EW Plus 974
EW Plus Series • Refrigeration Controller
Quick Info
Output Functions
Universal controller for cold rooms and refrigeration units with defrost and fan control
Technical Specifications
Display & Interface
| Display Type | LED |
| Display Digits | 3 |
| Buttons | 4 |
| LED Indicators | Compressor, Defrost, Fan, Alarm |
Power Supply
| Voltage | 230V AC |
| Voltage Range | 100-240V AC |
| Frequency | 50/60Hz |
| Power Consumption | 3VA |
Sensor Inputs
| Probe Inputs | 2 |
| Probe Type | NTC 10K |
| Temp Range | -50 to 110°C |
| Accuracy | ±0.5°C |
Relay Outputs
| Relay Outputs | 3 |
| Relay Rating | 8A/250VAC |
Physical
| Panel Size | 32x74 mm |
| Depth | 60 mm |
| IP Rating | IP65 (front) |
| Weight | 95 g |
Operating Conditions
| Operating Temp | -5 to 55°C |
| Storage Temp | -25 to 70°C |
Wiring Terminals
| Terminal | Function | Type | Wire Color |
|---|---|---|---|
| 1 | Power L (Live) | Input |
brown
|
| 2 | Power N (Neutral) | Input |
blue
|
| 3 | Probe 1 (+) | Input |
red
|
| 4 | Probe 1 (-) | Input |
white
|
| 5 | Probe 2 (+) | Input |
red
|
| 6 | Probe 2 (-) | Input |
white
|
| 7 | Digital Input | Input |
gray
|
| 8 | Common (DI) | Input |
gray
|
| 9 | Relay 1 NO (Compressor) | Output |
black
|
| 10 | Relay 1 COM | Output |
black
|
| 11 | Relay 2 NO (Defrost) | Output |
orange
|
| 12 | Relay 2 COM | Output |
orange
|
| 13 | Relay 3 NO (Fan) | Output |
green
|
| 14 | Relay 3 COM | Output |
green
|
Important: Always disconnect power before wiring. Verify terminal numbers with the actual controller label before connecting.
Parameter Settings
| Code | Parameter | Range | Default | Description |
|---|---|---|---|---|
| SET | Setpoint | -50 to 110 | 5 °C | Temperature setpoint |
| Hy | Differential | 0.1 to 25.5 | 2 °C | Switching differential |
| LS | Low Setpoint Limit | -50 to SET | -50 °C | Minimum setpoint limit |
| US | High Setpoint Limit | SET to 110 | 110 °C | Maximum setpoint limit |
| Ot | Probe Calibration | -12.0 to 12.0 | 0 °C | Temperature probe offset |
| P2P | Probe 2 Present | 0=No, 1=Yes | 0 | Enable second probe |
| OA | Probe 2 Calibration | -12.0 to 12.0 | 0 °C | Evaporator probe offset |
| dFt | Defrost Type | 0=Off, 1=Electric, 2=Hot Gas | 1 | Defrost heating method |
| dt | Defrost Duration | 0 to 255 | 30 min | Maximum defrost time |
| dCt | Defrost Count | 0 to 24 | 4 /day | Number of defrosts per day |
| dOH | Defrost Start Time 1 | 0 to 23 | 6 hour | First defrost time |
| dSt | Defrost Stop Temp | 0 to 50 | 10 °C | Defrost termination temperature |
| Fdt | Fan Delay Time | 0 to 255 | 0 min | Fan delay after defrost |
| FCO | Fan at Comp Off | 0=Off, 1=On | 1 | Fan operation when compressor is off |
| ALU | High Alarm Temp | SET to 110 | 15 °C | High temperature alarm setpoint |
| ALL | Low Alarm Temp | -50 to SET | -5 °C | Low temperature alarm setpoint |
| AFd | Alarm Delay | 0 to 255 | 60 min | Alarm activation delay |
Error Codes
Solution: Check probe wiring and connections
Solution: Check evaporator probe wiring
Solution: Check refrigeration system operation
Solution: Check setpoint and system operation
Solution: Normal operation, wait for completion
Solution: Reset to factory defaults or replace controller
Frequently Asked Questions
Press SET button for 5 seconds until first parameter code appears
Press UP and DOWN buttons simultaneously for 3 seconds
Press SET for 5 seconds, scroll to "rES" parameter, set to 1
Check compressor delay time (dOn parameter), temperature differential, and relay connections
Alternative Models (Cross Reference)
Manufacturer Information
Brand: Eliwell
Country: Italy
Parent: Schneider Electric