mstrlucky74
Senior Member
- Location
- NJ
Is it NEC to have a disconnect switch on secondary andprimary side xfrmr? Thanks.
Xfrmr Disco
- Thread starter mstrlucky74
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
No, but in almost all cases you will have to provide overcurrent protection for the secondary conductors, and the results in a means of disconnect.
mstrlucky74
Senior Member
- Location
- NJ
The overload protection device in the panel on the line side of the X-fmr ( if that is what is used ) is used to protect the conductors to the line side, and, sometimes the load side of a X-fmr,.
The Overload protection on the secondary side of a X-fmr, (if required) is installed to protect the conductors on the 2ndary side of the X-fmr and may be an overload protection device installed in a panel as you have mentioned if placed in the correct location.
JAP>
mstrlucky74
Senior Member
- Location
- NJ
- Location
- Illinois
- Occupation
- retired electrician
You asked if the code requires a secondary disconnect, and the answer is no. The code does not require a secondary disconnect for a transformer. I expanded on that, as compliance with the secondary conductor protection rules in 240.21(C) will almost always result in a means of disconnect being installed, but the transformer rules do not require such a means of disconnect on the secondary.
That would all depend on where those 2ndary conductors were located and how far they were from the load side of the X-fmr.
As far as the need for a disconnecting means,,,, don_resqcapt19 already summed that up.
JAP>
mstrlucky74
Senior Member
- Location
- NJ
- Location
- New Jersey
- Occupation
- Journeyman Electrician
The primary disconnect is OK on another floor (distance is irrelevant) if the transformer is labeled with the location of the primary disconnect. Generally the secondary condcutors are limited to 25' without overcurrent protection so at 100' you may have a problem
Just to add to this,,,, adding a "disconnect" as stated in the OP on the secondary is not going to solve your problem.
JAP>
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Just to add to this,,,, adding a "disconnect" as stated in the OP on the secondary is not going to solve your problem.
JAP>
True and I did say that you need an OCPD within 25' so the disco would need fuses.
True and I did say that you need an OCPD within 25' so the disco would need fuses.
Yea, but you gave away the farm too early,,,, I have to post 30 times before anyone ever gives up any valuable information.
JAP>
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