Fire pump Equipment Grounding Conductor

[don_resqcapt19]

But if someone places the dial of the motor controller factory installed internal breaker to 1200A (20x full load amps) then sizing based on 400A would be not correct.

Do fire pump motor controller internal breakers have dial or is it factory set so no one can tamper with it? If factory set then what is it the setting set at 6x fla or 20x fla?

No matter what the downstream instantaneous setting is, you can't flow more current than the upstream 400 amp device will permit.
In addition, if that is the only dial, the device is an instantaneous trip device and 250.122(D)(2) would apply.

 

[infinity]

Breaker is 80A frame and its tripping setting go from 360A to 1200A.

What kind of controller is this?

 

[hhsting]

No matter what the downstream instantaneous setting is, you can't flow more current than the upstream 400 amp device will permit.
In addition, if that is the only dial, the device is an instantaneous trip device and 250.122(D)(2) would apply.

Would not the fire pump controller isolate the upstream breaker so that current flow on line side is Not the same on load side?

 

[infinity]

Would not the fire pump controller isolate the upstream breaker so that current flow on line side is Not the same on load side?

How is that possible?

 

[hhsting]

How is that possible?

Is it possible or not is my concern? I just dont know

 

[roger]

Is it possible or not is my concern? I just dont know

Sorry but if you don't or can't grasp this you should let someone else in your firm review this.

Roger

 

[mbrooke]

Is it possible or not is my concern? I just dont know

Series fault impedance, no auto transformer involved so what the controllers sees the 400 amp fuses will so.

If you give me the run lengths from the MDP to the fire pump and the kva of the POCO transformer I can run some rough numbers for you.

 

[roger]

Series fault impedance, no auto transformer involved so what the controllers sees the 400 amp fuses will so.

If you give me the run lengths from the MDP to the fire pump and the kva of the POCO transformer I can run some rough numbers for you.

So I suggest you take mbrooke up on the offer.

Roger

 

[don_resqcapt19]

Would not the fire pump controller isolate the upstream breaker so that current flow on line side is Not the same on load side?

There is nothing in the controller that creates energy or power, so how could there be more energy or power on the load side of the controller than on the line side?