true freezer works....sometimes

[2sac]

We have had numerous issues with the relays on the grasslins welding shut or stuck open ONLY on True freezers. From what I understand, it happens during the inrush of current on startup. The older True design had a Paragon timer. This is from memory, so forgive me if I'm wrong. When True first changed over to Grasslin, they were wired the same way. After having problems, I believe the factory installed a relay in the electrical compartment. The grasslin timer energizes a relay, and not the compressor directly. If you have a unit without a relay, I'd recommend the Paragon

[johnnyb]

If it gets down to _20f .. you probably don't have a refrigeration problem , but rather a control probelem. Thermostat sticking, defrtost timer sticking, defrost termination sticking,loose wire, burnig (going bad ) overload on compressor, burning (going bad ) contact on timer. Afew things to check. You may have to baby sit it to catch it. I also do not like the Graslin. The Paragon ued to be "bulletproof" but I think that all of thagt stuff is foreign made now and the foreigners do not have "high quality " in their vocabulary.

[Phase Loss]

We have had numerous issues with the relays on the grasslins welding shut or stuck open ONLY on True freezers. From what I understand, it happens during the inrush of current on startup. The older True design had a Paragon timer. This is from memory, so forgive me if I'm wrong. When True first changed over to Grasslin, they were wired the same way. After having problems, I believe the factory installed a relay in the electrical compartment. The grasslin timer energizes a relay, and not the compressor directly. If you have a unit without a relay, I'd recommend the Paragon

Now I got ya, makes scene.

I do the same to MR4 controllers. (install external relays)

Good ole mechanical time clocks had nice contacts...these electronic time clocks have crappy relays.

[Snapperhead]

Im going with defrost termination switch , or t stat

[trippintl0]

Make sure the self closing door hinges are working. Because something I've often seen is the customer gets in a hurry and the doors don't get shut all the way, this causes the evaporator fans to turn off, and they don't really notice until the box is already at 35*f, although this still doesn't really explain 80*F box temp.

I agree like everybody else says, probably defrost termination switch is not terminating (or it is, and the timer solenoid or release relay has failed) causing it to stay in defrost for much longer than necessary until box gets so warm.

[socotech]

Just a follow up. I did go and babysit the unit for a few hours and definatly air recirculation problem. Air into condenser getting up to 106 degrees after about two hours of operation and 74 degree ambient. Put a box fan near condenser and it works fine all day. I wonder whats going to happen when its 100+ this summer.

[grandmastad]

Is your compressor hot upon arrival? What happens when your unit goes into defrost?

[sgagne199]

Ya 106 degrees that could have somethingto to do with the compressor tripping on thermal haha

[2sac]

I have mounted 115v coaxial fans on units to redirect discharge air, and have also wired condenser fans to run 24/7 to help cool the pump during the off cycle.

[socotech]

Thanks for everybodys input.

[dave sulz]

I see defrost termination problems usually snap in refrigeration before ice melts causing more ice. Chech pot relay maybe sometimes its not energizing start winding causing off on overload.

[kamersoutdoor]

Im going with defrost termination switch , or t stat

Been changing enough t-stats on True's to ditto that.
Last one I caught as I was packing up!

[trippintl0]

We have had numerous issues with the relays on the grasslins welding shut or stuck open ONLY on True freezers. From what I understand, it happens during the inrush of current on startup. The older True design had a Paragon timer. This is from memory, so forgive me if I'm wrong. When True first changed over to Grasslin, they were wired the same way. After having problems, I believe the factory installed a relay in the electrical compartment. The grasslin timer energizes a relay, and not the compressor directly. If you have a unit without a relay, I'd recommend the Paragon

Just wanted to say "Thanks!" for posting this! I saw it happen today. I knew exactly what it was because of your post.

Here's how True freezers are wired when you retrofit a Grasslin clock where it used to have an 8141 Paragon: the thermostat / condensing unit is powered through the "F" Fan relay, which is a much smaller relay than the "4" relay (even though it says its a 30amp relay). The evap fans power comes from the door switch circuit, down to the clock, then through the "4" relay, which is the 40 amp relay. I watched the thing roll into defrost, heaters came on, but condensing unit ("F" relay) failed to open. So compressor was running through the entire defrost.

Our solution was to install a cube relay so that the thermostat and defrost clock only energize the relay (just like how True does to address same issue), and after that it didn't hang up any more. Hopefully the relay isn't damaged, we just installed that Grasslin timer a couple of months ago...! We will find out.

Makes me wonder whatever happened to the other freezers we've put Grasslin timers on without an external relay...