Hacking the fridge

The fridge broke, wish we can just buy a new one, but it's too big to replace.

As far as i can tell, the evaporator is icing up and we need to defrost it everyday. Right now, we are just flipping the circuit breaker daily. So, i need to wire up a relay driven by the rPi.

The reading on the compressor label:

AJ100QT-183-J7 2080239V LRA 41.8 1PH

Does it mean 41.8 A of current?

Reply to
edward.ming.lee
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il.com:

lace.

t everyday. Right now, we are just flipping the circuit breaker daily. So , i need to wire up a relay driven by the rPi.

Locked Rotor Amps

Reply to
Lasse Langwadt Christensen

mail.com:

eplace.

it everyday. Right now, we are just flipping the circuit breaker daily. So, i need to wire up a relay driven by the rPi.

So, i need a 50A relay.

Reply to
edward.ming.lee

It's not broke, it's LOW on refrigerant, probably Freon if it's not relatively new.

You should be posting on the basic/amateur/green groups >:-}

LRA = Locked Rotor Amps ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Reply to
Jim Thompson

Just recharged for $450 (repair bill). Compressor is strong and well. pipes are icing up.

Reply to
edward.ming.lee

The evaporator icing up may be caused by low freon. Defrosting it every day may fix it for a few months.

Reply to
krw

Technician already recharged it twice for $450 billing.

Reply to
edward.ming.lee

lace.

t everyday. Right now, we are just flipping the circuit breaker daily. So , i need to wire up a relay driven by the rPi.

I assume this is automatic defrost so there are a handful of components to eyeball and test. First check to see that evaporator fan is blowing when co mpressor comes on. Refrigerator won't work worth a damn if blower is broken . Turn the thermostat to off. Remove panel at rear of freezer compartment to get at evaporator. Look for heater element, usually at bottom of coil, u nplug connectors and do continuity check, ohmage should be consistent with

100-300 watts, if that checks okay, look for Klixon type bimetal clipped to coil in series with heater wiring, check that it is closed, if that checks okay, look for defrost timer ( it will exterior to the refrigerated compar tment most of the time but has been known to be connected into icemaker ope ration), there will be a keyed knob on front, spin it until it clicks into defrost detent, turn thermostat on and eyeball the heater coming on, gettin g warm, usually for only 5-10 minutes, then klixon cuts the circuit out, wa tch the water drain into collection pan at bottom of coil, see that it dra ins, pull veg tray at bottom of fresh food compartment and locate drain hol e, check that water is draining, clear any clogged drains with long stiff w ire if necessary (usually clogged with spilled food). Sometimes there is sm all heater under collection pan in freezer or around its drain tube, if you have a bunch of ice in pan it means heater is open, find this heater and check it, no drainage means no defrost and water just gets recirculated bac k to coil quickly, wait out defrost timer for 20-30 minutes to see that it cycles compressor back on, and defrost fan starts blowing. One or more of t hose stages of defrost operation will fail and indicate the failed part.
Reply to
bloggs.fredbloggs.fred

snipped-for-privacy@gmail.com wrote on 10/1/2017 3:46 PM:

You mean "too big to fail"?

Couldn't you have it repaired?

Is it a walk in type? You could buy an in line watt meter and measure the current/power.

--
Rick C 

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Reply to
rickman

On Sunday, October 1, 2017 at 1:23:54 PM UTC-7, snipped-for-privacy@gmail.com wr ote:

e:

eplace.

it everyday. Right now, we are just flipping the circuit breaker daily. So, i need to wire up a relay driven by the rPi.

o eyeball and test. First check to see that evaporator fan is blowing when compressor comes on. Refrigerator won't work worth a damn if blower is brok en. Turn the thermostat to off. Remove panel at rear of freezer compartmen t to get at evaporator. Look for heater element, usually at bottom of coil, unplug connectors and do continuity check, ohmage should be consistent wit h 100-300 watts, if that checks okay, look for Klixon type bimetal clipped to coil in series with heater wiring, check that it is closed, if that chec ks okay, look for defrost timer ( it will exterior to the refrigerated comp artment most of the time but has been known to be connected into icemaker o peration), there will be a keyed knob on front, spin it until it clicks int o defrost detent, turn thermostat on and eyeball the heater coming on, gett ing warm, usually for only 5-10 minutes, then klixon cuts the circuit out, watch the water drain into collection pan at bottom of coil, see that it d rains, pull veg tray at bottom of fresh food compartment and locate drain h ole, check that water is draining, clear any clogged drains with long stiff wire if necessary (usually clogged with spilled food). Sometimes there is small heater under collection pan in freezer or around its drain tube, if y ou have a bunch of ice in pan it means heater is open, find this heater an d check it, no drainage means no defrost and water just gets recirculated b ack to coil quickly, wait out defrost timer for 20-30 minutes to see that i t cycles compressor back on, and defrost fan starts blowing. One or more of those stages of defrost operation will fail and indicate the failed part.

OK, thanks for the tips. The evaporator fan is on all the time, on a separ ate circuit breaker, with or without compressor running. Water is dripping out of the evaporator, not blocked inside. I am wondering if there is a l eak in the refrigerant pipe.

Reply to
edward.ming.lee

I mean too big to dump and buy a new one.

Until we can find the problem, stopping the compressor for an hour everyday solve it for now.

Yes, a big walk-in frig.

Reply to
edward.ming.lee

On Sunday, October 1, 2017 at 4:38:02 PM UTC-4, snipped-for-privacy@gmail.com wrote:

wrote:

ote:

replace.

st it everyday. Right now, we are just flipping the circuit breaker daily. So, i need to wire up a relay driven by the rPi.

to eyeball and test. First check to see that evaporator fan is blowing whe n compressor comes on. Refrigerator won't work worth a damn if blower is br oken. Turn the thermostat to off. Remove panel at rear of freezer compartm ent to get at evaporator. Look for heater element, usually at bottom of coi l, unplug connectors and do continuity check, ohmage should be consistent w ith 100-300 watts, if that checks okay, look for Klixon type bimetal clippe d to coil in series with heater wiring, check that it is closed, if that ch ecks okay, look for defrost timer ( it will exterior to the refrigerated co mpartment most of the time but has been known to be connected into icemaker operation), there will be a keyed knob on front, spin it until it clicks i nto defrost detent, turn thermostat on and eyeball the heater coming on, ge tting warm, usually for only 5-10 minutes, then klixon cuts the circuit out , watch the water drain into collection pan at bottom of coil, see that it drains, pull veg tray at bottom of fresh food compartment and locate drain hole, check that water is draining, clear any clogged drains with long sti ff wire if necessary (usually clogged with spilled food). Sometimes there i s small heater under collection pan in freezer or around its drain tube, if you have a bunch of ice in pan it means heater is open, find this heater and check it, no drainage means no defrost and water just gets recirculated back to coil quickly, wait out defrost timer for 20-30 minutes to see that it cycles compressor back on, and defrost fan starts blowing. One or more of those stages of defrost operation will fail and indicate the failed part .

arate circuit breaker, with or without compressor running. Water is drippi ng out of the evaporator, not blocked inside. I am wondering if there is a leak in the refrigerant pipe.

Seems unusual for the evaporator fan to run continuously. You should not ha ve dripping anywhere except the external drain hose. Track down where that water is coming from. If the closed system was leaking you wouldn't have an ything freezing up. If it's the low side pipe between the evaporator outlet and the compressor that is developing condensation: check that pipe insula tion has not been removed or is still intact, the condenser fan is still bl owing as its airstream is usually directed over return pipe to superheat th e refrigerant vapor before it hits the compressor, all baffles in compresso r/condenser compartment are in place and not damaged so airflow loop is int act. There is an exponential dependence of proper operation on airflow ther e.

Reply to
bloggs.fredbloggs.fred

On Sunday, October 1, 2017 at 4:38:02 PM UTC-4, snipped-for-privacy@gmail.com wrote:

wrote:

ote:

replace.

st it everyday. Right now, we are just flipping the circuit breaker daily. So, i need to wire up a relay driven by the rPi.

to eyeball and test. First check to see that evaporator fan is blowing whe n compressor comes on. Refrigerator won't work worth a damn if blower is br oken. Turn the thermostat to off. Remove panel at rear of freezer compartm ent to get at evaporator. Look for heater element, usually at bottom of coi l, unplug connectors and do continuity check, ohmage should be consistent w ith 100-300 watts, if that checks okay, look for Klixon type bimetal clippe d to coil in series with heater wiring, check that it is closed, if that ch ecks okay, look for defrost timer ( it will exterior to the refrigerated co mpartment most of the time but has been known to be connected into icemaker operation), there will be a keyed knob on front, spin it until it clicks i nto defrost detent, turn thermostat on and eyeball the heater coming on, ge tting warm, usually for only 5-10 minutes, then klixon cuts the circuit out , watch the water drain into collection pan at bottom of coil, see that it drains, pull veg tray at bottom of fresh food compartment and locate drain hole, check that water is draining, clear any clogged drains with long sti ff wire if necessary (usually clogged with spilled food). Sometimes there i s small heater under collection pan in freezer or around its drain tube, if you have a bunch of ice in pan it means heater is open, find this heater and check it, no drainage means no defrost and water just gets recirculated back to coil quickly, wait out defrost timer for 20-30 minutes to see that it cycles compressor back on, and defrost fan starts blowing. One or more of those stages of defrost operation will fail and indicate the failed part .

arate circuit breaker, with or without compressor running. Water is drippi ng out of the evaporator, not blocked inside. I am wondering if there is a leak in the refrigerant pipe.

Is this a residential unit or a commercial walk-in type deal? They have com pletely different defrost techniques.

Reply to
bloggs.fredbloggs.fred

On Sunday, October 1, 2017 at 1:58:10 PM UTC-7, snipped-for-privacy@gmail.com wr ote:

e:

m wrote:

wrote:

to replace.

rost it everyday. Right now, we are just flipping the circuit breaker dail y. So, i need to wire up a relay driven by the rPi.

ts to eyeball and test. First check to see that evaporator fan is blowing w hen compressor comes on. Refrigerator won't work worth a damn if blower is broken. Turn the thermostat to off. Remove panel at rear of freezer compar tment to get at evaporator. Look for heater element, usually at bottom of c oil, unplug connectors and do continuity check, ohmage should be consistent with 100-300 watts, if that checks okay, look for Klixon type bimetal clip ped to coil in series with heater wiring, check that it is closed, if that checks okay, look for defrost timer ( it will exterior to the refrigerated compartment most of the time but has been known to be connected into icemak er operation), there will be a keyed knob on front, spin it until it clicks into defrost detent, turn thermostat on and eyeball the heater coming on, getting warm, usually for only 5-10 minutes, then klixon cuts the circuit o ut, watch the water drain into collection pan at bottom of coil, see that it drains, pull veg tray at bottom of fresh food compartment and locate dra in hole, check that water is draining, clear any clogged drains with long s tiff wire if necessary (usually clogged with spilled food). Sometimes there is small heater under collection pan in freezer or around its drain tube, if you have a bunch of ice in pan it means heater is open, find this heate r and check it, no drainage means no defrost and water just gets recirculat ed back to coil quickly, wait out defrost timer for 20-30 minutes to see th at it cycles compressor back on, and defrost fan starts blowing. One or mor e of those stages of defrost operation will fail and indicate the failed pa rt.

eparate circuit breaker, with or without compressor running. Water is drip ping out of the evaporator, not blocked inside. I am wondering if there is a leak in the refrigerant pipe.

ompletely different defrost techniques.

Commercial walk-in. It's just a fridge, not a freezer. Normally, it shoul d not be freezing.

Reply to
edward.ming.lee

That is the locked rotor current. That is the starting surge when the compressor starts.

You most likely have a bad defrost heater (located in the freezer area) or a bad defrost timer (bottom of the unit). Google the model number and see if you can find a manual and schematic.

Reply to
tom

That was a joke.

Doesn't the repair guy usually find the problem?

How long do you plan to manually defrost rather than having it repaired? What's wrong with using the switch for a couple of days?

--
Rick C 

Viewed the eclipse at Wintercrest Farms, 
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Reply to
rickman

The repair guy charged $450 just to recharge the refrigerant. Wonder how much he would charge to fix the problem.

Reply to
edward.ming.lee

On Sunday, October 1, 2017 at 5:02:11 PM UTC-4, snipped-for-privacy@gmail.com wrote:

wrote:

ote:

com wrote:

m wrote:

g to replace.

efrost it everyday. Right now, we are just flipping the circuit breaker da ily. So, i need to wire up a relay driven by the rPi.

ents to eyeball and test. First check to see that evaporator fan is blowing when compressor comes on. Refrigerator won't work worth a damn if blower i s broken. Turn the thermostat to off. Remove panel at rear of freezer comp artment to get at evaporator. Look for heater element, usually at bottom of coil, unplug connectors and do continuity check, ohmage should be consiste nt with 100-300 watts, if that checks okay, look for Klixon type bimetal cl ipped to coil in series with heater wiring, check that it is closed, if tha t checks okay, look for defrost timer ( it will exterior to the refrigerate d compartment most of the time but has been known to be connected into icem aker operation), there will be a keyed knob on front, spin it until it clic ks into defrost detent, turn thermostat on and eyeball the heater coming on , getting warm, usually for only 5-10 minutes, then klixon cuts the circuit out, watch the water drain into collection pan at bottom of coil, see tha t it drains, pull veg tray at bottom of fresh food compartment and locate d rain hole, check that water is draining, clear any clogged drains with long stiff wire if necessary (usually clogged with spilled food). Sometimes the re is small heater under collection pan in freezer or around its drain tube , if you have a bunch of ice in pan it means heater is open, find this hea ter and check it, no drainage means no defrost and water just gets recircul ated back to coil quickly, wait out defrost timer for 20-30 minutes to see that it cycles compressor back on, and defrost fan starts blowing. One or m ore of those stages of defrost operation will fail and indicate the failed part.

separate circuit breaker, with or without compressor running. Water is dr ipping out of the evaporator, not blocked inside. I am wondering if there is a leak in the refrigerant pipe.

completely different defrost techniques.

uld not be freezing.

Right, a walk-in cooler with remote compressor unit, no wonder they charged $450 for a charge. Did they pull vacuum on it and check that it held befor e they recharged? You should have a big defrost timer box located near the compressor. To defrost they usually just cut out the compressor and allow t he evaporator fan to draw the above freezing air through the coil until it melts. They detect melted coil with a pressure switch in the refrigerant li ne that switches out when the pressure corresponds to a coil temp of someth ing 38-40oF, and then it's followed by a 10-15 minute idle time to allow th e water to drain away, then it switches the cooling cycle back in. Since th ey keep the coil around 32oF in operation, it is possible for a freeze up i f the defrost cycle stops working. You're looking for something that looks like this: in the rectanglualr gray boxes to left

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, there will be a diagram inside the cove r showing you how it is wired in. Or it could be a leak, usually the evapor ator coil, which is usually aluminum, in which case you change out the whol e evaporator coil, not worth trying to patch it with epoxy.

Reply to
bloggs.fredbloggs.fred

On Sunday, October 1, 2017 at 5:02:11 PM UTC-4, snipped-for-privacy@gmail.com wrote:

wrote:

ote:

com wrote:

m wrote:

g to replace.

efrost it everyday. Right now, we are just flipping the circuit breaker da ily. So, i need to wire up a relay driven by the rPi.

ents to eyeball and test. First check to see that evaporator fan is blowing when compressor comes on. Refrigerator won't work worth a damn if blower i s broken. Turn the thermostat to off. Remove panel at rear of freezer comp artment to get at evaporator. Look for heater element, usually at bottom of coil, unplug connectors and do continuity check, ohmage should be consiste nt with 100-300 watts, if that checks okay, look for Klixon type bimetal cl ipped to coil in series with heater wiring, check that it is closed, if tha t checks okay, look for defrost timer ( it will exterior to the refrigerate d compartment most of the time but has been known to be connected into icem aker operation), there will be a keyed knob on front, spin it until it clic ks into defrost detent, turn thermostat on and eyeball the heater coming on , getting warm, usually for only 5-10 minutes, then klixon cuts the circuit out, watch the water drain into collection pan at bottom of coil, see tha t it drains, pull veg tray at bottom of fresh food compartment and locate d rain hole, check that water is draining, clear any clogged drains with long stiff wire if necessary (usually clogged with spilled food). Sometimes the re is small heater under collection pan in freezer or around its drain tube , if you have a bunch of ice in pan it means heater is open, find this hea ter and check it, no drainage means no defrost and water just gets recircul ated back to coil quickly, wait out defrost timer for 20-30 minutes to see that it cycles compressor back on, and defrost fan starts blowing. One or m ore of those stages of defrost operation will fail and indicate the failed part.

separate circuit breaker, with or without compressor running. Water is dr ipping out of the evaporator, not blocked inside. I am wondering if there is a leak in the refrigerant pipe.

completely different defrost techniques.

uld not be freezing.

One last possibility is a fairly large leak in the compartment seal either at the door or some other place where they run wiring/piping into the compa rtment. A defective/damaged door seal, especially in a high humidity area, will really screw you over, as the defrost cycle cannot keep up. Check to s ee the box is airtight.

Reply to
bloggs.fredbloggs.fred

On Sunday, October 1, 2017 at 2:18:34 PM UTC-7, snipped-for-privacy@gmail.com wr ote:

e:

m wrote:

wrote:

l.com wrote:

com wrote:

big to replace.

defrost it everyday. Right now, we are just flipping the circuit breaker daily. So, i need to wire up a relay driven by the rPi.

onents to eyeball and test. First check to see that evaporator fan is blowi ng when compressor comes on. Refrigerator won't work worth a damn if blower is broken. Turn the thermostat to off. Remove panel at rear of freezer co mpartment to get at evaporator. Look for heater element, usually at bottom of coil, unplug connectors and do continuity check, ohmage should be consis tent with 100-300 watts, if that checks okay, look for Klixon type bimetal clipped to coil in series with heater wiring, check that it is closed, if t hat checks okay, look for defrost timer ( it will exterior to the refrigera ted compartment most of the time but has been known to be connected into ic emaker operation), there will be a keyed knob on front, spin it until it cl icks into defrost detent, turn thermostat on and eyeball the heater coming on, getting warm, usually for only 5-10 minutes, then klixon cuts the circu it out, watch the water drain into collection pan at bottom of coil, see t hat it drains, pull veg tray at bottom of fresh food compartment and locate drain hole, check that water is draining, clear any clogged drains with lo ng stiff wire if necessary (usually clogged with spilled food). Sometimes t here is small heater under collection pan in freezer or around its drain tu be, if you have a bunch of ice in pan it means heater is open, find this h eater and check it, no drainage means no defrost and water just gets recirc ulated back to coil quickly, wait out defrost timer for 20-30 minutes to se e that it cycles compressor back on, and defrost fan starts blowing. One or more of those stages of defrost operation will fail and indicate the faile d part.

a separate circuit breaker, with or without compressor running. Water is dripping out of the evaporator, not blocked inside. I am wondering if ther e is a leak in the refrigerant pipe.

ve completely different defrost techniques.

hould not be freezing.

ed $450 for a charge. Did they pull vacuum on it and check that it held bef ore they recharged? You should have a big defrost timer box located near th e compressor. To defrost they usually just cut out the compressor and allow the evaporator fan to draw the above freezing air through the coil until i t melts. They detect melted coil with a pressure switch in the refrigerant line that switches out when the pressure corresponds to a coil temp of some thing 38-40oF, and then it's followed by a 10-15 minute idle time to allow the water to drain away, then it switches the cooling cycle back in. Since they keep the coil around 32oF in operation, it is possible for a freeze up if the defrost cycle stops working. You're looking for something that look s like this: in the rectanglualr gray boxes to left

formatting link
, there will be a diagram inside the co ver showing you how it is wired in. Or it could be a leak, usually the evap orator coil, which is usually aluminum, in which case you change out the wh ole evaporator coil, not worth trying to patch it with epoxy.

That's what i was looking for first, but no external timer. There is a pre ssure sensor next to the compressor, but no timer.

Reply to
edward.ming.lee

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