Cold storage room evaporating coolers

[Hasny]

I am in the process of *designing a cold storage room, where should I provide the disconnect switch for the evaporating coolers (2 nos) and lighting fixtures. Should it be inside the cold storage room or outside.*

[beenthere]

Moved to Refrigeration and ice making forum.

[steve36558]

It can be inside or outside box. Evap coils will need a means of disconnect in any case for code. So a tech can work on unit while the power is turned off.

[Hasny]

My concern was, that DS put inside should not get effected with the moist environment inside. So no issues I suppose, one should go for weather proof ones I guess. Thanks anyway.

[2sac]

Weatherproof are fine. Seperate disconnects for each coil and a seperate one for lighting.

[Hasny]

Thanks 2sak

[trippintl0]

Actually, we have had a restaurant with this same setup and end up having an issue. Here's the scenario: Walk-in-cooler, two evaporators, each with a disconnect, but only one evaporator has the thermostat. So anytime they do inventory, they want to turn off the fans, but only on that side of the cooler. So when they turn off the slave evaporator, the refrigerant still flows through it since the solenoid is powered through the master evaporator. And naturally, they forget to turn the coil back on, until half a day later, and by then the thing is frozen solid. (Yes this has happened more than once.)

One solution would be to use a dual pole switch on the slave evaporator, and run the thermostat wire all the way from the master to the slave evaporator, (in series) through the 2nd pole of the switch, then back to the master, so that no matter which switch gets turned off, it will kill the solenoid. I'm sure there is probably a prettier solution too but I can't think of what it is...

(...well of course a single disconnect would solve this problem too, not sure if that is some electrical code or whatnot.)

[beenthere]

Actually, we have had a restaurant with this same setup and end up having an issue. Here's the scenario: Walk-in-cooler, two evaporators, each with a disconnect, but only one evaporator has the thermostat. So anytime they do inventory, they want to turn off the fans, but only on that side of the cooler. So when they turn off the slave evaporator, the refrigerant still flows through it since the solenoid is powered through the master evaporator. And naturally, they forget to turn the coil back on, until half a day later, and by then the thing is frozen solid. (Yes this has happened more than once.)

One solution would be to use a dual pole switch on the slave evaporator, and run the thermostat wire all the way from the master to the slave evaporator, (in series) through the 2nd pole of the switch, then back to the master, so that no matter which switch gets turned off, it will kill the solenoid. I'm sure there is probably a prettier solution too but I can't think of what it is...

(...well of course a single disconnect would solve this problem too, not sure if that is some electrical code or whatnot.)

Or just add a contactor for the solenoid that the coil is powered from the same circuit as the fans. Run the stat wires through the contacts of the contactor. Then when they kill power to the fans, the solenoid closes.

[ryan1088]

Actually, we have had a restaurant with this same setup and end up having an issue. Here's the scenario: Walk-in-cooler, two evaporators, each with a disconnect, but only one evaporator has the thermostat. So anytime they do inventory, they want to turn off the fans, but only on that side of the cooler. So when they turn off the slave evaporator, the refrigerant still flows through it since the solenoid is powered through the master evaporator. And naturally, they forget to turn the coil back on, until half a day later, and by then the thing is frozen solid. (Yes this has happened more than once.)

One solution would be to use a dual pole switch on the slave evaporator, and run the thermostat wire all the way from the master to the slave evaporator, (in series) through the 2nd pole of the switch, then back to the master, so that no matter which switch gets turned off, it will kill the solenoid. I'm sure there is probably a prettier solution too but I can't think of what it is...

(...well of course a single disconnect would solve this problem too, not sure if that is some electrical code or whatnot.)

I think the answer is they need to man up and put a coat, hat, and gloves on like the rest of us do!

[trippintl0]

That's exactly what they do now, since I bypassed both of the switches!! Either that or they turn off they single circuit breaker that shuts off both evaporators