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DEVIreg™ 850 version IV is an advanced thermostat with LED display for outdoor ground or roof applications. Its sensors report both moisture level and temperature, giving optimal control of the heating system. It can handle up to 2 independent areas: a single system for roof or ground (1–4 sensors); a combination system of 1 ground and 1 roof system (2–4 sensors, min. 1 per system); or a dual system of 2 roof or 2 ground systems (2–4 sensors, min. 1 per system). In dual or combination systems you can prioritise between zones, for example if only limited power is available.
Features and applications
- Single, combination or dual zones
- Up to 4 sensors
- Moisture and temperature sensing
- Self-diagnosing programme
- Safety level adjustment
- Alarm function
Specifications
| Operation voltage — PSU 24 VDC | 180–250 VAC, 50–60 Hz / 24 VDC |
|---|---|
| Operation voltage — DEVIreg™ 850 IV | 24 VDC ±10% |
| Power consumption, max. — DEVIreg™ 850 IV | 3 W |
| Power consumption — roof sensor | 8 W (each) |
| Power consumption — ground sensor | 13 W (each) |
| Relay resistive load — System A / B relay | 15 A (3450 W) @ 230 V |
| Relay resistive load — alarm relay | 2 A @ 230 V |
| Inductive load each relay, max. | 1 A @ 230 V, power factor 0.3 |
| Sensing unit | DEVIbus™ connected moisture sensor(s) |
| Cable specification for terminals, max. | 1 x 4 mm² or 2 x 2.5 mm² |
| Ball pressure test temperature | 75 °C |
| Pollution degree | 2 (domestic use) |
| Controller type | 1C |
| Storage temperature | -20 °C to +65 °C |
| IP class | IP20 |
| Protection class | Class II |
| Dimensions (H/W/D) — PSU 24 VDC | 85 x 73 x 53 mm |
| Dimensions (H/W/D) — DEVIreg™ 850 IV | 85 x 105 x 53 mm |
| Mounting method | DIN rail |
| Weight | 720 g |
| Versions (languages) | Latin: GB, CZ, DE, DK, ES, EST, FI, FR, HR, HU, LT, LV, NL, NO, PL, SCG, SE, SI, SK, TR; Cyrillic: GB, BG, RO, RU |
Options and product codes
| Product code | Product name | Type | Size (mm) | Ambient temp. |
|---|---|---|---|---|
| 140F1085 | DEVIreg™ 850 IV | Without sensors, Latin languages | 85 x 105 x 53 | -10 to +50 °C |
| 140F1086 | Roof sensor | For DEVIreg™ 850, with sensor tube, cable 15 m | 15 x 24 x 216 | -50 to +70 °C |
| 140F1088 | Ground sensor | For DEVIreg™ 850, cable 15 m | Ø 93 x 98 | -30 to +70 °C |
| 19119977 | Sensor tube and cap | For DEVIreg™ 850 ground sensor | Ø 93 x 98 | -30 to +70 °C |
Data from the Heat Zone 2026 product catalogue. Check the current DEVI data sheet for your exact product code before installation. Need the PDF data sheet? Call 1800 519 654 or email info@heatzone.com.au.
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