HVAC Disconnect

[chunt984]

I have an outdoor distribution panel providing power for several HVAC units. Provided this distribution panel is within line of sight of the HVAC units, can the branch circuit breakers (HACR type) serve as the disconnecting means & fulfill code requirements? Thanks for your help.

 

[rbulsara]

Technically, yes, but use your judgment. Within sight cannot be quarter of a mile, although Code does not specify a distance limit.

The idea is safety, if you yourself were to work on that HVAC units electrical and you feel comfortable that no one will reclose the breaker while you are working on it then do so or else provide local disconnects on the HVAC units.

Besides, NEC OSHA or local inspector may have their safety interpretations or requirements.

 

[BJC]

Most service techs that work on HVAC units don't trust panels. It requires faith in things that can't be seen and that they can't be sure of.
Locals inspectors know that and even if it's technically leagle I wouldn't try to get away with it.

 

[l3city]

chunt984:

Hi there, just read NEC Art. 100 under "In Sight From (within sight from, within sight)" that section tells you specific about what is meant to have equipment "within sight" as well as the distance.
Regards

 

[resqcapt19]

rbulsara,

Within sight cannot be quarter of a mile, although Code does not specify a distance limit.

The NEC does.

In Sight From (Within Sight From, Within Sight). Where this Code specifies that one equipment shall be ``in sight from,'' ``within sight from,'' or ``within sight,'' and so forth, of another equipment, the specified equipment is to be visible and not more than 15 m (50 ft) distant from the other.

Don

 

[rbulsara]

resqcapt19:

Great. Thank you for pointing this out.

I heard about 50 feet but was not sure it is so written. (Plus I did not need a Code to tell me that)

Thank you.

 

[chunt984]

Thanks for your help, everyone. I had also heard but never seen the 50 feet requirement spelled out before...good to know.

 

[jraef]

Don't forget the issue of being able to apply a lock to the disconnect. There are accessories for breakers in panelboards that can allow individual breakers to be fitted with a small padlock, but they must be installed prior to installing the breaker or the breaker must be removed and reinstalled, which means shuting down the entire panelboard feed. I have heard of a few inspectors allowing a lockable door in the panelboard front to qualify as a lockout/tagout, but not many and it likely depends on the nature of the locking mechanism.

JRaef.com
Eng-Tips: Help for your job, not for your homework Read faq731-376

 

[dpc]

Padlocking a panelboard door closed seems like a safety hazard by itself, since it might prevent power from being removed from another circuit. I've never seen that done.

But the locking devices for panelboard breakers often leave a lot to be be desired. Local disconnects for HVAC equipment seems to be the norm, even if not specifically required by NEC.

Also, rooftop units have special requirements.

 

[BJC]

The outdoor panel may not accomidate padlocks with the door closed. That would require the door to be open when the the mechanic was working on the HVAC unit. They probably never need servicing when it's raining.

 

[resqcapt19]

dpc,

Local disconnects for HVAC equipment seems to be the norm, even if not specifically required by NEC.

Air-conditioning and refrigerating equipment requires a "within sight" disconnect per 440.14. There is an exception that permits a remote lockable disconnect, but only for industrial process cooling. If it is just ventilating equipment, then the rules in 430.102(B) apply, and unless you can comply with one of the exceptions, you need a local disconnect.
Don