good afternoon, this is my first thread so please be gentle, I am just over a year into a new company and found a possible problem with the total load on a 480/400amp lug panel protected from the switchgear off a 300A breaker. Amongst other code issues I won't get into, my concern is the existing load.(1) 70 HP, (2) 60 HP, (6)25 HP, (2) 20HP, (4)15 HP and (2)10 HP motors along with a 150A tap for a 100kW oil heater. There are a couple of smaller loads (ex fork lift battery charger, overhead door) I was a plant electrician in past jobs for 20+ years, but here I am considered the operations tech (they use a contractor) I've been commissioned to install new equipment off this panel but I know I can't. Are there any exceptions that the original installer of this panel could have used to do this? On a stretch I was considering 430.26 but even that. Before I open a can of worms, I'm I missing something here?Please advise thanks.
existing powerpanel overload
- Thread starter coxxx616
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electricalperson
Senior Member
- Location
- massachusetts
whats the new equipment going to be your going to install?
"I've been commissioned to install new equipment off this panel but I know I can't."
Unless your plant is considerably different from most with which I have had some association, this approach, though perhaps Code relevant, may also be political death.
If you have been directed to install the new equipment, I would suggest you point out your concerns, but change "can't" to "shouldn't".
Industrial folks often have a bad habit of "killing the messanger"
Load diversity is obviously the key here, and, depending on the load you are directed to add, this may well be the straw that breaks the camels's back.
Unless this is some critical operation, the worse case scenerio is a tripped 300 amp breaker, normally not a "danger". In that case, a "I expressed my concern" might be best for your future than a "I can't do as directed".
If they want to go to the expense of a load study or a recording meter to prevent the enevitable, fine.
Unless your plant is considerably different from most with which I have had some association, this approach, though perhaps Code relevant, may also be political death.
If you have been directed to install the new equipment, I would suggest you point out your concerns, but change "can't" to "shouldn't".
Industrial folks often have a bad habit of "killing the messanger"
Load diversity is obviously the key here, and, depending on the load you are directed to add, this may well be the straw that breaks the camels's back.
Unless this is some critical operation, the worse case scenerio is a tripped 300 amp breaker, normally not a "danger". In that case, a "I expressed my concern" might be best for your future than a "I can't do as directed".
If they want to go to the expense of a load study or a recording meter to prevent the enevitable, fine.
Thank you for all your replys
the additional equipmnet is (2) additional 25 hp motors for mixers, 50kW booster heater with 10 hp pump.
although the breaker hasn't tripped could be a matter of "dumb luck" with the slow down in production, all the equipment has had low demand. My understanding is all this equipment was additional from a move about 1 1/2 yrs ago.
and I agree with my wording of "can't", shouldn't is a CYA word.
thank you all again
the additional equipmnet is (2) additional 25 hp motors for mixers, 50kW booster heater with 10 hp pump.
although the breaker hasn't tripped could be a matter of "dumb luck" with the slow down in production, all the equipment has had low demand. My understanding is all this equipment was additional from a move about 1 1/2 yrs ago.
and I agree with my wording of "can't", shouldn't is a CYA word.
thank you all again
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- Semi-retired engineer
I don't know why people have such a hard time just being upfront. Tell them it could overload the breaker and cause nuisance trips. Let them decide if they want to deal with that problem before hand or afterwards.
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