Tap rule

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Strife

Senior Member
I got a 90A main breaker with #3 wires branch circuit going from the MDP to a 100A disconnect feeding a baler with a FLA of 40, baler has full controller with overload and all bell and whistles. The fuses on the baler are 70A right now. Customer wants me to hook up a trash compactor with a FLA of 24. Compactor also has full controller with overload protection. The main for the 90A circuit is 120-140 feet away, but it's almost impossible to run a new conduit to the location without clearing the whole floor. So if I read the tap rule correctly can I?

1: Tap the 90A circuit ahead of the Baler disconnect with #6 wires going into a 60A disconnect and hook the trash compactor? The 60A run will be about 15feet so it falls under the "under 25'" rule.
2: Can i do said taps inside the existing disconnect (just remove the #3 line side from the disconnect and install polaris taps), or do I need to install a box where the polaris taps will be? (I can cut a bit of the conduit and install a box, so it's no big deal to install a box, but I'd rather not).
Thank you.
3: Does the ground have to be for 90A or for 60A on the new tap? I'd assume it'd be required for 90A (the overload is protected on the load side by the 60A disconnect, but in case of a short between???
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
The tap can occur anywhere. Look at 250.122 (G) for the EGC. It should be sized to the larger (90 amp) but it would never have to be larger than the tap conductors itself.
 

Strife

Senior Member
Thank you Dennis.
What I meant as far as location was if I can make the splices inside the existing disconnect? or do I need a J box?

The tap can occur anywhere. Look at 250.122 (G) for the EGC. It should be sized to the larger (90 amp) but it would never have to be larger than the tap conductors itself.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Thank you Dennis.
What I meant as far as location was if I can make the splices inside the existing disconnect? or do I need a J box?
You can splice in the disconnect if you have the room-- no problem. That is why I said you can make the tap anywhere. :thumbsup:
 

maghazadeh

Senior Member
Location
Campbell CA
You can splice in the disconnect if you have the room-- no problem. That is why I said you can make the tap anywhere. :thumbsup:

So far you are okey with the tap as Dennis meantioned above.
But your feeder is too small for both equipment to run at the same time, (specially for in rush current).
May be you can add a double through disconnect ahead of first disconnect to choose which equipment can be energized at one time.
 

Strife

Senior Member
I thought it was the combined load plus 25% of the highest? (40+24+10=74A). Which would apply even on a demand factor application. And the 25% is for continuous load, which hardly applies here.
Keep in mind that I'm talking about about a baler and trash compactor which both run for about 30 seconds at full cycle and are being used MAYBE 2 times an hr(not even at same time).

So far you are okey with the tap as Dennis meantioned above.
But your feeder is too small for both equipment to run at the same time, (specially for in rush current).
May be you can add a double through disconnect ahead of first disconnect to choose which equipment can be energized at one time.
 
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