The 01CT-5QH01 is a Belimo passive cable temperature sensor with a NTC 20K thermistor sensing element on a 2" stainless steel probe and 6.5 ft of bare copper shielded plenum cable, black jacket. Use it in an air duct with a separate mounting flange (linked below), or as an immersion sensor with a Belimo thermowell for chilled water, hot water, and process loops. The cable jacket is rated to -13 to 167°F; the stainless steel probe handles the same range. The signal returns directly to the controller as a resistance — no 24V supply or signal conditioning required.
Duct air, supply and return air, and — with the matching length thermowell — direct immersion in chilled water, hot water, and condenser water. Compact in-line cable design fits clean conduit runs and panel terminations without an exterior junction box.
Key Features
Stainless steel sensing probe rated NEMA 4X / IP67. Suitable for duct air, mechanical-room environments, and — with a thermowell — direct fluid immersion.
Factory-trimmed NTC 20K element delivers stable long-term accuracy with no field calibration required.
Pair with the matching 2" Belimo thermowell (linked below) for direct immersion in chilled water, hot water, condenser water, and process loops.
Passive resistance returns directly to the controller — no 24V supply, no signal conditioning, no scaling required.
6.5 ft of bare copper shielded plenum cable, black jacket runs from the probe directly to the controller terminations — no exterior junction box on the duct.
Industry-leading factory warranty backed by Belimo's worldwide service network.
Technical Specifications
| Specification | Detail |
|---|---|
| Sensor Style | Cable temperature sensor with stainless steel probe |
| Measured Value | Temperature |
| Sensing Element | NTC 20K thermistor |
| Measuring Range | -13...167°F [-25...75°C] |
| Probe Length | 2" [50 mm] |
| Probe Diameter | 0.24" [6 mm] |
| Probe Material | Stainless steel |
| Cable | 6.5 ft [2 m] bare copper shielded plenum cable, black jacket, 22AWG, 2-wire, 300 V |
| Application | air, water (with thermowell) |
| Mounting | Separate mounting flange (sold separately) for duct, or thermowell for fluid immersion |
| Process Connection | Compatible with A-22D-A.. flanges (air) and 1/2" NPT thermowells A-22P-A.. (liquid) |
| Enclosure Rating | NEMA 4X / IP67 |
| Protection Class | IEC/EN III, Protective Extra-Low Voltage (PELV) |
| UL Approval | cULus per UL60730-1A/-2-9, CAN/CSA E60730-1/-2-9 |
| Power Required | None — passive resistance element |
| Weight | 0.14 lb |
| Manufacturer | Belimo |
| Manufacturer Part Number | 01CT-5QH01 |
| Warranty | 5-year factory warranty |
Compatible Accessories
Documentation
Frequently Asked Questions
Does this need 24V power?
No. The 01CT-5QH01 is a passive resistance temperature sensor — the controller reads its element directly through the analog input. No 24V supply or signal conditioner needed.
What sensing element is in the 01CT-5QH01?
The 01CT-5QH01 uses a NTC 20K thermistor. The first letter after '01CT-5' identifies the element: A=Pt 100, B=Pt 1000, E=Ni 1000 (JCI), L=NTC 10K Type II, M=NTC 10K Type III (Precon), Q=NTC 20K. Match this to your controller's input curve.
What does the probe length code mean?
The letter after the element code encodes probe length: H=2", L=4", P=8". This SKU has a 2" probe.
Why does this SKU end in '01'?
The '01' suffix denotes the bare-copper-conductor cable variant with a black plenum jacket, rated -13 to 167°F. The standard variant (no '01' suffix) has tinned-copper conductors with a green jacket and a wider -40 to 300°F range. Specify whichever matches your wire gauge / shield specification.
Can I use this on a water or chilled-water line?
Yes — pair the sensor with the matching length thermowell from the Compatible Accessories section above. For this 2" probe, see the 2" stainless or brass thermowells listed.
Does it work with my BAS?
Any BAS controller with a temperature input configured for the NTC 20K curve will read this sensor directly. See the linked Resistance Characteristics PDF for the full curve table at standard temperature points.
How is this different from the 01DT duct sensor?
The 01DT mounts in a NEMA 4X polymer enclosure on the duct exterior with terminals inside the box. The 01CT terminates directly via the cable — no exterior junction box, cleaner installs into a controller panel. Both use the same passive elements and the same family of thermowells when used for liquid immersion.
- Sensor Type:
- Probe Only
- Probe Length:
- 2 Inch
- Temperature Element:
- 20K Thermistor
- Lead Length:
- 6 Foot Plenum Rated Cable
- Enclosure:
- No Box
- Supported Protocols:
- None
- Humidity Element:
- None
- CO2 Element:
- None
- Setpoint:
- No Setpoint
- Override:
- No Override
- Display:
- No Display
