Adjustment Calculation

A

Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
Hello, am I calculating this correctly.

Not considering VD.

I want to possibly combine DOAS ckts 1,3,5- 2,4,6-7,9,11

After adjustment/corrections for CCC’s I come up with following wire sizes needed.

Ckt 1,3,5 = #6 THHN

Ckt 2,4,6 = #4 THHN

Ckt 7,9,11 =#12 THHN

Is this correct. Now have to size the conduit..I’m guessing 2” EMT.

1705495612319.png
 
Alwayslearningelec said:
Hello, am I calculating this correctly.

Not considering VD.

I want to possibly combine DOAS ckts 1,3,5- 2,4,6-7,9,11

After adjustment/corrections for CCC’s I come up with following wire sizes needed.

Ckt 1,3,5 = #6 THHN

Ckt 2,4,6 = #4 THHN

Ckt 7,9,11 =#12 THHN

Is this correct. Now have to size the conduit..I’m guessing 2” EMT.

View attachment 2569556
Click to expand...
Impossible to say. We don't know the unit MCAs.
 
Your derating calculations are correct. 1.5" EMT allows 10-#4's so that would work.
 
JoeStillman said:
Load calcs using MCA are inaccurate. For multi-motor equipment (like a DOAS) you need the RLA or FLA of each motor.
Click to expand...
He's not asking about load calcs. He's asking about conductor ampacity. Need to know the minimum circuit ampacity to see if ampacity calculations are correct.
 
david luchini said:
He's not asking about load calcs. He's asking about conductor ampacity. Need to know the minimum circuit ampacity to see if ampacity calculations are correct.
Click to expand...
If there is an MCA involved his conductors might even be larger than necessary. If you just use the OCPD size his numbers are correct.
 
david luchini said:
I've got to believe that #14 would be adequate for the smallest unit.
Click to expand...
Where we are, #14AWG isn't allowed in commercial applications.

Although I don't disagree with your thought process, I think Infinity has the better way of looking at it.
 
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