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I've completed wiring a commercial Walk-in freezer for a restaurant and have a correction for no disconnecting means for the coil inside the unit. The compressor unit on the roof has a standard fused disconnect, and the only power being fed down to the coil is the standard 4 conductors (N,X,3, and 4). The inspector wants there to be a disconnecting means at the walk-in freezer itself. The freezer is within sight of the panel, but obviously you can't see the panel from the coil itself. I'm thinking that a lock-off on the breaker should solve the problem, but 440.14 is vague as to what they mean by "in sight of the air-conditioning or refrigeration equipment". Do they mean the walk-in freezer, or the coil inside? I've never seen a second disconnect for the freezer coil only, and if I do have to install one, the only way I can see to feasibly do this is to run the feeders to a 2-pole switch inside the freezer, then up to the disconnect on the roof.
Any ideas?
thanks
 

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The disconnecting means inside the box is only for the fans, door heat strips, defroster and other local equipment. Asking for a disconnect for the rooftop unit inside the freezer is just stupid. UNLESS of course the roof unit feeds the box, which I have never seen. Electrically there is typically no connection from the roof (remote) unit to the box.

I usually just put a switch inside the box near the fan unit.
 

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I believe he's only interested is disconnecting the power to the coil....but that consists of both the switched leg to the fans, and the switched leg to the heaters. Short of installing (2) 2-pole switches (1 for each switched load), the most convenient (though not practical) is to re-route the power from the panel to a 2-pole switch inside the freezer on the coil, then up to the roof.
I've looked all through the code book and can't find a good argument against doing this anywhere...but it just doen't make sense.
 

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If I install a disconnect at the evaporator [unit cooler] it is normally by choice. I usually just mount a spec grade toggle switch in a WP Bell box and simply break the line before it even goes to the defrost timer. This is usually the easiest and most cost effective way, at least for me, and it should satisfy your inspector.

No matter how you decide to do it though, it’s important to make sure you also break power to the liquid line solenoid [LLS]. This closes the liquid valve so the compressor can shut down normally on the low pressure cut-out. Otherwise, if an employee shuts of the evaporator fans during freezer restocking… and it does happen…, the condenser compressor can trip out on the high-pressure safety, which is often a manual reset. When they have finish restocking and turn the evaporator disconnect switch back on, the fans start running and they just assume all is well. If there is no freezer alarm to warn them, they don’t find out until the next morning that the compressor has been down all night and now they have a big problem.
I usually put the door heater, condensate drain heat tape [if 120V], pressure relief baffle heater, etc., on with the walk-in lighting circuit, which I always connect to GFCI circuit breaker anyway.
 

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I should have also mentioned that 2008 NEC 440-14 requires the disconnecting means to be located "within sight FROM and readily accessible FROM the air conditioning and refrigeration equipment".
So, the circuit breaker lock wouldn't appear to cut it.
There are a couple of exceptions, but they wouldn't apply to your installation.
 

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No matter how you decide to do it though, it’s important to make sure you also break power to the liquid line solenoid [LLS]. This closes the liquid valve so the compressor can shut down normally on the low pressure cut-out. Otherwise, if an employee shuts of the evaporator fans during freezer restocking… and it does happen…, the condenser compressor can trip out on the high-pressure safety, which is often a manual reset. When they have finish restocking and turn the evaporator disconnect switch back on, the fans start running and they just assume all is well. If there is no freezer alarm to warn them, they don’t find out until the next morning that the compressor has been down all night and now they have a big problem.
I usually put the door heater, condensate drain heat tape [if 120V], pressure relief baffle heater, etc., on with the walk-in lighting circuit, which I always connect to GFCI circuit breaker anyway.
Wrong, if you take out the fans without the solenoid you won't effect the high pressure in any means, freon will still be pumped to the evaporator coil, with no air movement to boil off. This will cause a low pressure situation and freeze up the coil and possibly send liquid freon back to the compressor and kill it. Having the condenser running without evap. fans is just really bad.

We have done many of these jobs and the circuit breaker has always done fine as a means of disconnect for the evap unit. We have never added any type of disconnect on the inside of a box. As well as the only disconnect means for the door and drain line heaters and box lights being the breaker also.
 

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Wrong, if you take out the fans without the solenoid you won't effect the high pressure in any means, freon will still be pumped to the evaporator coil, with no air movement to boil off. This will cause a low pressure situation and freeze up the coil and possibly send liquid freon back to the compressor and kill it. Having the condenser running without evap. fans is just really bad.

We have done many of these jobs and the circuit breaker has always done fine as a means of disconnect for the evap unit. We have never added any type of disconnect on the inside of a box. As well as the only disconnect means for the door and drain line heaters and box lights being the breaker also.

Well… this is exactly what happens when I stay up too late. I can’t even keep my condenser and evaporator circuits straight, after 12 years of AC/R.
I may now have to relinquish my pro membership on HVAC Talk.:001_huh:
 

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Well… this is exactly what happens when I stay up too late. I can’t even keep my condenser and evaporator circuits straight, after 12 years of AC/R.
I may now have to relinquish my pro membership on HVAC Talk.:001_huh:
Na! Just go ask a diy question and they will take care of it for you!:laughing:
 

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I know this thread is old but in a walk-in freezer there usually is an interconnection between the evap and condenser because of defrost. Usually in a cooler there's no defrost so it's controlled by LLS. Given that, I believe the code is having multiple motors driving one machine and the disconnect needs to be located at the controller(s) 430.102?
 
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