Suggested solutions?

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anbm

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Motor-1 needs 50A feeder (480V,3PH, 3#6, 1#10 Ground, 3/4" EMT) and 50A/3P CB protection - circuit #1.

Motor-2 needs 15A feeder (480V, 3PH, 3#12, 1#12 Ground, 3/4" EMT) and 15A/3P CB protection - circuit #2.

Both motors are fed from same panel, the panel is located around 200' from motor #1 and 150' from motor #2.
(Both motors are located in the same area.)

We made a mistake on paper and have motor #1 fed out of circuit #2 and vice versa and contractor installed that way.

Solution #1

Swap 50A and 15A breaker location in panel, leave 50A feeder to serve motor #2.
Re-use existing conduit to motor #1 and re-pull new wires (#6, #10G) to feed it.

Solution #2

Install a j-box near motor #1 location, intercept 15A feeder and extend feeder to motor #2.

Install a j-box near motor #2 location, intercept 60A feeder and extend feeder to motor #1.


Does anyone has better solutions for this and minimize labor cost, etc? Thanks.
 
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LEO2854

LEO2854

Esteemed Member
Location
Ma
anbm said:
Motor-1 needs 50A feeder (480V,3PH, 3#6, 1#10 Ground, 3/4" EMT) and 50A/3P CB protection - circuit #1.

Motor-2 needs 15A feeder (480V, 3PH, 3#12, 1#12 Ground, 3/4" EMT) and 15A/3P CB protection - circuit #2.

Both motors are fed from same panel, the panel is located around 200' from motor #1 and 150' from motor #2.
(Both motors are located in the same area.)

We made a mistake on paper and have motor #1 fed out of circuit #2 and vice versa and contractor installed that way.

Solution #1

Swap 50A and 15A breaker location in panel, leave 50A feeder to serve motor #2.
Re-use existing conduit to motor #1 and re-pull new wires (#6, #10G) to feed it.

Solution #2

Install a j-box near motor #1 location, intercept 15A feeder and extend feeder to motor #2.

Install a j-box near motor #2 location, intercept 60A feeder and extend feeder to motor #1.


Does anyone has better solutions for this and minimize labor cost, etc? Thanks.
Click to expand...

Number one will be faster,no boxes and splices to worry about.
 
augie47

augie47

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Location
Tennessee
Occupation
State Electrical Inspector (Retired)
I see a possible flaw in the original arrangement that might alter the solution.
We really need to look at the motor HP. It's possible you have no problem. For example, a 15HP 480v motor could be wired with a #12 and protected by a 50 amp breaker and be Code compliant.
 
A

anbm

Senior Member
augie47 said:
I see a possible flaw in the original arrangement that might alter the solution.
We really need to look at the motor HP. It's possible you have no problem. For example, a 15HP 480v motor could be wired with a #12 and protected by a 50 amp breaker and be Code compliant.
Click to expand...

motor-1 fla: 24.2
motor-2 fla: 5.1
 
augie47

augie47

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Location
Tennessee
Occupation
State Electrical Inspector (Retired)
anbm said:
motor-1 fla: 24.2
motor-2 fla: 5.1
Click to expand...

In all probability it will make little difference in this case, but it might benefit you to take a look at 430.6. In most cases calculations, other than selecting overload devices, the values in the Tables (430.247-.250) are used rather than nameplate.
Using FLA numbers for conductor size and GF/SC selection can mislead you in some cases.
 
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petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
he could maybe pull the green wire out and use the emt as his egc if you wanted to get legalistic about it.

ottoh, if he left the green wire in the emt and did not connect it to anything on either end is it still an egc? or just a green pulling wire left in the emt?
 
A

anbm

Senior Member
To avoid downtime to the panel if swap breakers to be done, the owner went with option 2. Thanks all.
 
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