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lenjen · 08-02-2013, 03:13 PM

This probably has been discussed many time but it is not coming up in my search. My coach is 50 amp, most RV CG's we go to are 30 amp. I use a short dog bone to reduce to 30 amp. I haven't had an issue but I'm very careful not to run AC/Microwave/ hair dryers/ etc at the same time.

Am I understanding this ad correctly? Ad shows the Y with one 50 amp end and two 30 amp ends. As some sites have two 30 amp receptacles, would this allow me to operate like normal 50 amps service?

50 Amp 125/250V RV Female - (2) 30 Amp RV Male Plus Y-Adapter with Powersmart LED's - Furrion F5431RY-SB - Electrical Cords - Camping World

thank you for any input...
Sandi

steveclv · 08-02-2013, 03:24 PM

1. 2 30's doesn't make 50 - a 50Amp connection gives you 2 * 50amp supplies = 100amps - just be aware of that when powering up on the circuits

2. The Y connection will only work if the 2 30amp connections that feed it are on SEPARATE phases and do not have a Earth Leakage Circuit Breaker - that means that on about 50% of pedestals it won't work.

When allowed, in the past I have been given permission to use the 30amp from one pedestal and use a 30amp extension to connect to the next sites pedestal - when they wire up the CG then tend to use different phases for each lot space and it makes it possible to use the Y

I have had one for about 6 years and maybe used it on 3 occasions!

lenjen · 08-02-2013, 04:07 PM

Steveclv, thank you. The most I know about electricity is you plug in and it works. So anything the least bit technical is beyond me.

The sites where I thought this might be possible would be where 2, 3 or 4 RV's can use the same post with up to 4 receptacles per box.

If I understand your reply the above sites probably would not give me the extra 20 amps. Correct?

Sandi

FlyingDiver · 08-02-2013, 04:43 PM

The most you're ever going to get using that is 2x30amps = 60amps. Not the 2x50amps = 100amps for a real 50amp connection. The major downside is that if the two plugs you connect to are on the same phase, you're going to do a major overload on the neutral wiring and burn something up. Unless you're absolutely sure you'll be able to test the plugs to make sure they're on opposite phases, don't do it.

lenjen · 08-02-2013, 04:49 PM

Thank you, FlyingDiiver. I saw the ad and thought the product might be a good thing... but 2 negative replies are enough for me to not buy or attach it to my RV.

Ramblin · 08-02-2013, 04:56 PM

I have one and have used it successfully a few times.

BFlinn181 · 08-02-2013, 05:02 PM

In addition to the above, you have to know how your RV is wired for 50 amps. Two hot leads of 50 amps come into the coach. The alternating current is in opposite phase so not to overload the shared neutral wire. The the RV, each leg is used to power part of the rig. One might power the front A/C, the front TV, and the coffee pot. The other phase might cover the rear A/C, the Converter/Inverter, bathroom outlet (hair dryer) etc. If you hook one leg to 20 amps and need 23, you'll trip a breaker. If one is hooked to 30 amp and is only using 15, you'd need to switch plugs at the pedestal. Many times the 20 amp circuit on the pedestal is GFI protected, it will trip when combined with the 30 amp circuit. In addition, ask at the office if it's O.K. to hook up to more than one outlet in the pedestal, many will want to charge more.

At minimum I'd be sure to have an EMS so I could monitor amp usage and protect the RV.

clyon51 · 08-02-2013, 05:43 PM

Quote:

Originally Posted by FlyingDiver

The most you're ever going to get using that is 2x30amps = 60amps. Not the 2x50amps = 100amps for a real 50amp connection.

The major downside is that if the two plugs you connect to are on the same phase, you're going to do a major overload on the neutral wiring and burn something up. Unless you're absolutely sure you'll be able to test the plugs to make sure they're on opposite phases, don't do it.

I agree FD. What I question is, or would like clarification, the 50a portion neutral of the adapter is capable, and I would assume so are the 2 30a portions are capable. So you are saying the neutral in the pedistal box (on the same phase) would be under overload, not the adapter or coach cable, correct?

Not that it should mean go ahead, 'cause it aint a gonna hurt my stuff' of course

Just curious. Also, how can one determine separate phases on two outlets. Never had to worry about that before.

BFlinn181 · 08-02-2013, 06:26 PM

If you were using the full 30 amps of each leg on the same phase, the neutral would be carrying 60 amps. It is only rated for 50 amps. Your shore cord, connectors in the ATS, plugs, etc. could be over heated.

Jim_HiTek · 08-02-2013, 06:36 PM

Of course you have a digital volt meter, right?

With that set at over 240Vac scale, you plug one lead into the hot of one 30a outlet, and the other lead into the hot of a different 30a outlet. If you read 240Vac, then they are out of phase (a good thing). The same would be true if you plugged one lead into the hot of a 20A outlet on the same pedestal. But as has been mentioned, there may be a GFI system installed and it won't allow you to 'Y' the circuits to the same RV. Other times, you'd be fine.

As far as using the Y adapter on two 30A systems that are IN-PHASE, you would measure Zero volts between the hots. As mentioned, you could potentially have 60A running through your 50A RV cord neutral if you connect up that way. Not likely if you're conservative and don't try to run to many devices at once. And of course, things like a 240V oven wouldn't work in that case. The panel would light up, but there wouldn't be enough voltage to run the burners...only a concern if you have an all electric rig.

Some times you'd be able to happily connect up that way, and that would probably be in newer parks with no neighbors other times probably best to just use your 50A to 30A adapter.

lenjen · 08-02-2013, 06:46 PM

Quote:

Originally Posted by Jim_HiTek

Of course you have a digital volt meter, right?

.

Are you asking me... the OP? You must be kidding! Did you read my second post. No I would not know how to use one if I had it. I do have a surge protector. With the replies above, I'll stay with my one cord with a reducer from 50 to one 30.

clyon51 · 08-02-2013, 06:50 PM

Quote:

Originally Posted by BFlinn181

If you were using the full 30 amps of each leg on the same phase, the neutral would be carrying 60 amps. It is only rated for 50 amps. Your shore cord, connectors in the ATS, plugs, etc. could be over heated.

Ok, so it would be correct to say the single neutral in the 50a cord would only carry 50a max (even if 100a is being used) because the 2 phases cancels out one of the 50a legs?

In other words, if 60a were being used in this case, the neutral would carry the 60a on the rated 50a neutral?

Where I'm still confused is modern power is 3 phase. And were talking the 2 inbound legs from the power company as being 2 phases. I guess that's something I need to investiage myself. I didn't mean to muddy up the thread.

BFlinn181 · 08-02-2013, 07:00 PM

Quote:

Originally Posted by clyon51

Ok, so it would be correct to say the single neutral in the 50a cord would only carry 50a max (even if 100a is being used) because the 2 phases cancels out one of the 50a legs?

In other words, if 60a were being used in this case, the neutral would carry the 60a on the rated 50a neutral?

Alternating current goes from 120 v (+) to 120 (-) 60 times (cycles) a second. In an RV 50 amp outlet, as one leg is decreasing, the other leg is increasing, so the neutral leg never 'sees' more than 50 amps. If the two 30 amp circuits were being supplied in the same phase (common in one pedestal) then they are both supplying 30 amps at the same instant. The neutral would then carry the combined 60 amps.

RustyJC · 08-02-2013, 07:34 PM

Quote:

Originally Posted by clyon51

Where I'm still confused is modern power is 3 phase. And were talking the 2 inbound legs from the power company as being 2 phases. I guess that's something I need to investiage myself. I didn't mean to muddy up the thread.

50 amp 120/240V service uses only 1 phase from the power company. That phase powers a center-tap neutral transformer to provide split-phase 120/240 V output. The ground conductor is not shown in the following diagram.

Rusty