Elevator breaker sizing

[Imp766]

We are in the process of up grading our elevator controls here at a small rural healthcare facility.

We are installing a new pump and controls for the elevator.
The hydraulic submersible pump for the elevator is a 20 hp, 3 ph, 208 volts.

The calculations for sizing the breaker for this come to around 147 amps, which rounded up to the next size is 150 amps.

The control panel states 80 amp service. So what is the proper sizing for this?

The elevator tech states that the 150 amp is too big, he suggested 125 amps.

Also, the breaker for the equipment is within 50' of the controls, so do we need a separate disconnect by the elevator equipment?

 

[nakulak]

its been my personal belief based on my experiences that its always a good idea to get the elevator shop to give you the power requirements for the particaular elevator (in writing). they usually know what their equipment requires, especially if there are any power conditioning problems also.

 

[W6SJK]

Does your facility have fire sprinklers? If so you may need a shunt trip CB and related wiring to trip it upon alarm of a heat detector installed within 2' of the sprinkler head if you don't have that already. Then there's the smoke detection for elevator recall if not existing. The elevator mfr will require a fusible disconnect for the controller and another for the car ltg, and a GFI receptacle in the machine room. Finally, the mfr of last elevator project I had required a full size gnd - i.e. same as phase wires. You may have all this... just FYI in case you don't.

 

[Pierre C Belarge]

its been my personal belief based on my experiences that its always a good idea to get the elevator shop to give you the power requirements for the particaular elevator (in writing). they usually know what their equipment requires, especially if there are any power conditioning problems also.

This is a very good suggestion.

 

[MNWildcat]

This is a very good suggestion.

I agree and over the years I have always tried to have the elev manf size the fuses, but recently that are defering that back to me since I am the engineer and they are only the manf. My take is they are the manf and know the RLA and inrush much better for that particular application.

 

[W6SJK]

One nice feature I've seen lately is that they are using soft start controllers with 2x to 5x adjustable inrush.