Elevator Feed and OCP

[Kramslod]

I am currently working on a project in which 2 elevators are being installed. They are identical elevators. I have been given the following information on them: 208 volt 3 phase 236 amp starting current and 114 amp full load current. There will be a shunt trip breaker installed in the MDP for each of the elevators. There will also be a fused disconnect in each of the (2) elevator machine rooms. Elevator #1 is only 50 feet from the MDP while elevator #2 is 350 feet from the MDP.

My question is this; How do I size my feeder conductors, shunt trip breaker and fuses.

I read several other threads on motors and OCP, but became a bit confused regarding conductor sizing and OCP. I am also doing an elevator which has table 430.22 (E) thrown into the mix.

I am sure I could just throw this over to the electrical engineer, but I would very much like to learn as much about this as I can for my own edification.

Thanks in advance for any help.

 

[chris kennedy]

My question is this; How do I size my feeder conductors, shunt trip breaker and fuses.

Feeders 620.13 which sends you to 430.22. OCP 620.61 sends you to 430.33

I am also doing an elevator which has table 430.22 (E) thrown into the mix.

Most motor applications are continuous duty, meaning they operate at a constant load for an indefinitely long time. For motors that are not continuous duty, the motor nameplate currents and Table 430.22(E) are used to determine the branch-circuit ampacity. A motor is considered to be for continuous duty unless the nature of the apparatus it drives is such that the motor cannot operate continuously with load under any condition of use. Conductors for a motor used for short-time, intermittent, periodic, or varying duty are required to have an ampacity in accordance with Table 430.22(E). Branch-circuit conductors for a motor with a rated horsepower used for 5-minute short-time duty service are permitted to be sized smaller than for the same motor with a 60-minute rating, due to the cooling intervals between operating periods. For example, a 5-minute rated motor will run for 5 minutes and then be off for 55 minutes. The terms continuous duty, intermittent duty, periodic duty, short-time duty, and varying duty are defined in Article 100.

Welcome to the Forum

 

[Kramslod]

Thanks for the information, but I am still unclear as to whether the conductors can be rated for the Full Load Current and the OCP rated for the Startup or if the conductors need to be sized according to the OCP.

 

[Kramslod]

Can anyone else offer some input?