Calc Question

A

Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
Think I have a big problem. I hope not. They want me to feed 100A guard booth panel from the 60A LP-1. I did not bring over a 100A feed. I only brought over circuits for the 7.9A FLA but those are for the full load amp for the branch circuits.

Do I really need to run over a 100A circuit? Also I don't think the 60A panel would have enough power.


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View attachment 2575534
 
If your feeder supplying the panel is protected by a 60 amp breaker it does not matter what size (rating) panel you have at the guard booth (60 amp, 100 amp, 200 amp, etc.)
With a 7.9 amp load why would you think a 60 amp would not be enough ?
 
Alwayslearningelec said:
I only brought over circuits for the 7.9A FLA
Click to expand...
Not sure what this means? Did you bring a 3Ø, 60 amp feeder to the panel as per your drawing? Also your first graphic is for a 1Ø, 120/240 volt panel. Is this the same panel in both graphics they appear to be different?
 
I only brought over one 30A circuit to each guard booth. I was worried when I say the guard booth panel was rated at 100A thinking I needed to run a 100A circuit to the panel.
 
Alwayslearningelec said:
I only brought over one 30A circuit to each guard booth. I was worried when I say the guard booth panel was rated at 100A thinking I needed to run a 100A circuit to the panel.
Click to expand...
You posted two different graphics which one is correct? A 30 amp circuit probably isn't going to work the LP-1 in the second one.
 
The 1st pone with the 7.9A is the panel in the guard booth. The other 60A panel(LP-1) is what they want to feed the guard booth panel. They don't show the circuits from LP-1 to guard booth but just say to use spare circuits.
 
Shows 5 heat trace circuits, but no load calculation included for them. Most guard shacks I'm familiar with have a window A/C or a fan at a minimum?
 
Alwayslearningelec said:
The 1st pone with the 7.9A is the panel in the guard booth. The other 60A panel(LP-1) is what they want to feed the guard booth panel. They don't show the circuits from LP-1 to guard booth but just say to use spare circuits.
Click to expand...
Got it, so the second graphic is irrelevant to the discussion. Since the panel is fed from 208 volts source and not a 240 volt source their calculations in the first graphic could be slightly off.
 
infinity said:
Got it, so the second graphic is irrelevant to the discussion. Since the panel is fed from 208 volts source and not a 240 volt source their calculations in the first graphic could be slightly off.
Click to expand...
As long as I don't need to bring 100 circuit that panel with only two circuits and total 7.9FLA.
 
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