Flexible Connection to a Chiller VFD

[tlholloway]

IS there a requirement to install a flexible connection to a Chill water VFD control cabinet.
Chiller weighs 20,000lbs. Weld pipe and fittings bolted to it.

I ran conduit from panel to VFD, Is there a requirement if there is no vibration, on said conduit??

 

[infinity]

Basically it's a judgement call. We would use a flexible connection. Is the chiller mounted on some sort of vibration eliminator?

 

[tlholloway]

1/8" rubber pads is what it sits on.

 

[infinity]

1/8" rubber pads is what it sits on.

Then IMO it can be hard piped without a flexible connection. I don't think that the NEC ever requires a flexible connection to a chiller. It mentions using flexible raceways and cords to prevent the transmission of vibration but I cannot find where that's required.

 

[tlholloway]

Thank You for your time.

 

[ron]

It might be a good idea to use flexible conduit to avoid transmitting vibration, and it is allowed by Article 348 and 350, but it is not required.

 

[Jraef]

Just be aware that with VFD motor leads, you must EITHER use shielded VFD cable, or use steel bonded conduits to accomplish magnetic shielding. So if you want to use LFNMC, the cable inside should be the shielded VFD cable, with shielding grounded on both ends.

 

[tlholloway]

My apologies.

This sis the Feeder wire from a Switch board, nothig to do wit controls, thank you

 

[infinity]

My apologies.

This sis the Feeder wire from a Switch board, nothig to do wit controls, thank you

Thanks for clarifying. So the same question remains, is a flexible connection required for the feeder raceway to terminate on the chiller?

 

[tlholloway]

No requirements i have seen. Code doesnt require it. I know it is an industry standard to use flex or LFNMC. But just wanted clarification.