Optional standby systems 702.5 confusion

[mjmike]

Ok, have a question regarding 702.5.B.2 regarding non life-safety generator and an ATS. To put this in non-specific terms, there are 3 motors of type A and 2 motors of type B. Under normal power conditions, 1 type A motor and 1 type B motor is a standby backup motor. This load will never run unless a motor drops out for some reason. The normal service size is based on this loading. This will be the same situation under an emergency condition. The mentioned article is confusing me. Even thought the motors will never run, do all the motors need to be included in the generator sizing? I interpret the full load as the max demand. Since 1 type A motor and 1 type B motor are standby only, they do not need to be counted. Heck if you have 20 of these configurations, then the generator could end up being double the service size and panels / wires could end up being larger after the ATS then befor the ATS.
Here are some alternative I also thought of:

1. The mptprs are powered from a motor control panel. could this be considerdd "Load management under 702.5.B.2.b?

2. Because the control panel is sized for the indicated motor load, even though there are additional standby motors, could the "load" on the generator be the control panel which is UL built and sized?

Just some thoughts.

 

[iwire]

Size the generator for the connected load just like you would for anything else and we never have to count Noncoincident loads.

220.60 Noncoincident Loads. Where it is unlikely that
two or more noncoincident loads will be in use simultaneously,
it shall be permissible to use only the largest
load(s) that will be used at one time for calculating the total
load of a feeder or service

 

[LEO2854]

Ok, have a question regarding 702.5.B.2 regarding non life-safety generator and an ATS. To put this in non-specific terms, there are 3 motors of type A and 2 motors of type B. Under normal power conditions, 1 type A motor and 1 type B motor is a standby backup motor. This load will never run unless a motor drops out for some reason. The normal service size is based on this loading. This will be the same situation under an emergency condition. The mentioned article is confusing me. Even thought the motors will never run, do all the motors need to be included in the generator sizing? I interpret the full load as the max demand. Since 1 type A motor and 1 type B motor are standby only, they do not need to be counted. Heck if you have 20 of these configurations, then the generator could end up being double the service size and panels / wires could end up being larger after the ATS then befor the ATS.
Here are some alternative I also thought of:

1. The mptprs are powered from a motor control panel. could this be considerdd "Load management under 702.5.B.2.b?

2. Because the control panel is sized for the indicated motor load, even though there are additional standby motors, could the "load" on the generator be the control panel which is UL built and sized?

Just some thoughts.

If im reading your post right the source only has to be large enough for the connected load.

 

[mjmike]

That is wat I thought, but the 702.5.B.2 had me a little confused. Thanks for the clarification.