Adapter for 60 amps feed to RV

[Mongobird]

There are not too many rigs with 30 amp service, which will accept 60 amps at 120 volts.

Additionally the only kind of rig power that could benefit from this, is a rig that is a 50 amp rig. In that case L1 and L2 would each receive 50 amps at 120 volts, for a total of 100 amps, 50 on L1 and 50 on L2.

As has been pointed out previously one generally cannot find two 30 amp receptacles adjacent to each other where one runs off L1 and the other runs off L2.

If this was to be used at home, the best thing would be to use the two 30 amp circuits and wire them to a 14-50 receptacle and feed them with a two pole breaker, and in doing so assuring that they are on separate phases in the panel box. This would give you a 50 amp receptacle, which is only capable of delivering 30 amps on each phase. But it would not burn out your neutral return, and if something was wired incorrectly it would not be a Widowmaker adapter cord.

[oatmeal]

Originally Posted by Mongobird

I have actually done that, and it does not trip the GFCI outlet. To make it clear what I'm doing is I'm adapting a 30 amp mail plug to a 20 amp 120 volt male plug and plugging it into the GFCI. It does not trip the GFCI.

Did you do it through a device like the one being discussed here? That's what I think twinboat is talking about, because "one" 30-amp plug is specified, not "a" 30-amp plug. The cheater box has two 30-amp plugs coming out of it, and it's common for people to use it where there's a 30-amp outlet and a 15-amp outlet, and they find out that if the 15-amp outlet is GFCI protected, the GFCI trips.

That's not the same as, for example, taking a 30-amp shore power cord and putting a 15-amp adapter on it, and plugging it straight into a 15-amp GFCI outlet. That won't necessarily trip the GFCI.

Or maybe you ARE successfully using the cheater box on a GFCI outlet? Because of how it's designed to work, you wouldn't expect it to work on a GFCI except in a controlled laboratory experiment, and not in everyday use where the electrical draws vary on each leg depending on what's plugged and what's turned on.

[wolfe10]

Reply in BLUE

Originally Posted by mongobird

there are not too many rigs with 30 amp service, which will accept 60 amps at 120 volts.


Actually, there are none, as the main breaker in the coach 120 vac panel is 30 amp.


Additionally the only kind of rig power that could benefit from this, is a rig that is a 50 amp rig.



True

[dssl]

You could potentially slightly overload the neutral wire in your 50 smp rv but probably not.

If both of the 30 amp plugs are on the same phase then the neutral wire could get 60 amps, which is greater then 50. If the 2 30 amp plugs are on different phases then no problem, just like no problem with a 50 amp connection. To check if they are on the same phase measure the voltage between the two hot legs of the 50 amp plug. If the voltage is 0v then they are on the same phase, if 240v different phases and nothing to worry about.

If they are on the same phase you need to make sure not to exceed 50 amps. Although 6 guage wire actually has a capacity of 55 amps, so from a practical perspective it would be difficult to overload the neutral wire. But on the other hand be careful and don't try to max everything out.

[Mongobird]

Originally Posted by oatmeal

Did you do it through a device like the one being discussed here? That's what I think twinboat is talking about, because "one" 30-amp plug is specified, not "a" 30-amp plug. The cheater box has two 30-amp plugs coming out of it, and it's common for people to use it where there's a 30-amp outlet and a 15-amp outlet, and they find out that if the 15-amp outlet is GFCI protected, the GFCI trips.

That's not the same as, for example, taking a 30-amp shore power cord and putting a 15-amp adapter on it, and plugging it straight into a 15-amp GFCI outlet. That won't necessarily trip the GFCI.

Or maybe you ARE successfully using the cheater box on a GFCI outlet? Because of how it's designed to work, you wouldn't expect it to work on a GFCI except in a controlled laboratory experiment, and not in everyday use where the electrical draws vary on each leg depending on what's plugged and what's turned on.

No, I was not using a cheater box. Simply an adapter for a single phase connection.

[Tha_Rooster]

If you have (2) 30 amps lines L1 and L2 how can you ever get 60 amps. You can say it’s 60 but it’s not a drawable amperage. It will never have over 30 amps per leg of drawable power. If you have 30 single pole cheater plug with a total of 30 amps it doesn’t matter which leg pulls the most it has max combined of 30 amps . Just my opinion and not a certified electrician.

[Jon_C]

Originally Posted by Tha_Rooster

If you have (2) 30 amps lines L1 and L2 how can you ever get 60 amps. You can say it’s 60 but it’s not a drawable amperage. It will never have over 30 amps per leg of drawable power. If you have 30 single pole cheater plug with a total of 30 amps it doesn’t matter which leg pulls the most it has max combined of 30 amps . Just my opinion and not a certified electrician.

Its 60 amps total, 30 amps in one leg and 30 amps in the other leg for 60 amps total. Each leg has its own 30 amp 120v breaker so each leg can pull up to 30 amps. This is referring to the device the op specifically posted about in post1.

[Tha_Rooster]

Originally Posted by Jon_C

Its 60 amps total, 30 amps in one leg and 30 amps in the other leg for 60 amps total. Each leg has its own 30 amp 120v breaker so each leg can pull up to 30 amps. This is referring to the device the op specifically posted about in post1.

Isn’t your post just like my quote you are using?

[Jon_C]

Originally Posted by Tha_Rooster

Isn’t your post just like my quote you are using?

Ok I give up..

[Solo_RV_Guy]

Okay, we need to think in terms of *circuits* and not blindly discuss amperage.

Likewise, "out of phase" is a misnomer when applied to the "single, split-phase 120v/240v service". The center tap that creates the neutral does not cause a change in the *time* relationship between L1 and L2. Rather, a polarity relationship is established. Yes, I know polarity is fundamentally a DC thing, but the AC waveform is opposite on each side of the neutral, and that's how the neutral carries only the imbalance of current between L1 and L2.

So... with the 2-TT30 combiner-to-NEMA 14-50, you may or may not overload the service neutral at the pedestal(s), if both TT30 receptacles are on the same Line. Unless you have a 240V clothes dryer or water heater in your RV, you'll never know the difference but the neutral will heat up just the same.

[Donskiman]

It's interesting this discussion is still going on, almost entirely by people who probably never even used this device. We did use this device on our last trip. We were hooked up with it for about a week and there were zero issues.

Reminds me of an old saying. A bumble bee shouldn't be able to fly, but don't tell the bee that!

[wjijr]

Originally Posted by twinboat

If its a double 30 amp to single 50 Y adaptor, then not really. That will give you 30 amps at 120/240 volts. So 30 amps per leg. A potential of 60 amps but never called that.

Remember, your 50 amp RV is 50 amps at 120/240 volts, so it can potentially supply 50 amps per leg.

AGREE. RV 50AMP gives you two 50AMP service legs or 12,000 watts (never referred to as 100AMP). The power cable that has been referenced above gives you two 30AMP services legs or 7,200 watts (never referred to as 60AMP).

[Charlesland]

It seems rare that you would have 2 30 amp outlets that close together.

[Molfpedal]

Originally Posted by Jon_C

Yes it can provide a total of 60 amps (30 amps x2 legs)

A normal 50amp circuit provides a total of 100 amps ( 50 amps x 2 legs)
With a 240vac source.

My only concern with this device would be possible load of 60 amps on the neutral wire if you plug into 2 30amp plugs with the same phase 120v (measure 0v across the 2 source legs)

As long as each 30a circuit is opposite phase (measure 240v across the 2 source legs) the load on neutral will be fine.

A normal RV adapter plug of this type is designed to convert two 30amp 120vac circuits to connect to a 50 amp tv plug which is two 50 amp 120vac circuits as RVs normally only have 120 vac.