So you bought a cheap fridge or freezer at WalMart, did ya? Or maybe your old fridge or freezer conked out. The first thing that comes to mind is “THE COMPRESSOR IS OUT”! A scary thought indeed. And you think that because you don’t hear the compressor noise and nothing is cooling anymore.
Compressors are pretty robust devices. They do fail, they sure do, but many times one of the components that connect to the compressor fail causing the compressor not to start. There are three components hooked up to a common refrigerator or freezer compressor.
- Motor Starting Relay
- Starting Capacitor (and possibly a run capacitor)
- Overload Protector
Here is what a compressor hookup looks like typically. There are three male pins that stick out on one end of the compressor:
Some connectors will be inverted so you really need to verify which pin is the correct one.
Many compressors will show the proper hook up on the data label itself.
Here’s an example, yeah you can’t make out what pin is what from my pic but it’s on there:
So the components hook up sorta like this.
- Motor start relay plugs in across the start and run pins. Relay hooks to start capacitor and neutral from thermostat 120v.
Motor Start Relay (typical) (click to enlarge photos)
The motor start relay pin holes just plug in over the start and run pins. Easy peasy.
MOTOR START RELAY
- The motor overload protection device plugs into the pin (COMMON). The Line (120v) wire from the thermostat plugs into the motor overload protection device.
Now let’s talk about fixing this IF it doesn’t start or the freezer isn’t cooling. If the compressor is running but not cooling you probably need a technician, and refrigerant.
If the compressor won’t start and you know which one of the components has failed and it is a reliable, brand name component which lasted for 20 years just order the new part. For example if the motor starting relay failed, just get a new one.
If you have a cheap fridge or freezer which has failed prematurely then I would recommend replacing all three items with a Supco 3 n 1 Hard Start Kit
Okay so what is a “Hard Start Kit”? Sometimes old compressors just need a bigger jolt to get them going but they still will run. This can be due to age, corrosion, weakness of the motor, etc. Theoretically if you put a hard start kit on a compressor that doesn’t need it you can shorten the life of it. In the real world maybe that means the compressor will fail at 19 years old instead of 20.
However if you have a cheap freezer like I did which is notorious for blowing the motor start relay every 1-2 years and if you don’t want to deal with changing a start relay every year or two you might want to go to a hard start kit. They are super easy to hook up
- Red wire = Run
- Whte wire = start
- Black wire= Common
- Remaining 2 wires with no connector = 120 volt
Remember, if you didn’t NEED a hard start kit to kick over your compressor, you can theoretically shorten the service life of the compressor.
I find this an acceptable risk on a new, inexpensive device with early failure rates of components.
And also remember if you do NEED a hard start kit….your compressor is almost done for anyway.
Anyway if you own a refrigerator or freezer (you probably do) you should probably have a hard start kit laying around ANYWAY for EMERGENCIES. Having your freezer die in July with $400 worth of meat in it is considered an emergency in my estimation.
In conclusion……..calling a repairman is expensive. Motor start relays, and motor overload devices and capacitors are inexpensive and literally just plug in over pins. Supco 3 n 1 Hard Start kits have all three of those components in one convenient can and are super easy to hook up. Just remember to remove the old components which may be bad first. I’ve actually seen that before.
Actually if your fridge doesn’t have a hard start kit already installed installing one now can actually extend the life of the compressor due to reduced starting amps. But its all for naught if you don’t double check the run cap microfared rating while your at it.
This also applies to your home AC but requires a different type of hard start kit that uses a potential relay and is sized for the compressor.
I am working with two refrigerators in my home (one acquired because it was given to me after it quick working and I hope to fix it). However, both are experiencing compressor start up on a call for cooling. I replaced the OEM capacitor and thermal overload relay with a Supco 810. Checked compressor pin resistance to verify start and run winding loops. Hooked it up. cleaned condenser coil and evaporator coil. Check defrost cycle for correct operation. Checked evaporator fan for operation. The units will begin to work well cooling freezer to 20-Deg. F and refrig. to 40-Deg F. However, after several days, the compressor would not restart. This has occurred on both “hard start” installations. If you unplug power to let compressor refrigerant pressure equalize, the compressor will restart. I am considering replacing evaporator fan and refrig. thermostat but this does not address why compressor will not restart under a load. Can you help me with diagnosis?
please send email reply
In your case you need an additional timer delay to let the pressure equalise after turning off before starting up again. It’s like trying to start your car in gear. It is working under pressure in the system right from the first turn.
Most Temperature controllers have this delay function, or at least the modern ones do.
In my case, I installed a 3 N’ 1 on a 3year old chest freezer, the compressor starts alright but then after a few seconds, it changes to a hum and it gets super hot over several minutes and eventually just stops. Letting it cool for a few hours and trying again does the same thing. Starts, hums, overheats. Thoughts?
Sounds like the compressor may be failing or sticking.
Thanks John, it’s what I thought too but I recently found out that there is such a device as a 4 N’ 1 for higher efficiency compressors that use a run capacitor and I’m wondering if this newer freezer might not be in the need of that instead of the 3 N’ 1. I rewired the freezer as delivered and the compressor doesn’t start at all. Instead, I hear noise coming briefly from a 6″ capacitor which is what I thought was the defective part, and then it all shuts down. I had presumed that the capacitor was a start capacitor which is why I got the 3 N’ 1 in the first place. But information about this freezer model is unavailable and I don’t have enough knowledge to figure it out. Oh well….
Just in case: I had a similar problem on a regular refrigerator. Turns out the fan motor in the freezer compartment was burnt and was taking much more than the 200mA it is rated for.
Replaced the fan, now runs alright.
Hypothesis: by drawing way too much current, the motor didn’t leave enough for the controller to turn the compressor relay on, and the controller endlessly tried to restart, briefly turning the relay on. On the compressor, the start relay prevents the compressor from restarting. The compressor start winding isn’t energized, and the run winding cannot start the compressor on its own; the current flowing through the run winding only heats it.
Hi, in my haier refrigerator I faced issue. I replaced new voltage regulator and relay, it worked fine for approximately 15 days. Then there some kind of loose connection in neutral wire at main supply, I thought due to that relay has gone and corrected that neutral wire. Now only relay I replaced as it was not showing continuity, as soon as I switched on again relay failed. My question is that weather it is problem of incoming supply or is there problem with compressor which is drawing more current, can anyone help please
I just picked up a hard start kit. I’m curious though, I’ve seen some on line that have connectors to install the overload capacitor. The one I bought and the one you have in the article don’t have these connections. Isn’t this a concern?
Where do the remaining black wires go connected
I have a 2 year old Frigidaire that stopped working in both the freezer and fridge compartments. I replaced the start relay and it fired right up. Both fans turned on (in freezer and at compressor area). I go to check the fridge after a few hours and I don’t hear anything running again. I leave a cup of water in the freezer overnight and upon checking it, it was still liquid. What is causing my 2 year old fridge to blow start relays?
My 3 in 1 kit is not getting power with the instructed method how do I connect the kit to a refrigerator that runs with a run capacitor
In article, author instructs, ” … Just remember to remove the old components which may be bad first. I’ve actually seen that before.” ;-p
So it is determined that such a set of processes can be done to extend the life of the refrigerator?
I have a 2016 Samsung refrigerator/freezer. My refrigerator cools and functions fine but my freezer stopped cooling. I pulled the panel off the back and cleaned the coils very well. The compressor is very warm almost hot to the touch. The fan does blow onto the compressor I noticed when I had the back panel off. What could you recommend to me? Thank you
I replaced my own compressor and it can still work now, which is great.
Do you connect the 2 black power wires from my 810,3 in 1 supco start up kit to the thermostat wires on my pc board or to the main black & red power wires. I have a Ybeier fridge freezer in my Winnebago which is an Aldi Chinese made 12 /24 volt 118 litre fridge It has a pc board attached the wire connections seem dodgy Everything works fans compressor gets hot but no cold in fridge or freezer I’ve adjusted everything.
My supco 810,doesn’t work on my Ybeier upright 118 litre 12 volt fridge freezer it clicked a few times but nothing so I connected the pc board back & bypassed the thermostat on c&t terminals with a join wire & now the compressor gets warm at least both fans work but still no cold I might just put a new compressor in it Apparently the compressor used to get really hot because I didn’t know to turn on the cooling fan switch.
The freezer stopped working, no sound nothing dead. I ordered a new start relay switch. I checked the over load with my multi meter it tested good. all parts were installed and the freezer would not run.
I then installed a 3 in 1, the freezer started and runs great. The only problem is it keeps running. The thermostat was connected to the relay and overload switches that have now been removed.
My question is, How do I connect the thermostat to the 3 IN 1 so the freezer in not running continuously
can i start my compressor without capacitor and thermostart
Disconnected all the wiring and thermostat. Hooked 120 to the start relay and ran from a push pin timer and adjusted for cooling. Works great.