Generator tap

tdebrum

Member
Location
Lakeville,MA.USA
Occupation
Retired power plant electrician,MA, Journeyman Electrician
Nec Tap rule 240.21:
26000kw stand-by generator with 125 amp breaker @ generator ,feeds 200 amp # 1 transfer switch in house 20 feet distance,than tap at # 1 transfer switch to # 2 ,200 amp transfer switch (in house)80 feet away, conductors in conduit, would this be against 240.21
445.13(B) reverts back to 240 .21
Install, OCPD at the tap point for conductors longer than 25 feet ,would this satisfy tap rule?
Or is this not feasible.
 
Tap would be at 1ats and than to 2nd ats, tap would not be at generator, ats that feeds 2nd panel is lightly loaded.
 
I’m not seeing where or how you have a tap.

Going from a 125A OCPD to a 200A and then another 200A (assuming those have OCP), with #3, I’m just seeing an undersized conductor.

Unless you have a 100A OCP somewhere, I don’t see a tap.
 
Sorry gave wrong info,
26000kw stand-by generator (load shedding)(Propane)has 125 amp breaker on it,produces 108 running amps ,the house a has 2 ,200 amp panels they are approx 80 feet apart ,one on each end of house fed from one meter.
The generator (20 feet from #1 switch)will feed transfer switch # 1 at 200 amp panel # 1 and Tap at # 1 transfer switch to feed # 2 transfer switch at # 2, 200 amp panel, using #2 cu wire,both panels have OCPD, trying to satisfy Tap rule,
Hope this makes sense.
 
The rule specifically addresses situations where a smaller conductor is tapped into a larger feeder conductor, potentially for a branch circuit or sub panel.

Got it. Thank you all
 
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