Disconnecting Means Location

bcorps

Member
Location
Owensboro, KY
Occupation
Engineer
I have a quite crowded Mechanical yard with 32 condensing units. The yard is just outside the main Electrical Room. The condensing unit spacing is too tight for disconnect switches at each unit (only 31 inches between rows). I considered ganging four switches at both ends of each row (units are in a 4 x 8 configuration) to satisfy the "line of sight" rule, but I am wondering if I can just feed them from panels just inside the Electrical room. If I put "lockable in off position" accessories on each circuit breaker, will this give me the "line of sight" exemption I need?

Also, the way I read the code, getting around the line of sight issue doesn't get rid of the "within 50 feet" rule. Correct?

P.S. I did consider putting the panel outside with the condensing units, but they are almost 7 feet tall, which would prevent line of sight anyway, so that's why I'm considering keeping the panel inside.
 

kwired

Electron manager
Location
NE Nebraska
Lockable disconnect not within sight is acceptable for some things, unfortunately if you read arts 430 and 440 as well as 422 where it involves appliances over 1/8 HP/300 VA carefully as there is no allowances for that in any of those articles, you must have a disconnect "within sight" of the unit.

Disconnect does not need to be a large "safety switch", though you start to get limited more to those for larger circuits. If these are small enough units operating at 208/240 you may even be able to use simple double pole toggle switch as the disconnect.
 

bcorps

Member
Location
Owensboro, KY
Occupation
Engineer
Thanks for that. Okay, then I think I will go for the "panels outside" approach.

Here is the layout I was just updated with. The first panel feeds the two left columns, and the other panel feeds the other three. Would you consider this all meeting "line of sight"?

Mech Yard.PNG
 

kwired

Electron manager
Location
NE Nebraska
can you see the disconnect when servicing each particular unit and is it within 50 feet of the unit?

short units like are typical at dwellings, this is certainly more possible than some taller higher capacity units that are out there, especially in some commercial applications.
 

bcorps

Member
Location
Owensboro, KY
Occupation
Engineer
can you see the disconnect when servicing each particular unit and is it within 50 feet of the unit?

short units like are typical at dwellings, this is certainly more possible than some taller higher capacity units that are out there, especially in some commercial applications.
These units are about 6-1/2 feet tall, so there is no seeing around them. These are within 50 feet...some just barely.
 

kwired

Electron manager
Location
NE Nebraska
These units are about 6-1/2 feet tall, so there is no seeing around them. These are within 50 feet...some just barely.
My guess is most inspectors will disallow it, and looking at art 100 definition of "in sight from" I think they are justified in rejecting it, read it carefully.
 

bcorps

Member
Location
Owensboro, KY
Occupation
Engineer
My pessimistic side is starting to agree with you, kwired. I'm going to go back to trying to fit disconnect switches in somehow. Although I'm also fighting to stay more than 6 feet from the fence, or I get to sell the expense of required fence bonding and grounding to the Architect...that's always fun.
 

bwat

EE
Location
Western PA
Occupation
EE
Lockable disconnect not within sight is acceptable for some things, unfortunately if you read arts 430 and 440 as well as 422 where it involves appliances over 1/8 HP/300 VA carefully as there is no allowances for that in any of those articles, you must have a disconnect "within sight" of the unit.
Can you clarify this for me regarding just article 430? It looks like you're saying that 430 doesn't allow remote lockable disconnect to serve as the disconnect if over 1/8HP 300VA. I'm thinking of the 430.102(B) exceptions.
 

kwired

Electron manager
Location
NE Nebraska
Can you clarify this for me regarding just article 430? It looks like you're saying that 430 doesn't allow remote lockable disconnect to serve as the disconnect if over 1/8HP 300VA. I'm thinking of the 430.102(B) exceptions.
1/8 hp/300 VA is in art 422. I'm sort of assuming you actually have art 440 application, there is no such exceptions that I can think of there.

I mentioned art 422 and 430 because they have some similarities and sometimes people do get confused which one actually applies to them at times.

430.102(B)(1) exception - has informational note that describes a few situtations where one may be able to use it. But like I said, you likely have a 440 application and there is no such exception in 440.
 

NTesla76

Member
Location
IA
What am I not seeing in 422.31? A, B, and C seem to all be saying the same thing. The commentary seems to contradict what A, B, and C are saying. 2017 NEC.
 
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jap

Senior Member
Depending on your location in relationship to the disconnect, you could have the disconnect mounted to the unit itself and it still not be within sight while working on the unit.

I never really agreed with the "within sight" rule.

I simply do not see the benefit of requiring a disconnect to be within sight.

JAP>
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
Depending on your location in relationship to the disconnect, you could have the disconnect mounted to the unit itself and it still not be within sight while working on the unit.

I never really agreed with the "within sight" rule.

I simply do not see the benefit of requiring a disconnect to be within sight.

JAP>
So you can yell at the guy who looks like he's going to switch the disconnect back ON, or at least be warned to step back if he does switch it ON?
 

kwired

Electron manager
Location
NE Nebraska
Depending on your location in relationship to the disconnect, you could have the disconnect mounted to the unit itself and it still not be within sight while working on the unit.

I never really agreed with the "within sight" rule.

I simply do not see the benefit of requiring a disconnect to be within sight.

JAP>
So you can yell at the guy who looks like he's going to switch the disconnect back ON, or at least be warned to step back if he does switch it ON?
Well yes, but at same time I can see having equipment sufficiently large that you can not see the disconnecting means from all portions of the equipment. Here we are talking about HVAC units where most the dangers are having voltage present and some danger of moving propeller on any cooling fans, other machinery can have lots of mechanical caused injury risks if a motor would start and you could easily be well out of sight of the driving motor. NEC only says within sight of the motor or at least within sight of the appliance if it is a listed unit of some sort. At some point you still need to use common sense at very least or apply other safety policies and use LOTO procedure of some sort, which can also include locking off other energy sources involved like air, gas, hydraulics...
 

mwm1752

Senior Member
Location
Aspen, Colo
Qualified service people have some protocol for safety - lock off is simple -- IF you are not qualified then thinning out the heard is the next option available.
 
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