Electrician Talk banner
1 - 20 of 34 Posts

·
Registered
Joined
·
6,459 Posts
Discussion Starter · #1 ·
What are the typical size and number of circuits that are used for walk-in coolers, meat freezers, beer fridges and any other refrigeration set ups. This is something I has no experience with, and id like to know more about.
 

·
Registered
Joined
·
6,459 Posts
Discussion Starter · #4 ·
Compressor circuit, defrost circuit, lighting circuit, door warmer circuit. Off the top of my head
Control, anti sweat, defrost, compressor racks, display lights, evaporator fans, condenser unit fans.
Are these all 120v 20 amp circuits? Any 208v circuits needed?
 

·
Senile Member
I make all the electrons line up for their Flu shots
Joined
·
35,342 Posts
I run 208 single or three phase typical circuit for compressor, ditto for combination of evap motor and defrost on another circuit, and a 120 for door lights, warming tape, door heater, etc.
 

·
Registered
Joined
·
6,459 Posts
Discussion Starter · #11 ·
Working with a refrigeration contractor who specializes in change-outs and upgrades, what would be the typical work needed with this type of work?
 

·
Registered
Joined
·
8,054 Posts
Coolers are pretty straightforward. Compressors will probably be mounted outside and you'll need to feed the fans on the inside. A heating circuit will be required for defrosting lines, this will require control circuits usually tied between the compressor and the heater on the inside.

One thing, watch your wiring methods. I've wired coolers under several different inspectors, each one had his own idea of what the wiring method should be. I'd just do it the way they prefer
 

·
Registered
Joined
·
11,762 Posts
Compressor and defrost circuits will be 208, possibly evaporator too. Sorry it's been a while

If you have 480 go for that. Most of the refrigeration racks Ive seen in large scale supermarkets were 480. Evaporator fans were 120 or 208 defrost, surpentin, mullen, case, ect were all 208. Lighting was mostly 277 strip cases while the stand alones had 120.

BBQ will know way more than me though.
 

·
Banned
Joined
·
16,967 Posts
Working with a refrigeration contractor who specializes in change-outs and upgrades, what would be the typical work needed with this type of work?
Get used to working with lots of MC cable, seal-tight and EMT. A knowledge of control systems and motor starters helps for large systems with control panels and parallel compressor racks. Being able to read and interpret diagrams and schematics is also vital.
 

·
Registered
Joined
·
2,923 Posts
My experience tells me not to quote it unless you can get a schematic and know where the compressors are going.

The last one I did I brought power up to the compressor on the roof. From there, the compressors came prewired in sealtite and I just had to extend that to the fans.
 

·
Senile Member
I make all the electrons line up for their Flu shots
Joined
·
35,342 Posts
X, N, 3, 4. That and expanding foam and thats 90 % of it....... Oh, and don't drill any holes in the bottom of the evap drain pan. :no:
 

·
Registered
Joined
·
11,762 Posts
Coolers are pretty straightforward. Compressors will probably be mounted outside and you'll need to feed the fans on the inside. A heating circuit will be required for defrosting lines, this will require control circuits usually tied between the compressor and the heater on the inside.

One thing, watch your wiring methods. I've wired coolers under several different inspectors, each one had his own idea of what the wiring method should be. I'd just do it the way they prefer
Keep in mind many newer installs no longer have defrost heaters on the evaporators if Hot or "Cool" gas defrost is used which is becoming the norm now, so that will free circuits up quick. Compressors tend to be in a designated compressor room (side by side mounting is not unheard of) while roof mounted condenser units are used for heat exchange.

Case, display and coolers will all have tons of control wiring for everything from defrost termination to temperature sensors for remote monitoring.

Be prepared to learn a lot of what Carrier, Hill Phoenix and the like has to offer too.
 

·
Banned
Joined
·
16,967 Posts
If you have 480 go for that. Most of the refrigeration racks Ive seen in large scale supermarkets were 480. Evaporator fans were 120 or 208 defrost, surpentin, mullen, case, ect were all 208. Lighting was mostly 277 strip cases while the stand alones had 120.

BBQ will know way more than me though.
Here's my best attempt at describing a large parallel rack system that you'd find in a supermarket:

Compressors are plumbed into a large header and individually controlled by pressure transducers on the header. This system will usually be factory assembled and have a factory control panel, but they used to be built with individual pieces on site. Voltage is 480.

Electric defrost- controlled from a dedicated panel, 208 volts, 3 phase. Hot gas defrost controlled via solenoids and energy management.

Solenoids for each loop - controlled by refrigeration control panel (same as the compressor control panel) 208 V

Fans are directly wired to circuit breakers and run constantly. 120 V

Lighting controlled by contactor panel, by energy management. 120 V

Temperature monitoring is done by an energy management system. This also interfaces with the control rack to turn the solenoids on and off as needed.
 

·
Registered
Joined
·
8,054 Posts
MTW said:
Here's my best attempt at describing a large parallel rack system that you'd find in a supermarket: Compressors are plumbed into a large header and individually controlled by pressure transducers on the header. This system will usually be factory assembled and have a factory control panel, but they used to be built with individual pieces on site. Voltage is 480. Electric defrost- controlled from a dedicated panel, 208 volts, 3 phase. Hot gas defrost controlled via solenoids and energy management. Solenoids for each loop - controlled by refrigeration control panel (same as the compressor control panel) 208 V Fans are directly wired to circuit breakers and run constantly. 120 V Lighting controlled by contactor panel, by energy management. 120 V Temperature monitoring is done by an energy management system. This also interfaces with the control rack to turn the solenoids on and off as needed.
Nerd!
 
1 - 20 of 34 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top