[shas595]

Hello all,

potentially dumb question here. I am thinking about moving the business, and I currently have about 20 CNC machines. When I am looking for a building, how do I calculate how much power I need? Is it the kVa that is specified in the manuals, or the Fused Amperage? (For instance, a Hitachi Seiki Hicell 30 says power required is 32Kva, 125A Fused). Also, if the building has 800A service three phase, is it 800A per leg?

Thanks!

[cgo]

Power Calculator for Generators: Convert kVA to kW, kW to kVA, kW to HP

This link has just what you need to figure out your needed power.

Yes 800 amp per leg for 800 amp 3 phase service.

Dont forget power for other things like lighting, air compressors , hvac and misc, those will also require power and add up fast.

[underthetire]

You simply need to look at the back of the machines on the tag and see what the full load amperage is, FLA should be listed on all tags. Add those together with all your support equipment and see if you have enough. Also, word of caution that will get a lot of people, and can be very expensive-Make sure all building inspections are done BEFORE you move in equipment. Ive seen more than one time the building inspector comes in to a shop for inspection, then finds all the equipment not UL or whatever he is looking for approved, then makes the customer get all his machines approved before sign offs. That usually is 4-8K per machine! Those that waited to move in equipment never got dinged.

[shas595]

You simply need to look at the back of the machines on the tag and see what the full load amperage is, FLA should be listed on all tags. Add those together with all your support equipment and see if you have enough. Also, word of caution that will get a lot of people, and can be very expensive-Make sure all building inspections are done BEFORE you move in equipment. Ive seen more than one time the building inspector comes in to a shop for inspection, then finds all the equipment not UL or whatever he is looking for approved, then makes the customer get all his machines approved before sign offs. That usually is 4-8K per machine! Those that waited to move in equipment never got dinged.

Good to know, will definitely have this done. I just spoke with guy who used to work for Hitachi, and he told me the kVa rating was the max load the machine could require with all options running at max output. So his suggestion was to add up all the kVa for the machines, multiply by 20% and then halve the result. This way you are leaving a cushion, but not spending crazy money to get power you will never use. We never have more than 10 CNC on at a time, and never running full blown at that. Sound like a good plan?

John

[newlife]

Are you planning for growth? Easiest growth will be adding manpower on existing equipment, so if you at can fully man the equipment load you have this will require closer to all machines at 80 to 100% of FLA. It is awfully expensive to add power capacity later. Just a thought