walk-in freezer door

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EEC

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Are there electric heaters in the door and the door jam frame of walk-in freezer? I noticed so cord installed into the swinging door? There is also a light switch outside the freezer at the door entrance.
 
Yes, walk in freezers have door heaters. The units schematics will show the connection.

Roger
 
In my experience it's just the door jamb. As far as what the resistance is, I don't know, but it is usually a very small load, is there no paper work with this freezer?

Roger
 
EEC said:
Are heaters in jam and door?
Click to expand...

On a typical walk in freezer there will be heaters at the door seals on the doors and heaters in the door jambs where the seals meet the jambs.

If they are glass doors they will also have heat in the metal trim around the glass to control condensation and keep the glass clear.


what's the ohm reading to expect?
Click to expand...

Could be anything, that would be model specific.
 
-marty said:
Many door heaters I see need to be disconnected if the freezer is off.
Click to expand...
You bet they do. You'll get a tell-tale brown line in the gasket the whole way around if you don't.

For testing, I've never found a failed one that wasn't failed "open". If you get some kind of low ohm reading at all, chances are you have a good jamb heater. Just be sure to read the tag on the cold leads of the replacement jamb heater and see that you have either a 120 or 240 jamb heater, so you connect it to the right voltage. They're available both ways. Replacement walk-in box jamb heaters are generally 18 feet and 36 feet in heating length and are generally 3 watts per foot of heating length. (if there's any extra length, it's most often zig-zagged under the threshold plate).

18 foot = 54 watts = 266 ohms at 120 or 1066 ohms at 240
36 foot = 108 watts = 133 ohms at 120 or 533 ohms at 240

Just a bit of rule of thumb stuff.
 
Some of the more recent walk-in boxes have a thermostat for the jamb heater, which is normally mounted near the defrost control. It has a little thermistor buried in the jamb, normally about halfway up on the latch side of the door. If you have a good jamb heater but the jamb is frozen, suspect a bad thermistor. These can be ohmed out as well. Normally it's a Ranco thermistor.
 
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