Industrial Design basic question

[sfav8r]

A friend of mine owns a machine shop. They are moving to a smaller space that only has 400a 3Phase (existing is 800a). They are getting rid of some equipment but are still concerned that they will not have power to meet code calculations. I was thinking that they could put two pieces of equipment that are never needed at the same time onto contactors controlled by a 3-way switch so that only one piece of equipment could have power at one time. Does anyone know if this is satisfactory for load calculation purposes? We mostly do resi.

Thanks

 

[don_resqcapt19]

See 220.60.

 

[Gary11734]

See 220.60.

I looked at 220.60.

I was thinking; If I try to permit this, would the AHJ want to show an interlock on the equipment that both would never be on at the same time?

 

[sfav8r]

I looked at 220.60.

I was thinking; If I try to permit this, would the AHJ want to show an interlock on the equipment that both would never be on at the same time?

Gary,
That was the point of the 3-way switch and contactors. Power would only be delivered to one machine at a time.

Thanks for the code reference Don, that sounds pretty clear to me.

 

[Gary11734]

Gary,
That was the point of the 3-way switch and contactors. Power would only be delivered to one machine at a time.

Thanks for the code reference Don, that sounds pretty clear to me.

Yes, great idea. I would put that on the drawing if I was going to permit.

And, it takes care of 220.60...

 

[kwired]

Can you get demand data from old location, and then somehow factor in whatever differences there may be from one facility to the other? This sort of assumes you will move nearly all equipment and use it in similar load patterns. HVAC and lighting maybe main differences but if a smaller facility you can somewhat assume they will be less. After that if you are not even close to too much load for what is available it should be fine, if you are close you need to study harder to figure things out.