ELEVATOR COORDINATION.

B

binwork91

Senior Member
Location
new york
Occupation
electrical engineer
See the one line below.

The 75A elevator fuse coordinates with the 150A XT4N breaker and the 1200A A4BQ fuse. However, the 150A XT4N and the 500A XT5N breakers do not coordinate with the 1200A A4BQ fuse.

Does this comply with 620.62?

Based on the code language, it appears to comply. However, if a fault occurs on the load side of the 500A XT5N breaker, both elevators may lose power.

My question is: Do the 150A and 500A breakers need to coordinate with the upstream 1200A fuse?

620.62 Selective Coordination​


Where more than one driving machine disconnecting means is supplied by a single feeder, the overcurrent protective devices in each disconnecting means shall be selectively coordinated with any other supply side overcurrent protective devices.
Selective coordination shall be selected by a licensed professional engineer or other qualified person engaged primarily in the design, installation, or maintenance of electrical systems. The selection shall be documented and made available to those authorized to design, install, inspect, maintain, and operate the system.
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The 500A breaker is not part of the supply to the elevator so it does not need to be considered when determining coordination.
 
Why is your fuse going to trip before the breaker? That sounds odd.

Or do you want the fuses to trip before the elevator breaker?

In theory you want the 75A fuses to trip before the 150A breaker so that only one elevator is tripped if a fault occurred load side of the fuse. If the breaker trips before the fuse than you are uncoordinated and takes out both elevators.
 
Elect117 said:
Why is your fuse going to trip before the breaker? That sounds odd.

Or do you want the fuses to trip before the elevator breaker?

In theory you want the 75A fuses to trip before the 150A breaker so that only one elevator is tripped if a fault occurred load side of the fuse. If the breaker trips before the fuse than you are uncoordinated and takes out both elevators.
Click to expand...
Yes, a 75A fuse coordinates with a 150A breaker.

The 150A and 500A breakers do not coordinate with the upstream 1200A fuse in the instantaneous trip region.
 
Your 75A elevator fuse coordinates with the 150A XT4N breaker, but are they selectively coordinated? Did you check the manufacturers tables to see that they are selectively coordinated down to 0 seconds?
 
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