Need advice on 30amp/50amp service and a cheater cord

[Phil H / Chicago]

The campground we have a seasonal site at only has 30amp service available. The coach is 50amp but we did ok last summer by simply watching what we used. It took a couple tripped breakers but we finally learned what worked at the same time and what didn't. I have been reading and found the cheater cord and wondered about it. Seems to be like so many options, some say yes it is fine while others say no.

At the pole there is a 30amp plug with a 30amp breaker but there is also a 20amp plug (actually 4 of them) with a 20amp breaker. I am assuming that two breakers indicate two separate circuits, which I plan to check this weekend when I go to check on the coach. Does that mean that the cheater cord is an option to access more power?

I have also been told that I should ask the campground about it use anyway. I don't want to do anything that would damage the coach nor others property.

As an option I was thinking I will just run a 12 gauge extension cord off the 20amp plug into the vehicle and use it for say the microwave so we have a little more freedom.

Thanks,
Phil

[NJT5047]

You may find that the 20A duplex and 30A share the same feed. 
Try it and see what happens.   Generally, code or no, a campground with only 30A boxes is underpowerd when the CG is at capacity.   It may not be to code.  CGs around major cities are usually wired to code..those in the boonies may be whatever got the box working. 
You might trip the main panel breaker...not the pole breaker.  If not, you may benefit from the "cheater" arrangement.   
I often plug in a block heater or outside lights (my Jimmy Buffet Party Palm Tree) to the 20A duplex.  Never had any issues doing this. Still could.  The 30A is fused at a main panel and that's where the problem will appear.  Unless the panel fuse is not correct and you smoke the pole wiring.  That's a possibility. 
You would probably be ahead of the game if you ask the campground folk if "cheater" adapters will work.  They'll know.  The maintenance guy will know too.  Maybe you could catch him and ask...incogneeter? 
Campgrounds usually sell one power source...either 30A, 20A, or 50A.  They don't expect all the outlets in a box to be utilized.  NEC codes may, but CGs may not.
A little "local knowledge" might go a long way before you plug up and possibly toast their box...for which you may be held responsible.   Probably not, but you could immediately be declared 'persona non grata' and expelled from the CG. 
If you have another unused nearby box, with a 30A outlet...you could use an adaptor for your other leg without any negative consequences....ASSUMING no 220V appliances.   Often the boxes are set next to each other and you could easily use two boxes.  That would give a real 30A per leg.   The CG will probably take a dim view of this "two box"  arrangement.  They might want to 'rent' you the other campsite associated with the 'borrowed' power pole.
JR

 

[Lin]

How would you tell if the 30a and the 20a are really on the same circuit?

[Sean]

You need a voltmeter that can read to at least 250 volts AC.

Put one test lead in the hot slot of the 30-amp receptacle, and one test lead in the hot slot of the 20-amp receptacle.  If you read 240, they are on separate legs, and you can use the cheater device IF neither side has a GFCI.  The cheaters will not work with GFCI, period.

If your meter reads zero, the two receptacles are on the same leg.  The cheater device will probably work (again, as long as there is no GFCI), but any 240 volt appliances in your coach will not.  In this case, you should limit your total draw to perhaps 80% of the available total, since the return current will split across the two halves of the cheater possibly in different proportion then the respective hot currents, and you don't want to overload the smaller neutral.

-Sean
http://ourodyssey.blogspot.com

[Phil H / Chicago]

Hi Sean,

Check your email. I send your some info.

Thanks,
Phil

[TomC]

Thoughts on cheater cords- if you do split the service with 20 and 30 amp, you'll get exactly that- 20 amps on one leg and 30 amps on the other.  On the other hand if you use a 20 amp plug and a 30 amp plug with the same phase wiring, you can have a total of 50 amps for both sides-meaning if you go over 30 amps on one side, you'll still pull the load.  And since the wiring is set up for 50 amps, whether you have 50 amps running through either side and then coming back through the single common wire won't matter.  Now trying to run 100 amps single phase through the plug would burn it up.  Good Luck, TomC