Hello,

I am checking to see if the panelboard in the old building can handle my load
(considering a restaurant in this building)

The old square-D panelboard label reads:

Power <<<< >>>> lights
------------------------------------
90 << bus amp>> 175
120-240 << bus volts >> 120-240
3-ph 4 w <<phase>> 1-ph 3 wire
60 <<cycles>> 60

There is also a B-stinger service for an old (unused) elevator

Question: how much current I can draw from this panel?
My equiment requires 200A 110V

Thank you

So do you have a 90 amp 120/208 volt 3 phase panel and a 175 amp 120/240 volt single phase panel?

That's what I get from:
90 << bus amp>> 175
120-240 << bus volts >> 120-240
3-ph 4 w <<phase>> 1-ph 3 wire

Not sure what a B-stinger service is.

How did you arrive at your equipment needs 200 amp 110volt? Did you add the load for each appliance to arrive at a total of 200 amp?


Are you sure you do not have any 208 volt 3 phase or 240 volt 1 phase restaurant equipment? I have done many restaurants and even the smallest one has something 208-240 volts.

Can you help with more detail and answer my questions and we can go from there.

Generally speaking, the load is added to arrive at a total connected load, and increase that by 25% to arrive at the panel or service size.

Thanks

So do you have a 90 amp 120/208 volt 3 phase panel and a 175 amp 120/240 volt single phase panel?

Hello, here are some more details,

Not sure what a B-stinger service is.

Reply>> B-stinger is a center tapped delta secondary of the transformer that reads 240 to ground, other two phases read 110 to ground (also known as dog-leg) - found in older buildings.

How did you arrive at your equipment needs 200 amp 110volt? Did you add the load for each appliance to arrive at a total of 200 amp?

Reply>> I added everything + 25% of total + 25% of largest load


Are you sure you do not have any 208 volt 3 phase or 240 volt 1 phase restaurant equipment? I have done many restaurants and even the smallest one has something 208-240 volts.

Reply>> correct, I do not have anything that needs 208/240V, the stinger leg (240v) was used for on an old elevator that since has been taken out of service

I would like to know what total current I can reasonably get out of this panel, one electrician said I don't need a new panel, other said I do, the city inspector said "you might",

Thank you

Ok, wow have not run into this for a long while, we call it the "bastard" leg. I suppose b-stinger is more socially acceptable.

So is the delta panel the 175 amp? Or the 90? I am still a bit confused about which panel is which.

Obviously, as you probably know,you cannot use the B phase on the delta panel for any 120 volt circuits.

FYI, the center leg should colored orange.

Derate each leg or phase of each panel by 80%, and that is what is allowed for load. If this helps, great, if not get back with more questions.