The 22CT-52H is a Belimo active 24V cable-out temperature transmitter with a 2" stainless steel bullet probe, a Pt 1000 sensing element, and 0–5V or 0–10V (jumper-selectable) output. The transmitter is integrated into the cable line — no junction box on the duct or pipe. The included 6.5 ft plenum-rated cable (24 VAC/VDC power and the analog signal) lands directly at your controller panel. Eight jumper-selectable ranges (S0–S7) deliver the right resolution for your application.
Duct or pipe insertion temperature sensing where you want a clean panel-side termination without a junction box on the duct, AND you want an active 0-10V or 4-20mA output. Pair with a thermowell for chilled water, hot water, and condenser water immersion.
Key Features
Onboard jumper selects one of eight measuring ranges (S0–S7), letting you narrow the output span to your actual monitoring window for higher analog resolution. Factory default is S0 (-30 to 130°F) — change in the field with no tools beyond what you already carry.
Single voltage output with onboard jumper to switch between 0–5V and 0–10V for matching your controller's input expectations. Minimum load resistance 5 kΩ. Drives modern BAS analog inputs, mixing controllers, and PLC I/O cards directly.
21.6–26.4 VAC or 13.5–26.4 VDC; 0.8 VA / 0.4 W. Pluggable spring-loaded terminal block for fast wiring; lifts out for bench-side termination, snaps back into the housing.
Pt 1000 1/3 DIN platinum RTD element delivers ±0.9°F accuracy at 70°F (S2 / S4 ranges). Long-term stability ±0.07°F per year — no field calibration required.
Cable carries both 24V power and the analog signal back to your panel — no junction box on the duct or pipe. Cable jacket and probe both rated for plenum installation.
Industry-leading factory warranty backed by Belimo's worldwide service network.
Selectable Measuring Ranges (S0–S7)
Eight ranges are available via onboard jumper. Select the range whose span best matches your monitoring window — narrower ranges deliver higher analog resolution. The factory default is S0 (-30 to 130°F).
| Setting | Range (°F) | Range (°C) | Note |
|---|---|---|---|
| S0 | -30 to 130°F | -50 to 50°C | Factory default |
| S1 | 0 to 250°F | -10 to 120°C | |
| S2 | 40 to 140°F | 0 to 50°C | |
| S3 | 30 to 480°F | 0 to 250°C | |
| S4 | 0 to 100°F | -15 to 35°C | |
| S5 | 40 to 240°F | 0 to 100°C | |
| S6 | 40 to 90°F | -20 to 80°C | |
| S7 | 0 to 150°F | 0 to 160°C |
Technical Specifications
| Specification | Detail |
|---|---|
| Sensor Style | 2" Bullet Probe Temperature Transmitter (Active) |
| Measured Value | Temperature |
| Sensing Element | Pt 1000 1/3 DIN platinum RTD |
| Output Signal | 0–5V or 0–10V (jumper-selectable) — min. 5 kΩ load resistance |
| Multirange | 8 jumper-selectable measuring ranges (S0–S7); see table above |
| Default Range | -30 to 130°F (S0) (factory setting) |
| Accuracy | ±0.9°F (±0.5°C) at 70°F (21°C), measured on S2 / S4 ranges |
| Long-Term Stability | ±0.07°F per year (±0.04°C per year) |
| Time Constant τ (63%) | Air: ~30 s @ 6 m/s; Water (with thermowell): typical 17 s |
| Application | Air or water (with thermowell) — duct/pipe insertion |
| Mounting | Cable-out, 2" stainless steel probe, 6.5 ft plenum cable |
| Power Supply | 24 VAC/VDC (21.6–26.4 VAC, 13.5–26.4 VDC) |
| Power Consumption | 0.8 VA AC / 0.4 W DC |
| Electrical Connection | Pluggable spring-loaded terminal block, max 2.5 mm² |
| Cable Entry | 1/2" NPT conduit adapter included; cable gland with strain relief, ø6...8 mm |
| Housing | UV-resistant polycarbonate, orange — UL94 5VA |
| Enclosure Rating | NEMA 4X / IP65 housing on the in-line transmitter, sealed probe; UL 2043 plenum compliant cable |
| Protection Class | IEC/EN III, Protective Extra-Low Voltage (PELV); UL Class 2 supply |
| UL Approval | cULus per UL60730-1A/-2-9, CAN/CSA E60730-1/-2-9 |
| UL 2043 Compliance | Suitable for use in air plenums per NEC 300.22(C) and IMC Section 602 |
| Manufacturer | Belimo |
| Manufacturer Part Number | 22CT-52H |
| Warranty | 5-year factory warranty |
What's In the Box
- 22CT-52H active in-line temperature transmitter with 2" stainless probe and 6.5 ft plenum cable
Documentation
Frequently Asked Questions
What output signal does the 22CT-52H provide?
0–5V or 0–10V (jumper-selectable), with min. 5 kΩ load resistance. The voltage output is jumper-selectable between 0-5V and 0-10V on the same transmitter — set with an onboard jumper to match your controller's input expectations.
How do the 8 selectable measuring ranges work?
An onboard jumper selects one of 8 measuring ranges, S0 through S7, each spanning a different temperature window. The factory default is S0 (-30 to 130°F), the widest range — useful when you don't yet know what range you need. Once you know your actual monitoring window, switching to a narrower range (e.g. S2 = 40-140°F for domestic hot water) gives you higher analog resolution because the same 0-10V or 4-20mA output span maps to a smaller temperature range. See the Selectable Measuring Ranges table on this page for all 8 options.
Does this need 24V power?
Yes. The 22CT-52H is an ACTIVE transmitter — it requires 24 VAC or 24 VDC power (21.6-26.4 VAC or 13.5-26.4 VDC). Power consumption is 0.8 VA AC / 0.4 W DC. This is the key difference from the passive 01-series equivalent: the 01-series sends raw resistance to the controller, while the 22-series outputs a scaled voltage or current after onboard signal conditioning. The advantage is compatibility with controllers that don't have Pt 1000 input curves; the cost is the need to provide 24V power to each sensor.
Can I use this in a water or chilled-water line?
Yes — pair the 22CT with a matching length thermowell from the A-22P-A.. series for direct immersion in chilled water, hot water, condenser water, and process loops. For air-only duct insertion, no thermowell is needed.
How is this different from the passive 01CT?
The 01CT family is a passive resistance temperature sensor — it sends raw Pt 1000 (or NTC, Ni 1000) resistance to your controller, which must have a matching input curve. The 22CT family is an active 24V transmitter — it applies onboard signal conditioning and outputs a scaled 0-10V or 4-20mA signal. Choose passive when your BAS has Pt 1000/NTC inputs and you want fewer parts and no power supply concerns. Choose active (this product) when your BAS only accepts voltage/current analog inputs, when you need long cable runs (4-20mA versions are immune to voltage drop), or when you want the jumper-selectable range narrowing for higher resolution.
Does it work with my BAS?
Any BAS controller with a 0–5V / 0–10V analog input will read this transmitter directly. Set the controller input scale to match the selected measuring range (e.g., for S0 default, scale your input as -30°F = 0V/4mA, 130°F = 10V/20mA). No special curve or driver needed — it's a standard linear analog signal.
- Sensor Type:
- Probe Only
- Output Signal:
- Temperature Only
- Output Style:
- Active Transmitter (0-10V)
- Power:
- 24 VAC/VDC
- Temperature Element:
- Active Transmitter (0-10V)
- Sensing Element:
- Pt 1000 1/3 DIN
- Multirange:
- 8 Selectable Ranges (S0-S7)
- Default Range:
- -30 to 130°F (S0)
- Humidity Element:
- None
- CO2 Element:
- None
- VOC Element:
- None
- Display:
- No Display
- Setpoint:
- No Setpoint
- Override:
- No Override
- Supported Protocols:
- None (analog)
- Enclosure:
- NEMA 4X Enclosure
- Probe Length:
- 2 Inch
- Lead Length:
- 6 Foot Plenum Rated Cable
