elevator

[malachi constant]

460V 25 HP elevator. Single elevator. Shop drawings state NEC intermittent 30 & 60 minute rated factors can be applied. Motor nameplate rated current is 36.0 amps. Per shops switch should be 3-pole 60A with 60A dual element fuses. NEC 2008 applies.

Branch circuit conductors are sized per 620.13(A), which refers you to 430.22(A) and (E). As manufacturer states intermittent factors can be applied then 430.22(E) is the correct paragraph. The table states 90% of nameplate rating applies. 36.0 * 0.9 = 32.4A.

Per Table 310.16 you can conservatively use the 60C column which allows #8 CU, or could assume all lugs are rated 75C which allows #10 CU.

I specified #8s with a 60A fused disconnect and 60A class J fuses. This meets code and manufacturer requirements, yes?

 

[kevin]

Yes. I agree with your solution.

 

[cadpoint]

Just a motor disconnect? That's it? The first thing I'd do is look and see if your fine state has elevator rules/ codes?

You keep saying shop drawings is this the manufactures drawings or someones submittal in answer to the elevator install?

Is the elevator controller infront of the motor, is both under this same situation fused or not?

Are the cab lights shown on the drawing, granted unrelated but still part of the install....

 

[malachi constant]

Trust me, there is plenty more going into the installation than just a branch circuit and disconnect. I am very familiar with this state's elevator codes. Contractor was questioning the wire and fuse size, just wanted to make sure I had my codes & calcs straight.

 

[malachi constant]

Is the elevator controller infront of the motor, is both under this same situation fused or not?

Of the top of my head I am not sure of controller location. Both controller and disconnect are fused. I believe the contractor has installed a smaller fuse than needed, which was flagged by the inspector, which is why I'm taking a closer look at this.

I guess that gets closer to the heart of this matter. The elevator inspector has asked to see selective coordination. The contract documents require the contractor to provide selective coordination with OCP in main switchboard. The contractor is insinuating there is a design (fuse or wire sizing) error, but as far as I can tell the design is fine, just maybe the fuses need swapped out and/or the inspector needs to see some paperwork. Both those items are responsibility of the contractor per the contract documents. I'm just making sure I haven't sized something incorrectly. I think I'm in the clear though. Thanks!