Electrical Question

[clayinaustin]

The funny part is, he would not have to worry about it if he would just accept the 100 gals of gas it will take to run his on board generator. How many guys around here burn that in a couple hrs of boating.

true that!

 

[MacGyver]

What the inverter does is it takes 120 Volt / 20 Amp Ckt. and turns it into 30-50 Amp 240 Volts. It's just a step-up transformer. Most motor homes have this built in and come with an adaptor so you can run the a/c's off a 120 Volt Ckts. Dave

That can't be done. 20 amps from a 120 volt circuit stepped up has the same energy of only 10 amps at 240 volts (P = I X E). The transformer can increase the voltage from 120 to 240, but you'll never get 30-50 amps from it.

Oh, BTW, I'm a master electrician

 

[MacGyver]

OK. How about this?

Buying or building a "Y" adapter that runs two 15amp plugs into one 30amp connection. A straight hard-wired adapter. All 110 volt.

Nope, not gonna work.

 

[MacGyver]

I have a 30amp (from source) to 50amp (to motorhome) adapter. It's about 18 inches long. We plan to cut off the 30amp plug and splice two 15amp "household" plugs into the adapter. Does your "RV Guru" think this is safe?

Even though you will end up with two 15 amp cord ends, the duplex receptacle you are going to plug into is fed fron only one 20 circuit. You gain nothing.

 

[MacGyver]

This is exactly what I am looking for, except I want to have two 15amp plugs feeding the one 30amp.

Something like this Y adapter but two 15a to one 30a and on the same phase.

That adapter will "sorta work" in limited places. You must plug into two 30 amp 120V receptacles that are on opposite phases. And even with that, you'll never get 50 amps out of it, just the 30 amps your plugged into.

 

[MacGyver]

To use an adapter like that, you'd have to have two separate outlets on separate breakers AND ensure they were on the same leg of the 220. If not- boom.

And, now you take the risk of back-feeding into a circuit. Essentially, anything on either of those two breakers that was disconnected wouldn't be disconnected- If you popped one breaker open, the electricity would now be supplied to the open side of that breaker, coming backwards from your Y. You could kill someone.

Why not isolate that second AC unit and do a temp wire-around for a second connection?

Actually, to get the claimed 120/240, the two receptacles need to be on opposite phases for the adapter to work at all.

And the back feeding issue would only be applicable if their were 240 volt loads being supplied.

 

[MacGyver]

Buy gas for the generator while its cheap

 

[clayinaustin]

My friend built his electrical adapter. It worked fine.

 

[seebeagle]

If the gals you have on your boat weren't so hot looking, you wouldn't have to cool down

 

[northernoffshore]

I have a yamaha genator that powers my whole house during hurricanes. 6-8 gals a day 6600 amps? 100 gals for 4 days seems excessive.

 

[Spicy]

I have a yamaha genator that powers my whole house during hurricanes. 6-8 gals a day 6600 amps? 100 gals for 4 days seems excessive.

6600 watts not amps!!!!