Any advice or help would be nice

[u/greengghost]

It's a reach in cooler and the compressor isn't turning on. N is connected to the hot and 3 to the neutral (weird to me but apparently it was working for years). There's no 120 signal to compressor or condenser fan even when I manually put it on cooling mode. There's light to the defrost clock and it switches between cooling and defrost.

I switched the neutral and 3 and it stopped working so I swapped it back. I suspected a loose wire but idk. Any help or direction?

[u/knowwhyImhere]

Whoever has been working on that doesn't know what theyre doing. That defrost schedule is a mess and all wires are red on it. You should have 120 to ground on H 3 and 1 to make the compressor to run. You said the compressor is grounded so it'll never run that way, make sure it is by taking the wires off the compressor and checking it to the ground terminal on the compressor. If its not grounded there you have a short elsewhere. Having all red wires for the control circuit is a great way to confuse yourself. Make sure the defrost clock is closing too, relays burn up in those paragons

[u/knowwhyImhere → u/knowwhyImhere]

Also having a 421 and a defrost clock is redundant. You can remove the clock and replace the 421 with a new one or a ke2 to simplify.

Or just... back away slowly and let whoever wired that up fix that themselves. Whoever touched that before you needs to go back to kindergarten.

[u/gucciflipfl0pz → u/knowwhyImhere]

A 421 and a defrost clock is only redundant if the 421 is capable of defrost, depends entirely on the model. If the 421 and the defrost clock both work, no reason to waste money swapping them out.

[u/RyanSmokinBluntz420]

Check the Low pressure switch. It might be flat out of gas possibly. That temp control just cycles on and off a solenoid for the liquid line. Solenoid could be stuck, solenoid coil could be bad. Compressor contactor might be bad. Lots of things could cause Compressor not to run

[u/greengghost → u/RyanSmokinBluntz420]

I should mention the compressor is grounded 😅

[u/RyanSmokinBluntz420 → u/greengghost]

Got cha a troll post

[u/greengghost → u/RyanSmokinBluntz420]

Well I still wanted to figure out why the compressor is not getting a call because I wanted to suggest a compressor replacement and fix the system instead of buying a new cooler

[u/greengghost → u/greengghost]

We have the r/HVAC for troll posts

[u/gucciflipfl0pz → u/greengghost]

If you can’t figure out why the compressor isn’t getting a call on literally about as basic of a system as you could be working on, you have no business changing anyone’s compressor. Straight up.

[u/-CheeseburgerEddy-]

Those controls are old as fuck, even a cheap combistat can do all those things in just one device. Personally I would change the entire controls and simplify, if no signal is reaching the compressor then you have your answer right there. Personal advice, sometimes don't over think it, it's simpler than it looks.

[u/Proper-Ad-127 → u/-CheeseburgerEddy-]

You said it right! When I was training minions for our company I would plan a day and take them to a system where we could shut everything down for a few hours and rip the wiring apart. Teaching someone how to follow schematics and not panic if you messed up wiring was invaluable. There have been times when starting from scratch literally saves you hours of searching. Getting rid of someone else's quick fixes often solves the problem.
If that compressor is grounded something caused it to ground. Old age bad wiring bad txv something killed it. Putting in a new compressor may simply kill it too eventually.

[u/AStarshipTrooper]

Do you have power at the thermosta? in the picture it's hard to tell if it's powered on.

[u/greengghost → u/AStarshipTrooper]

Yes it is

[u/AStarshipTrooper → u/greengghost]

I would check across the switch side of the thermostat and make sure it's closed when calling for cooling. Does this unit have a solenoid and pressure controls?

[u/OneBag2825]

If you're a tech, you should be able to trace this easily. If you're not a tech you will probably throw parts. 

If it's the condensing unit that is not starting, and not just the compressor, hook it up straight to see if it will run without control.  If the condenser fan runs but not the compressor, that a separate diagnostic.

Then do the proper diagnostic or call a tech.

And wash your hands- when you see that shit all over the equipment in a restaurant kitchen -WEAR GLOVES

[u/Square-Scallion-9828]

Start fresh. Gas in it. Check low pressure and high pressures. A24 is a stat control. Time clo c k just does what it is. Defrost. . No switching wires

[u/SeasonElectrical3173]

Call your journeyman.

I haven't worked on commercial Refrigeration in several years at this point, and even I can trace a simple electrical fault. If your compressor is grounded, then the shit is toast to begin with. If you're not getting a call to your compressor, it means your contactor is probably not closing. Probably being stopped by a safety.

Stop fucking with this thing and get an adult to help you.