VAV FSS

[shaw0486]

Hi,
I was wondering why engineers always show VAV with Fused safety switches when almost all VAVS are equipped with fuse blocks internal from the manufacturer. Am I missing something or should just a standard disconnect be required if the unit is not provided with one?

 

[iwire]

It depends on the units labeling and the circuit supplying it.

If the unit says 15 amp circuit and breaker at the panel is larger than that a fused disconnect is a way to deal with that.

 

[shaw0486]

for instance if a VAV says max fuse or HACR circuit breaker 6 amps. and the unit is equipped with a 6 amp fuse block would you think the code says this requires external protection? ie fused safety switch/circuit breaker?

 

[ptonsparky]

for instance if a VAV says max fuse or HACR circuit breaker 6 amps. and the unit is equipped with a 6 amp fuse block would you think the code says this requires external protection? ie fused safety switch/circuit breaker?

Depends on which label states 6 amps. The label on the outside of the unit with all the info an electrician needs says 6 amps then Yes. Label on the inside of the unit cover for the service tech, No.