Something went wrong!!!

Status
Not open for further replies.

Eduardo Maun

Member
Location
Qatar
Sir,

Good morning, We have existing panel the main breaker rated 200A and sub-main/branch rated (2) 100A & (1) 63A. My Engineer suggest to add (2) 100A. I told him this will overload our main breaker but he insist that it is safe to add additional (2) 100A. How can I calculate the max. load of the main breaker can withstand. Or my Engineer is correct to add (2) 100A in the panel?

My Engineer told me I need to know the total connected load and if the total connected exceed to 200A that's the time main breaker will overload. Well he is more experience most likely he is correct. What about the cable size in the existing panel should I need to upgrade it? and the service entrance from meter to main panel?

Twoskinsoneman
Senior Member
Your engineer is right. Adding CBs and sub-panels is not important. What is important is doing a load calculation to determine if the service is sized correctly or requires upgrading.

For a period of two weeks the wire from load to sub-main panel burned and we are lucky because it did not create more damage. I ask my Engineer you told me nothing will happened if we add additional load and it is safe. Now he wants me to change the wire size I'm afraid this will cause more damage and I think it will be a temporary solution but because my Engineer got more experience than me I need to follow him even if I don't agree with him... LOL...I suggest why not call the Power Utility Provider to find out what is really the problem. If the (2) breaker for additional load cause the problem or it will create problem in the future. By the way 2 breaker rating 63 amp & 80 amp.

Thank you.
 

Twoskinsoneman

Senior Member
Location
West Virginia, USA NEC: 2020
Occupation
Facility Senior Electrician
Eduardo,

There appears to be a small language problem keeping your situation/questions a little difficult to understand. If you want educated opinions please post a better description and drawing of your setup with wire/CB sizes and known loads. Both your engineer and myself suggested a load calc was needed before adding a heavy load. Adding a large load without one is irresponsible.
 
Status
Not open for further replies.
Top