SECTION 240.21.B.2 #1; WHERE IT STATES, THE AMPACITY OF THE TAP CONDUCTOR IS NOT LESS THAN 1/3 OF THE RATING OF THE OVERCURRENT DEVICE. SO WHAT WE ARE SAYING IS THAT IF WE RELOCATE A 100AMP FUSED DISCONNECT 22 FT AWAY, THE TAP RULE APPLIES, THE SIZE(RATING) OF THE CONDUCTOR CANNOT BE LESS THAN 33.5AMPS. SO THE SIZE OF THE FUSES WE CAN PUT IN THE DISCONNECT IS 100AMPS. BUT IF THAT IS THE CASE YOU ARE NOT PROTECTING THE WIRE.
TAP RULE
- Thread starter sleepy
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peter d
Senior Member
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- New England
Re: TAP RULE
Please turn off your CAPS.
Thank you.
Please turn off your CAPS.
Thank you.
Re: TAP RULE
No,We are not saying that at all,for one,if you are relocating an existing 100 amp disconnect 22' away,you should simply be extending the 100 amp feeder that was there before to the relocated disconnect with 100amp rated wire,this is not a tap but an extension.
If you are installing another fused disconnect 22' away you must size the tap conductor accordingly,for example installing a 30 amp fused disconnect and tapping the 100amp feeder with #10's thhn.,,,,,the #10's have an ampacity of at least 1/3 of 100 amps (40x3=120) and is acceptable to use as a tap conductor.If you were tapping a 200 feeder to a 30amp fused disconnect the #10 would not be allowed for the tap and would need to be upsized to a #6 (75x3=225).asuming all other tap requirements are met.
[ September 10, 2004, 11:46 AM: Message edited by: jap2525 ]
No,We are not saying that at all,for one,if you are relocating an existing 100 amp disconnect 22' away,you should simply be extending the 100 amp feeder that was there before to the relocated disconnect with 100amp rated wire,this is not a tap but an extension.
If you are installing another fused disconnect 22' away you must size the tap conductor accordingly,for example installing a 30 amp fused disconnect and tapping the 100amp feeder with #10's thhn.,,,,,the #10's have an ampacity of at least 1/3 of 100 amps (40x3=120) and is acceptable to use as a tap conductor.If you were tapping a 200 feeder to a 30amp fused disconnect the #10 would not be allowed for the tap and would need to be upsized to a #6 (75x3=225).asuming all other tap requirements are met.
[ September 10, 2004, 11:46 AM: Message edited by: jap2525 ]
- Location
- Illinois
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- retired electrician
Re: TAP RULE
In general, all that the "tap" rule does is to move the OCPD from the supply end of the conductor to the load end of the conductor. The OCPD on the supply end provides the short circuit and ground fault protection for the tap conductor and the OCPD on the load end supplies the overload protection.
Don
In general, all that the "tap" rule does is to move the OCPD from the supply end of the conductor to the load end of the conductor. The OCPD on the supply end provides the short circuit and ground fault protection for the tap conductor and the OCPD on the load end supplies the overload protection.
Don
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