Freezer thermostat issue.

[Dustcap]

Hi all.
I have a CDA freezer which wasn’t keeping cool recently. Decided I would try an inexpensive thermostat before going further.
The thermostat which came out of the freezer has 4 wires/connectors (black, brown, red & earth. The new thermostat only has 3 spades for connecting wires. Assuming it’s the wrong piece I Tried returning it but the seller is useless so spent another £15 on a second thermostat from another company.
This one also only has 3 spaces for connecting wires and is the same thermostat as previously sent.
Can this be a replacement or have they both got it wrong. I definitely ordered the correct part number in both cases but they sent another part number.

 

[AC Power]

It appears the new thermostat does not require a ground wire connection. This is fine, as the thermostat's chassis is grounded once it's screwed into it's original location. So, you wouldn't re-attach the green/yellow wire to anything.

If this doesn't help, take a few more surround pictures, and identify what thermostat your showing (old or new)?

 

[Dustcap]

It appears the new thermostat does not require a ground wire connection. This is fine, as the thermostat's chassis is grounded once it's screwed into it's original location. So, you wouldn't re-attach the green/yellow wire to anything.

If this doesn't help, take a few more surround pictures, and identify what thermostat your showing (old or new)?

Thanks for the response.
So which wire do I put on the ‘earth’ side connector?
the old thermo has the earth on one side and other three wires on the other side.
the new thermo has just two on the other side so which wire replaces the earth side connection?

 

[AC Power]

The earth side wire is the green/yellow.

On the other side (where there are two wires), it doesn't matter which goes on which terminal....it's just a switch, it'll work either way.

 

[Dustcap]

The earth side wire is the green/yellow.
[/QUOTE.
No problem
Understand that


QUOTE="AC Power, post: 1742794, member: 12486"]
On the other side (where there are two wires), it doesn't matter which goes on which terminal....it's just a switch, it'll work either way.

ok but I have three wires (the previous thermo had 4 connections). Which one should I leave off ? Red/black or brown?

 

[AC Power]

The old thermostat was likely equipped with a "form C" set of contacts, that is C, NO, and NC (three terminals) While there are wires on all three terminals, it is possible they are only using the C and NO terminals, leaving the NC unused. I have seen many times, wiring attached to terminals that NOT BEING used. It's possible the manufacturer is using the NC terminal on other models of washers, but NOT on yours. In an effort to simplify manufacturing processes, they will wire ALL machines leaving the factory with 3-wire thermostats, even though some of the models don't use the third (NC) wire.

Your new thermostat in likely only equipped with "form A" contacts, that is, C and NO terminals, the only ones you likely need. Which two wire colors those are? I don't know. As I don't suspect you have a multi-meter (or a tester for continuity), I can't say decisively which two wires to use. I could suggest you try different combinations, but that's unsafe.

If you have the time, and a few $$$, buy your self a small cheap "continuity" tester. You can make one, they are VERY easy. YouTube it. I can help you after you have a CONTINUITY TESTER. With that tester, you (and myself) will be able to determine the C, NO, and NC of your old thermostat, and also verify the operation of both old and new thermostats (be it the old works or not, and confirm the operation of the new thermostat). The identification of C, NO, and NC (as shown below) is critical in identifying the wiring arrangement of the old thermostat (unless, of course, you have the manufacturers electrical wiring schematics...if you do, send them to me).

 

[Dustcap]

Yes I do have a multimeter with continuity.

 

[AC Power]

Oh, wonderful! Ok, put your meter to that setting, that is, continuity. TEST the meter: Touch the two test leads from the meter together, you should see the meter respond to recognized continuity, a beep, a light, or a reading of 0 ohms. The response from the meter when you tough it's two leads together indicates CONTINUITY.

Perform this test with the old thermostat turned entirely to the CCW position.

OLD THERMOSTAT:
1) Identify the terminal screws that HAD the black, red and brown wired connected. (Mark them: Sharpie, felt pen, whatever...)
2) With your meter, touch your test leads to the terminals where the black and brown were previously connected. Does your meter identify continuity? (audible beep, visual light, or an ohm reading of zero). YES/NO
3) Again, with your meter, touch your test leads to the terminals where the black and red were previously connected. Does your meter identify continuity? YES/NO
4) And, with your meter, touch your test leads to the terminals where the brown and red were previously connected. Does your meter identify continuity? YES/NO

Perform this test with the old thermostat turned entirely to the CW position.

OLD THERMOSTAT:
1) With your meter, touch your test leads to the terminals where the black and brown were previously connected. Does your meter identify continuity? YES/NO
2) Again, with your meter, touch your test leads to the terminals where the black and red were previously connected. Does your meter identify continuity? YES/NO
3) And, with your meter, touch your test leads to the terminals where the brown and red were previously connected. Does your meter identify continuity? YES/NO

Perform this test with the new thermostat turned entirely to the CCW position.

1) On the only two terminals you've available (L and Ex), do you get continuity? YES / NO

Perform this test with the new thermostat turned entirely to the CW position.

1) On the only two terminals you've available (L and Ex), do you get continuity? YES / NO

Post your results in here, and I will show you the connections to the new thermostat accordingly. I will make every effort to return as soon as possible to assist.

 

[Dustcap]

Ok
Before I start I note that the old thermostat dial is loose and offers no resistance when turning. The new thermostat dial offers resistance

dial in CCW position.

With your meter, touch your test leads to the terminals where the black and brown were previously connected. Does your meter identify continuity? No continuity (no beep).

Again, with your meter, touch your test leads to the terminals where the black and red were previously connected. Does your meter identify continuity? No continuity (no beep)

And, with your meter, touch your test leads to the terminals where the brown and red were previously connected. Does your meter identify continuity? Yes continuity. (Beep).


thermostat in full CW position.

With your meter, touch your test leads to the terminals where the black and brown were previously connected. Does your meter identify continuity? No continuity. (No beep)

2) Again, with your meter, touch your test leads to the terminals where the black and red were previously connected. Does your meter identify continuity? No continuity. (No beep)

3) And, with your meter, touch your test leads to the terminals where the brown and red were previously connected. Does your meter identify continuity? Continuity (beep)

On the new thermostat on both fully CW and CCW position I get continuity.

 

[AC Power]

No mechanical resistance when rotating the old t-stat? Ok, Thanks.

Notwithstanding the physical feeling, we know for sure the old stat is dead as the status of the form C contacts are not changing upon manual operation of the sta

Ok, isolate the brown wire, in other words, just wire a wire connector (wire cap, wire nut, marrette, etc...) on it. It won't be used. Use ONLY the red and black conductors on the new thermostat. Put them on your only two remaining terminals on the new stat. It does not matter which manner/way you put them, there is no "backwards" with a switch.

So in the end, you should have the red and black wired ONLY attached to the new stat, with the grn/yel and brown wire capped off as they are unsued.

Try your freezer now.

Let me know, and Good Luck!