OCPD for sump pump controller with 2 pumps

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cppoly

Senior Member
Location
New York
Is a branch circuit OCPD for two pumps (fed through a controller) sized differently depending on whether the pumps start at the same time or not? Because I can’t find this requirement in 430.53.

For instance, if you have two sump pumps that do not start at the same time that are 208V, 3 phase, 1 HP (4.6 FLC), the OCPD should be sized 2.5 x 4.6 = 15 AMP OCPD + 4.6 amps = 15 AMP OPCD (round down). If they start at the same time I would think the OCPD would be 4.6x2 = 9.2 amps x 2.5 = 23 amps = 20 amps OCPD.

Thoughts?
 

SceneryDriver

Senior Member
Location
NJ
Occupation
Electrical and Automation Designer
Is a branch circuit OCPD for two pumps (fed through a controller) sized differently depending on whether the pumps start at the same time or not? Because I can’t find this requirement in 430.53.

For instance, if you have two sump pumps that do not start at the same time that are 208V, 3 phase, 1 HP (4.6 FLC), the OCPD should be sized 2.5 x 4.6 = 15 AMP OCPD + 4.6 amps = 15 AMP OPCD (round down). If they start at the same time I would think the OCPD would be 4.6x2 = 9.2 amps x 2.5 = 23 amps = 20 amps OCPD.

Thoughts?

What does the data sheet / name plate for the pump controller call for? 15A or 20A?

If you're designing the control panel, you pretty much get to pick.

Does it really matter? The cost difference between #14 and #12 wire is negligible. Run #12 wire, and install the desired breaker later if you can't call it out on a drawing right now.



SceneryDriver
 

david luchini

Moderator
Staff member
Location
Connecticut
Occupation
Engineer
Is a branch circuit OCPD for two pumps (fed through a controller) sized differently depending on whether the pumps start at the same time or not? Because I can’t find this requirement in 430.53.

For instance, if you have two sump pumps that do not start at the same time that are 208V, 3 phase, 1 HP (4.6 FLC), the OCPD should be sized 2.5 x 4.6 = 15 AMP OCPD + 4.6 amps = 15 AMP OPCD (round down). If they start at the same time I would think the OCPD would be 4.6x2 = 9.2 amps x 2.5 = 23 amps = 20 amps OCPD.

Thoughts?

430.53(A) says that the branch circuit shall not be over 15A.
 
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