Quick electric question

[RoadTrip]

I have a house 50amp receptacle, two pole with two 40amp breakers. Does this sound right?

Licensed electrician installed, but he's been hard to get ahold of. I guess I just didn't expect a two-pole design for 110. Can someone smarter than I tell me if this seems kosher?

I realize I have a 30 amp MH, and realize that we'll only need an adapter to plug in, but when we told the electrician we want an RV plug in - we didn't own an RV so those where his only instructions - and now we're trying to figure out if we have a 220 line or 110 line.
thanks!

[Herk7769]

Well, I think (hope) he installed a 50 amp service fused to 40 amps (well within your needs BTW). Hopefully he used a 3 wire with ground wire (black, red, white, and copper).

You see your house current is 220 volts at the top of the panel but you have a neutral grounded in the box. Each "pole" of your 2 pole breaker is 110 volts (1 pole A phase and the other pole B phase) since each pole is returned via the neutral to ground and you should never see 220 volts at the plug if it is wired correctly and you test the socket to ground or neutral (and not the other hot leg).

The 50 amp service, when wired correctly, is 2 110 volt circuits on different phases so that when one leg is hot the other leg is cold every 1/60th of a second (60 cycle power).

Did that help or confuse?

[prairiecamper]

A 50 amp receptacle with two 40 amp breakers would suggest to me 220 volt! Don't plug anything in until you know for sure!

[Herk7769]

Yes, a properly wired 50->30 adapter will only use one pole of the two available.

No way to tell which without tracing the wires back to the panel. It does not matter since the 220 breaker in your panel (2 110 breakers linked together) will trip if any individual leg is overloaded.

[RoadTrip]

Originally Posted by herk7769

Well, I think (hope) he installed a 50 amp service fused to 40 amps (well within your needs BTW). Hopefully he used a 3 wire with ground wire (black, red, white, and copper).

You see your house current is 220 volts at the top of the panel but you have a neutral grounded in the box. Each "pole" of your 2 pole breaker is 110 volts (1 pole A phase and the other pole B phase) since each pole is returned via the neutral to ground and you should never see 220 volts at the plug if it is wired correctly and you test the socket to ground or neutral (and not the other hot leg).

The 50 amp service, when wired correctly, is 2 110 volt circuits on different phases so that when one leg is hot the other leg is cold every 1/60th of a second (60 cycle power).

Did that help or confuse?

helpful - very helpful. Do I need to go buy a tester of some sort, or is the fact that the receptacle itself says "50amp" on it enough evidence that it's not 220 (i have no idea if there even can be a 50amp with 220)

[Herk7769]

Originally Posted by prairiecamper

A 50 amp receptacle with two 40 amp breakers would suggest to me 220 volt! Don't plug anything in until you know for sure!

A 50 amp RV socket is actually wired from a 220 breaker; just the neutral needs to be carried to the socket as well as the 2 - 110 hots of the 220 breaker.

A "true" 220 appliance does not need a neutral and is typically wired with 2 hot wires and a copper ground wire (no neutral). Examples of 220 only appliances are a 220 volt water heater or dryer.

Wiring a 30 amp RV socket using a wiring set up like a dryer is the danger. While a 30 amp RV socket LOOKS like a dryer socket and should be 220; it is NOT.
It is wired 110 volts like a duplex wall socket.

Far less likely the electrician got it wrong (through not impossible) with a 50 amp service.

[prairiecamper]

Yes I know, but since you were already there I didn't elaborate! You're faster than a speeding bullet BTW. Thanks

[prairiecamper]

Originally Posted by herk7769

A 50 amp RV socket is actually wired from a 220 breaker; just the neutral needs to be carried to the socket as well as the 2 - 110 hots of the 220 breaker.

A "true" 220 appliance does not need a neutral and is typically wired with 2 hot wires and a copper ground wire (no neutral). Examples of 220 only appliances are a 220 volt water heater or dryer.

Wiring a 30 amp RV socket using a wiring set up like a dryer is the danger. While a 30 amp RV socket LOOKS like a dryer socket and should be 220; it is NOT.
It is wired 110 volts like a duplex wall socket.

Far less likely the electrician got it wrong (through not impossible) with a 50 amp service.

Our dryer plug has a neutral as I believe the motor is only 110 and requires the neutral.

[RoadTrip]

whew - thanks herk! I wouldn't think there'd be any confusion b/c not only did we tell him its for the RV, he labeled it as such AND it's in the garage - in the RV bay.

while I'm typing this out - just heard back from the electrician. 220!

[TURBS]

Originally Posted by RoadTrip

whew - thanks herk! I wouldn't think there'd be any confusion b/c not only did we tell him its for the RV, he labeled it as such AND it's in the garage - in the RV bay.

while I'm typing this out - just heard back from the electrician. 220!

Electricians assume 220 when they see two things.

50 amp service
50 amp outlet


Turbs

[Herk7769]

Originally Posted by RoadTrip

helpful - very helpful. Do I need to go buy a tester of some sort, or is the fact that the receptacle itself says "50amp" on it enough evidence that it's not 220 (i have no idea if there even can be a 50amp with 220)

It sure can be 100 amp 110 volt.

So how to check?

So say you don't feel like making that way cool home made 50 amp service tester, but do have a $9.95 meter in your tool box but other than making it beep you have no idea how it works.

The "V" is the voltage setting you will need to test for.

The "V" with the horizontal line is "DC" Battery and is you are using that to test the battery voltage it should be on the "20" scale. The red lead goes to where you expect to find positive and the black lead to where you expect to find ground. If the result has a Minus (-) in front of it your leads are backwards.

The "V" with the ~ next to it is "AC" and you will use the highest number on your meter (usually "250") The color of the leads do not matter because AC alternates and the polarity switches back and forth 60 times a second.

The socket has 3 "blade" holes and a round hole. The round hole is ground (easy).

The blade holes are where the juice is. The two on each side should hold the two "hots" and the one at the bottom (or top if the socket is oriented that way) is the NEUTRAL.

Using the meter on "V" "~" (250), insert the tips of the leads into the ROUND hole and into the middle (lower or upper) square hole.

The voltage should be ZERO. IF NOT, GET A NEW ELECTRICIAN IMMEDIATELY (call a lawyer you have a good law suit as well). Oh, and do NOT plug in your camper.

Using the meter on "V" "~" (250), insert the tips of the leads into the LEFT Rectangular (blade) hole and into the middle (lower or upper) blade hole.

The voltage should be 110 - 120 volts. IF NOT, GET A NEW ELECTRICIAN IMMEDIATELY (call a lawyer you have a good law suit as well). Oh, and do NOT plug in your camper.

Using the meter on "V" "~" (250), insert the tips of the leads into the RIGHT Rectangular (blade) hole and into the middle (lower or upper) blade hole.

The voltage should be 110 - 120 volts. IF NOT, GET A NEW ELECTRICIAN IMMEDIATELY (call a lawyer you have a good law suit as well). Oh, and do NOT plug in your camper.

Using the meter on "V" "~" (250), insert the tips of the leads into the RIGHT Rectangular (blade) hole and into the LEFT blade hole.

The voltage should be 220 - 240 volts. IF NOT, GET A NEW ELECTRICIAN IMMEDIATELY (call a lawyer you have a good law suit as well). Oh, and do NOT plug in your camper.

So if all tests are good to this point, plug in your 50->30 amp adapter.

Using the same settings on your meter and holding the 30 amp socket you should see: 2 blade holes and a round ground (as opposed to ground round which makes great burgers).

The blade holes are where the juice is. The two on each side should hold the ONE "hot" and the one other is connected to the NEUTRAL.

Using the meter on "V" "~" (250), insert the tips of the leads into the RIGHT Rectangular (blade) hole and into the LEFT blade hole.

The voltage should be 110 - 120 volts. IF NOT, GET A NEW PIGTAIL ADAPTER IMMEDIATELY (call a lawyer you have a good law suit as well). Oh, and do NOT plug in your camper.

Hope this helps. I had some fun so please forgive me trying to make a boring subject interesting (and hopefully humorous - not humerus which is a bone)

[Herk7769]

Originally Posted by RoadTrip

whew - thanks herk! I wouldn't think there'd be any confusion b/c not only did we tell him its for the RV, he labeled it as such AND it's in the garage - in the RV bay.

while I'm typing this out - just heard back from the electrician. 220!

No worries. A 50 amp service is wired 220 VAC from the panel.

AS LONG AS IT HAS A 50 AMP RV SERVICE SOCKET.

220 VAC to a 30 AMP RV SOCKET is melt down city...

[RoadTrip]

Originally Posted by herk7769

No worries. A 50 amp service is wired 220 VAC from the panel.

AS LONG AS IT HAS A 50 AMP RV SERVICE SOCKET.

220 VAC to a 30 AMP RV SOCKET is melt down city...

So if the outlet is correct, i'm good?

Now i'm waiting on my question whether neutral is run to the outlet - let you know when I hear that one.

And thanks for the humor - you're a punny guy!

[Herk7769]

Yes sir.

As long as there is 110-120 volts between the LEFT or RIGHT square socket holes and the NEUTRAL square hole (not just the ground!).

If he only ran 2 wire with ground, he did it wrong and it is not wired correctly.

[Herk7769]

Originally Posted by prairiecamper

Our dryer plug has a neutral as I believe the motor is only 110 and requires the neutral.

Not familiar with your dryer at all. My 220 dryer just has a 2 wire and ground. (No white neutral). The motor is 220 as well as the heating elements.

[prairiecamper]

Interesting here is what I found!

Wiring a Dryer Power Cord

I guess there is more to it than meets the eye.

[Herk7769]

Originally Posted by prairiecamper

Interesting here is what I found!

Wiring a Dryer Power Cord

I guess there is more to it than meets the eye.

How bout that. My 1954 home has the 2/w G plug.
Dryer works great.

[MillerTime]

I was going to say most all new homes have 4wire plugs for ranges and dryers

[fast murray]

If a customer calls up wanting a RV outlet and don't know what size they're going to need, we sometimes install a 50 amp 240 volt outlet that will either be correct for the RV the have now or will have, or they can use a dogbone.

[RoadTrip]

Originally Posted by fast murray

If a customer calls up wanting a RV outlet and don't know what size they're going to need, we sometimes install a 50 amp 240 volt outlet that will either be correct for the RV the have now or will have, or they can use a dogbone.

Ok - I googled dogbone and it's just a regular adapter?

Are you saying that with the adapter, I can plug my 30amp MH into a 50amp/220v outlet and everything's cool? I only ask b/c I was under the impression 220 is bad for 110 items - but i have to admit I'm clueless about this.