Is it ever ok to double tap the main lug in a panel. I alway believed this was never allowed. I have a sellers electrician telling me it is ok. something about a 35 foot rule and something about crimping? The tap goes to the AC disconnect.
Any help would be appreciated.
Thanks
Have the seller’s electrician refer you to the local code that allows it.
Very unlikely that this is a proper connection. Do you have any puctures?
I know someone who had a meter panel burn up due to loose double taps. The power company came out and said “not our problem, not our box, call an electrican”.
She had it fixed by an electrician, the bill was quite high, they had to make a few trips, a cable was too short, it was below 15 degrees etc etc.
The owner ended up filing a complaint with the power company and getting reimbursed.
Here is why they had to pay:
100% violation for using a lug listed for one conductor with two conductors. Also the use of a white conductor as an ungrounded conductor is a violation as well.
RM has posted the correct cite for this violation.
It is possible to employ the tap rules to do what was asked about. however, this is not the correct way to do it.
It would be nice to post a picture employing the tap rule. Do you have one?
If yes, email it to me (whis11 @ charter.net) if your member status doesn’t allow picture posting.
Thanks.
I would really like to see that picture as well…
First it would help to understand that a tap has specific rules and conditions in which they can be used. A tap by definition has its OCP at the end, not where it originates. NEC Article 240.21 will spell these out.
No personal pics but here is one from another HI forum,
There is no image, Jim, simply the red “X” box…
Here’s a 10’ tap rule compliant installation. 400 amp feeder, #6 tap conductors (minimum 10% of feeder ampacity) to 15 amp circuit breaker. The lugs on the bottom accept two conductors (double lugs) in the #6 AWG to 500 kcmil range:
Thanks.
Do the lugs at the top, that are hidden, have a similar design accepting two conductors?
Yes, the load portion of the switch (top lugs) is factory wiring for a dimming system. The bottom portion is the feeder connection.
Nice pictures. Thanks for posting these.
Hey Guys-
I’ve always considered the above picture by Mr. Meier as incorrect due to the fact that you have a larger conductor and a small conductor tied together. The problem arising from the fact that the smaller conductor could be subject to more amps than it is rated for. That must not be the case then?
Kenny
The OCPD limits the current that can be drawn through the conductors. Current is not “pushed” from the transformer.
Okay, so in the picture that Mr. Meier posted, the breaker in the top distribution panel would protect the 6 guage conductor from having too many amps drawn through it, right?
So as long as there is an OCPD down stream, conductors of differing sizes can be tapped together…pending the lug was designed for the multiple taps?
Of course, and I’m sorry to have to ask, is there a way to easily determine whether or not a lug is designed for taps or not?
Kenny
Kenny, read 240.21 to better understand the tap rules. The OCP is provided downstream from the tap connection.
Unless listed for use with multiple conductors, just assume that the lugs are only listed for use with one conductor.
