Ouman TMO/NTC10
- Type: NTC 10 kΩ (25 °C)
- Measurement range: -40 → +80 °C
- Accuracy: ±0.5 °C (0 → +60 °C)
- IP: IP54 (dust and rain-splash resistant)
Applications
Ouman TMO/NTC10 is the key input for weather compensation in Ouman controllers. The sensor reads outdoor air temperature and feeds the controller, which sets the flow-water setpoint based on the heating curve. Used in almost every Ouman substation schematic — multi-family substations, commercial building control assemblies, gas boiler systems and AHU with water coils. Delivery across the EU.
Technical specifications
| Parameter | Value |
|---|---|
| Code | OMA0015 |
| Model | Ouman TMO/NTC10 |
| Sensor type | NTC thermistor, 10 kΩ (25 °C), Beta ≈ 3977 K |
| Measurement range | -40 → +80 °C |
| Accuracy | ±0.5 °C (0 → +60 °C), ±1 °C over the remainder |
| Output signal | Ω (resistance) — analogue input to the Ouman controller |
| Time constant | ≈ 10 min (in outdoor conditions) |
| Connection | Terminals inside the housing (2-wire unshielded run up to 100 m) |
| Protection class | IP54 |
| Mounting | On the external wall, N/NW side, away from direct sun and heat sources |
| Housing | White ABS plastic, UV-resistant |
| Compatibility | Ouman A203, C203, C202L, EH-105, S203 and other NTC10 controllers |
Designer note
Mount the sensor on the north or north-west side, shielded from direct sun. A common failure mode: on spring/autumn mornings the sun can heat the sensor to +15 °C while actual air is -5 °C — the controller then thinks it is warm and under-opens the valve. The second common mistake is mounting above a heating grate or on a recessed entrance where the air is stagnant.
When to choose Ouman TMO/NTC10
- New installation of an Ouman controller (A203, C203, EH-105) — sensor required for weather compensation
- Replacement of a legacy outdoor sensor in an Ouman system
- Whenever the controller reads NTC 10 kΩ (not PT1000)
- Compatibility: Ouman A203 / C203 / C202L / EH-105 / S203. Not compatible with Danfoss ECL (uses PT1000 — order Danfoss ESMT instead).
B2B delivery and logistics
- Delivery across the EU (from warehouse in Vilnius, LT)
- Competitive B2B pricing for projects and bulk orders
- 30-day payment terms for companies (per contract)
- Free technical consultation on sensor installation
Official Ouman catalog: ouman.fi/tuote/tmo
FAQ
Does TMO/NTC10 fit Danfoss ECL controllers?
No. Danfoss ECL 210/310 and other Danfoss controllers use PT1000 sensors (Danfoss ESMT outdoor range). NTC 10 kΩ and PT1000 are not interchangeable. Ouman TMO fits only Ouman and some other NTC10 controllers (certain Belimo and Fidelix models).
What is the maximum cable length?
Recommended up to 100 m of unshielded 2×1.5 mm² cable. For longer runs use shielded cable to suppress electromagnetic noise. The cable must not run parallel to 230 V power cables inside the same conduit.
How to test whether the sensor works?
Power down the controller, disconnect the sensor wires and measure resistance with a multimeter. At 0 °C ≈ 32.6 kΩ, at 20 °C ≈ 12.5 kΩ, at 25 °C = 10 kΩ (nominal). Deviation > 10 % — replace the sensor.
Can the cable be extended?
Yes. The NTC signal is tolerant to conductor resistance (nominal 10 kΩ is much larger than a few ohms of cable resistance). Use standard 2×1.5 mm² cable up to 100 m; for longer runs use shielded twisted pair.
