Is a disconnect after harmonic filter required? 1

[AJ2002]

I am working on a electrical chiller replacement job. It involves replacing an constant speed chiller with a VFD chiller. I planned on using the existing CB to feed a new harmonic filter physically inplace of the old motor starter(adjacent to existing powerpanel) and then connecting the filter to the unit mounted VFD w/CB.

An engineer says this is a violation of the NEC 25 FT Tap rule because the cables are 30 FT and a disconnect is required after the filter.

The filter consists of a two series reactors with a capacitor bank tapped after the first reactor. There is no electrical isolation, like a transformer. I am considering this filter integral to the dedicated branch circuit and not a tap rule application, therefore, no disconnect is required.

All the cabling is sized for full load. Which view correct??? Help is greatly appreciated.

 

[rbulsara]

I would say your view is correct. I have run into electrical inspector requiring a local (within sight) disconnect on "line" side of a reactor, citing safety for maintenance, but not on the secondary side.

It is not a seperately derived source so secondary side disconnect is not required, as it would be in case of a transformer.

 

[AJ2002]

Thank you for the response rbulsara.

 

[resqcapt19]

It is not a seperately derived source so secondary side disconnect is not required, as it would be in case of a transformer.

Transformers are not required to have a means of disconenct at the secondary. The may be required to have secondary overcurrent protection, but that can be located anywhere. The secondary conductors, will however, in most cases, require overcurrent protection at or near the transformer.
Don

 

[rbulsara]

resqcap:

You are correct in interpretation of the Code.

I figured that was the intent of "other" engineer that OP referred to,as a tap rule was mentioned. Conductors need to be protected at the origin and a separately derived source (tranformer) would be a new origin but not a reactor.