Delta Secondary load

[Electriceel]

A 3 phase bank, 240 volt delta secondary, lighting tub is 100 kva, the wing tubs are 50 kva. Serves approximately 8 customers in a business district situation
What would you consider to be an overload situation?

Had 175 amps on 120 leg, 150 amps on other 120 leg, wild leg 20 amps.

I would estimate the tubs to be only 1/2 loaded at the time we checked.

[trigger]

Not even close unless the leads are too small. At least 750 mcm on lighter

[davis.lineman]

If you ever have a doubt there is always the old rule of thumb you can go by out in the field. you take your KVA rating and multiply that by 1000 and then divide it by your secondary coil voltage. it being a delta secondary you would use the full coil rating voltage of 240 on a 120/240 connection. now if you parallel your secondary coils then you double your ampacity. so you would divide it by half your coil voltage so on a 120/240 parallel you would only divide it by 120 thus doubling your load. now remember this is just a quick rule of thumb if you ever doubt. these aren't exact. you have a lot more factors involved.

this is why most often on your wye configured banks whether its overhead pots or a padmount tub you will see a lot more available fault current on it. you can ask your engineers too. there is always ego involved but you can learn a lot from asking a few simple questions.