Installation Guide: Replacing TAM-125 Thermostat with RANCO K56 / K57 in Atlant Freezers
The TAM-125 thermostat (including the TAM-125-1M revision) is used in freezers and dual-compressor refrigerators made by Atlant (MXM, MM series, etc.). Excellent European replacements for this part are the RANCO K56-S1970 and RANCO K57-L2829 (2.5m capillary tube) thermostats.
1. Core Specifications Comparison
- Application: Freezers / Freezer compartments (LBP).
- Cut-out Temperature Range: -20°C to -26°C (depending on the dial setting).
- Additional Features: Supports high-temperature alarm indication (red "Alarm" light) when the temperature rises above -12°C to -15°C.
2. Wiring Re-pinning Diagram
Please pay close attention when reconnecting wires, as pinouts differ between the K56 and K57 series:
| TAM-125 Terminal | Option 1: RANCO K56-S1970 | Option 2: RANCO K57-L2829 | Wire Function |
|---|---|---|---|
| Terminal 3 | Terminal 3 | Terminal 6 | Common / Main Power Supply (Live / Line In) |
| Terminal 4 | Terminal 4 | Terminal 4 | Output to Freezer Compressor |
| Terminal 6 | Terminal 6 | Terminal 3 | Output to High-Temp Warning Light ("Alarm") |
| Terminal 8 | Not used / "Super Freeze" switch | Super Freeze mode indicator lamp wire (isolate or connect to switch if present) | |
| Housing (Ground) | Earth Terminal | Earth Terminal | Yellow-green ground wire connected to chassis |
3. Step-by-Step Installation Process
- Disconnect Power: Unplug the appliance from the 220V mains outlet.
- Remove Control Panel: Remove the protective control mask/housing, pull off the adjustment knob, and unscrew the thermostat mounting nut.
- Reconnect Wiring: Transfer the wires from the old TAM-125 to the new RANCO (K56 or K57) strictly following the selected column in the table above.
- Route Capillary Tube: Uncoil the capillary tube smoothly without kinks or sharp bends, and route it along the original path to the freezer evaporator. Gently loop any excess tubing (K57 features a 2.5m capillary) behind the panel.
- Reassembly: Secure the thermostat body with the mounting nut, then reattach the control panel and adjustment dial.
4. Post-Installation Verification
After powering on the freezer:
- In a warm compartment, the compressor should start immediately, and the red "Alarm" warning light should turn on.
- Once operating temperature is reached (after 2–4 hours), the red light must switch off, and the compressor should begin cycling on and off normally.
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