Have to use fused disconnect if the walk-in freezer compressor name plate state "Max. Fuse Size"?

[jap]

That label doesn't say a fuse is required.

It indicates Maximum Fuse size of 35 amps.

If the max fuse size is not needed, why would one be held to installing a fuse at all?

JAP>

 

[retirede]

That label doesn't say a fuse is required.

It indicates Maximum Fuse size of 35 amps.

If the max fuse size is not needed, why would one be held to installing a fuse at all?

JAP>

I was always taught that “Max fuse size” means a fuse is required.

If it said “Maximum OCPD”, would you think that no OCPD is required if you didn’t need the max?

 

[mtnelect]

This might help ... see foot note.

 

[mtnelect]

Serial Number: 33AM2821 = Assemble in Mexico, Week 28, Year 2021

 

[jap]

I was always taught that “Max fuse size” means a fuse is required.

If it said “Maximum OCPD”, would you think that no OCPD is required if you didn’t need the max?

The breaker feeding the disconnect takes care of the OCP part of it.

If you have a 30 amp breaker feeding the disconnect for the OP"s unit you wouldn't have met the max fuse size of 35 amps.

So why would a fuse be needed?

JAP>

 

[infinity]

I was always taught that “Max fuse size” means a fuse is required.

If it said “Maximum OCPD”, would you think that no OCPD is required if you didn’t need the max?

That's what I had been taught too but where in the NEC does it say that?

 

[don_resqcapt19]

That's what I had been taught too but where in the NEC does it say that?

It gets down to 110.3(B) and the product standard for the equipment. The product standard requires that the type and maximum size of OCPD be on the nameplate. Where the type of OCPD shown on the nameplate is a fuse, you are only permitted to use a fuse.

I have not seen one with that marking in a long time. Typically that marking predates the HCAR breakers which have been around for at least 3 decades now. It has to do with the protection of equipment that has multiple motors, and standard breakers did not do a good job with that.

When the HCAR breakers first came out, the name plate marking would often say "fuse of HCAR breaker". Now most just say OCPD because all listed breakers are HCAR breakers.

 

[jap]

It gets down to 110.3(B) and the product standard for the equipment. The product standard requires that the type and maximum size of OCPD be on the nameplate. Where the type of OCPD shown on the nameplate is a fuse, you are only permitted to use a fuse.

I have not seen one with that marking in a long time. Typically that marking predates the HCAR breakers which have been around for at least 3 decades now. It has to do with the protection of equipment that has multiple motors, and standard breakers did not do a good job with that.

When the HCAR breakers first came out, the name plate marking would often say "fuse of HCAR breaker". Now most just say OCPD because all listed breakers are HCAR breakers.

I agree with others that mentioned more care needs to be put into the nameplates to indicate both the type and the max size.

JAP>

 

[infinity]

It gets down to 110.3(B) and the product standard for the equipment. The product standard requires that the type and maximum size of OCPD be on the nameplate. Where the type of OCPD shown on the nameplate is a fuse, you are only permitted to use a fuse.

So this is a UL standard and has nothing to do with the NEC?

 

[augie47]

So this is a UL standard and has nothing to do with the NEC?

Respectfully: With 110.3(b) involved, I don't think we can say it has "nothing to do with the NEC".
(110.3(b) is how I address the UL standard)

 

[zemingduan]

Serial Number: 33AM2821 = Assemble in Mexico, Week 28, Year 2021

Thank you for this information. I learned something!

 

[infinity]

With 110.3(b) involved, I don't think we can say it has "nothing to do with the NEC".

What I meant was there is no NEC section that uses the wording fuses only in the NEC.

 

[don_resqcapt19]

What I meant was there is no NEC section that uses the wording fuses only in the NEC.

No, that is only covered in the listing and labeling requirements.