Motors
- Thread starter LincHawk
- Start date
- Status
ptonsparky
Tom
- Occupation
- EC - retired
Twenty seven an a half. You are missing too many details y
tp @nswer.
tp @nswer.
There are provisions in NEC for multi motor arrangements. I’ve seen over a dozen driven off a single VFD. You need individual overload relays but they can share one short circuit protection and one VFD or contactor.
Used to be common to run DC motors with parallel fields and series armatures. This combination causes them to naturally load share. They can also series with generators in a Ward Leonard loop. Course these days what I’m saying might be foreign to anyone who hasn’t worked on large variable speed systems that were installed before power electronics.
It’s common with any kind of a traction system (cranes) or equipment on rails to use multiple motors per drive. Also mixers and various systems that have a ribbon or web of material under tension. Also pumps, conveyors, and excavators where total power gets into several thousand HP where it makes sense to run load sharing over several smaller motors.
Used to be common to run DC motors with parallel fields and series armatures. This combination causes them to naturally load share. They can also series with generators in a Ward Leonard loop. Course these days what I’m saying might be foreign to anyone who hasn’t worked on large variable speed systems that were installed before power electronics.
It’s common with any kind of a traction system (cranes) or equipment on rails to use multiple motors per drive. Also mixers and various systems that have a ribbon or web of material under tension. Also pumps, conveyors, and excavators where total power gets into several thousand HP where it makes sense to run load sharing over several smaller motors.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
There are specific rules in article 430 the NEC for having multiple motors on one circuit, you need to read through that article for issues regarding conductor sizing, disconnect sizing, short circuit and overload protection. But yes, you can.
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
You can put as many as you want. If you put fused disconnects on all the motors your "branch circuit " becomes a feeder, size accordingly. And your branch circuits are the disconnects, feeder taps and load side from the disconnects to the motors. You need motor starters, drives or some type of overload protection for the motors
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