joebedford wrote:
1971duster340 wrote:
smkettner wrote:
Yes 30 amp 240v breakers are in virtually every home..
But it's a 2 pole gang operated breaker (120v+120v = 240v), not single pole 240V breaker. Only other countries have 240v on one breaker.
Yes, that's what I meant but didn't express well. You need a ganged breaker to get 240V (in USA, Canada). No single breaker will give 240V. I can't understand how an "electrician" could make this mistake.
This is easier to do than you might realize. NEMA has about 50 different configurations for a straight blade outlet. These outlets are labelled but not the way you might think. The terminations are labelled as W, X, Y and G. They are not labelled as hot, neutral and ground.
Before I bought my first RV, I had very little experience with 120V 30A outlets. If a request is made to put in a 30A outlet, it would be very easy to make a mistake and install a 240v 30A outlet.
Then there is the commercial side where a 30A outlet could be 120V, 208V, 240V, 277V, 347V, 480V, or 575V.
Not all 30A outlets are the same. Not by a long shot. The request for an outlet has to be very specific. The person making the requests needs to make it clear that a 120V 30A outlet need to be installed for an RV. An RV outlet is listed in NEMA but the application is specific to RV's and has very few other applications that I know of.
It also helps to have the device available to make sure that all terminations are done properly. If the RV, in this case, is in storage or otherwise not available, then it is again very easy to make a mistake and connect 240V to the outlet.
If the customer supplies the material, then this compounds the issue. There are cables with a single black and white, black, white and red, and black, white, red and blue. To add to this extension cable counts the ground as a conductor. Most other cables do not count the ground as a conductor.
If the customer tells the electrician that a 3 conductor cable is needed for a 30A outlet is it an SO(extension) cable, or NMD(romex type of cable) or something else.
Never come to the conclusion that electrical is very basic. A good tradesman can make it look easy but there is a lot to keep track of. Even for a 120V 30A outlet.
