Max fuse size / max OCPD

[cppoly]

If an AC unit specifies max fuse size of 15A, is there any restriction on feeding the 15A fuse from a panel with a 15A C.B. as well?

 

[Dennis Alwon]

No problem but are you sure the unit states max fuse and not max fuse or breaker?

 

[cppoly]

Ok thanks. Yea, why are these no longer typically specified?

 

[Dennis Alwon]

Ok thanks. Yea, why are these no longer typically specified?

What is not specified? I don't understand.

Typically you don't see Fuse Only on the units except for commercial units or older residential units. Fuse tend to react faster then breakers I believe but I am not sure why that is so important with some units.

 

[cppoly]

I was asking if fuses are not typically specified with AC units for required overcurrent protection. Thanks.

 

[augie47]

95% or more of the A/C units I inspect will allow fuse or HACR circuit breakers for the MOCP per the manufacturer specs. Ofter-time the use of a breaker is a (*) footnote.
Most of the walk-in coolers and freezers units i inspect are "Fuse" or "Fuse Only".

I'd say on commercial jobs the drawings I see are 50/50 fusible or non-fusible disconnects. Some contractors use fusible ones to facilitate quick adaption in the event the new units arrive specifying other size OCP than expected.