’s 3 or 4 pin. 4 pin should be the same, 120 on each. The 3 pin is definitely a concern. The. Reason the 3 pin is different is on a RV only one is hot, on a typical dryer/welder, two are hot

[bobbecky]

Be also aware that you will occasionally find a park that has 208Y/120 volt power, and this works perfectly because the RV does not see 208 or 240 volts, only one or two legs of 120 volts. Hopefully you are seeing 120 volts prior to plugging your RV into the pedestal, not 110 volts. 110 and 220 are very old standard voltages that were replaced many years ago with 120 and 240 volts. If you start out with 110, you will quickly be under the minimum voltage required for most appliances.

[travelin texans]

Originally Posted by JBM3M

Well that I do not understand. I thought all 220V is, is 2-110v hot legs, neutral, and ground and power is "combined" by device used. A 220v breaker pulls from 2 different hot lugs. How is an RV system different? Please explain.

It depends how it wired to the breaker!

[flybouy]

".....So, the moral here is, if you have 50 amp service you need 50 amp to fully utilize your systems. Now I need to make another extension for at home that reaches my 50 amp 220V outlet. (6-3 wire is spendy, probably need another 30 ft.)"

The bolded line is what spurred this conversation. A 50 amp RV plug should be 4 wires. L1 is 120vac(black insulation), L2 is 120 vac (red insulation), one neutral(white insulation) and one ground (green insulation).

[bsmith0404]

Originally Posted by flybouy

".....So, the moral here is, if you have 50 amp service you need 50 amp to fully utilize your systems. Now I need to make another extension for at home that reaches my 50 amp 220V outlet. (6-3 wire is spendy, probably need another 30 ft.)"

The bolded line is what spurred this conversation. A 50 amp RV plug should be 4 wires. L1 is 120vac(black insulation), L2 is 120 vac (red insulation), one neutral(white insulation) and one ground (green insulation).

6-3 wire is actually 4 wires. Two hot (red/black) a white neutral and a bare ground. Although you can get 6-4 that has the green ground, I don’t know how important it is to have an insulated ground wire.

[flybouy]

Originally Posted by bsmith0404

6-3 wire is actually 4 wires. Two hot (red/black) a white neutral and a bare ground. Although you can get 6-4 that has the green ground, I don’t know how important it is to have an insulated ground wire.

In Romex or UF wire you are correct the ground is not part of the identifier. The OP stated he was making an extension cord so I would think he was talking about cable like SOOW.

[JBM3M]

Originally Posted by flybouy

".....So, the moral here is, if you have 50 amp service you need 50 amp to fully utilize your systems. Now I need to make another extension for at home that reaches my 50 amp 220V outlet. (6-3 wire is spendy, probably need another 30 ft.)"

The bolded line is what spurred this conversation. A 50 amp RV plug should be 4 wires. L1 is 120vac(black insulation), L2 is 120 vac (red insulation), one neutral(white insulation) and one ground (green insulation).

Exactly and that is what it is


Sheesh, what a can of worms I opened. The point has been totally lost because of nomenclature and misunderstanding.

6-2 wire is three wires, hot, neutral, ground
6-3 wire is four wires, black hot, red hot, neutral, ground.

[JBM3M]

Originally Posted by travelin texans

It depends how it wired to the breaker!

explain because
"How it is wired" is a new one on me. Like I said each leg of a 220vac breaker (on a conventional house panel) pulls off of one (separate) 120vac lug in the box. Each leg sends out 120vac to the receptacle. I know of no other way to wire 220vac, please explain how to wire differently

[rhagfo]

Originally Posted by bsmith0404

6-3 wire is actually 4 wires. Two hot (red/black) a white neutral and a bare ground. Although you can get 6-4 that has the green ground, I don’t know how important it is to have an insulated ground wire.

Only if you are referring to romex cable, and usually 6/3 with ground. If the cable is cord type like SOOW then it would be either 6/4 or 6/3 8/1.
If flexible cord then all conductors need to be insulated.