Selecting the wrong sensing point, control signal or switching device can produce unstable temperature control, false alarms, missed flow protection or unnecessary commissioning work.
Explore YONGFAN TC-8000 floating-point temperature controllers (0–40 °C / 0–99 °C), external NTC 10k thermistor sensors (0–150 °C, IP54), P74JA3 differential-pressure threshold switches (0.5–4 MPa), HFS paddle flow switches (15 bar), and packaged temperature/DP control cabinets.
TC-8000 outputs a 3-position floating pulse (drive open / closed / hold). Wiring it to an analog 0–10 V actuator results in zero movement.
Installing water temperature probes in low-flow pockets creates thermal lag, causing the controller to overdrive the valve and hunt wildly.
P74JA3 is an on/off threshold switch (pressure rising). Expecting a 4–20 mA continuous signal for pump VFD modulation fails.
Installing standard paddle flow switches on low-velocity bypass lines fails to trip the microswitch; baffle-type switches must be specified.
Three-position floating proportional temperature controller (drive open, closed, hold). Electronic version covers 0–40 °C; LCD version extends to 0–99 °C with ±1 °C accuracy. Operates on 24 VAC ±10%, 50/60 Hz, paired with external NTC 10k thermistor probes.
High-stability NTC 10k thermistor elements housed in flame-retardant PA enclosures. Documented operating range of 0–150 °C, max ambient 70 °C, IP54 protection, and cable options in 1.5 m, 3 m, 5 m, and 10 m lengths.
Pressure-rising threshold switching device with a published 0.5–4 MPa setting range. Operates on 24 VAC, handles medium temperatures from -20 to 120 °C, and connects via self-locking Φ6×1 mm copper capillary tubing.
HFS paddle switch provides SPDT microswitch status for water, air, and oil (-10 to 80 °C, 15 bar max, IP54, 100k cycles). Baffle-type switch detects low flows with 5–15 L/min start-up flow and 15–200 L/min maximum operating range (1.5 MPa max).
Packaged wall-mounted local control enclosures integrating proportional-integral controllers, step-down transformers, circuit breakers, digital LCD displays, backlights, power switches, and security locks.
| Device | Primary Function | Published Range or Limit | Output / Action Format | First Selection Input |
|---|---|---|---|---|
| TC-8000 Electronic | Temperature modulation | 0–40 °C adjustable range | Three-position floating proportional | Required temperature range & actuator signal |
| TC-8000 LCD | Wider-range temperature modulation | 0–99 °C · ±1 °C stated accuracy | Three-position floating proportional | Required setpoint range & display need |
| NTC Temperature Sensor | External temperature measurement | 0–150 °C · Ambient max 70 °C · IP54 | NTC 10k element for controller | Sensing location & immersion well need |
| P74JA3 DP Controller | Differential-pressure threshold control | 0.5–4 MPa setting · -20 to 120 °C | Contact action on pressure increase | Required DP threshold & switching logic |
| HFS Paddle Flow Switch | Flow proving / equipment protection | -10 to 80 °C · 15 bar · 100k cycles | SPDT microswitch | Pipe size & minimum flow velocity |
| Baffle Flow Switch | Low-flow threshold switching | Start-up 5–15 L/min · Max 15–200 L/min | NO / NC switch output | Expected circuit low-flow range |
| Temperature Control Cabinet | Packaged local temperature control | Integrated PI controller & transformer | Local controller with protection | Temperature sequence & connected load |
| DP Control Cabinet | Packaged local DP control | Integrated DP controller & transformer | Local DP controller with protection | DP control sequence & power supply |
Duct air temp, immersion water temp, DP threshold, or pipe flow proving.
0–40 °C (TC-8000 Electronic), 0–99 °C (LCD), or 0.5–4 MPa DP threshold.
Verify 3-position floating pulse (for VA actuators) or dry SPDT microswitch contacts.
Specify probe insertion depth, cable length (1.5/3/5/10 m), or control cabinet package.
YONGFAN controls engineers will verify sensor probe immersion wells, confirm floating actuator compatibility, and configure pre-wired control cabinets.
TC-8000 controllers are benchmarked against multi-point resistance simulation rigs to verify floating-pulse output accuracy.
Representative controllers are paired end-to-end with reference VA-series actuators to verify smooth closed-loop valve convergence.
Differential-pressure switches are calibrated on hydraulic test benches with contact make/break points certified.
Controllers ship in anti-static ESD packaging individually boxed with matched NTC temperature probes and wiring manuals.
Use TC-8000 when the actuator accepts a 3-position floating signal. The Electronic model covers 0–40 °C; LCD model covers 0–99 °C.
YONGFAN documents an external NTC 10k thermistor sensor for both TC-8000 versions, available in room-air, duct, and immersion probe styles.
Use the HFS Paddle-Type Flow Switch for main pipes, or the Baffle Flow Switch for low-flow circuits (5–15 L/min start-up).
The P74JA3 DP controller is configured for pressure-rising action to trigger bypass valve opening upon rising system ΔP.
Standard models ship in 7–14 working days; pre-calibrated project orders ship in 14–21 working days.
No. TC-8000 is a floating-point temperature controller for modulating valves. For FCU 3-speed fan control, use DB Thermostats.
No. P74JA3 is an on/off threshold switch. For continuous proportional pressure feedback to a VFD, specify an analog DP transmitter.
Controllers ship in protective ESD individual packaging with the specified NTC probe and terminal wiring schematics included.
TC-8000 modulates coil valves; it does not switch 3-speed FCU fans. Select DB series thermostats for room fan coils.
P74JA3 provides contact tripping on rising DP; it does not output continuous 0–10 V / 4–20 mA pressure curves for VFDs.
HFS flow switches prove contact closure; they do not measure flow rate or BTU energy. Use dedicated electromagnetic meters for billing.
Control cabinets are local packaged assemblies. Centralized plant sequencing requires multi-point DDC controller panels.
Send your control loop schematic, measured temperature/pressure ranges, actuator signal requirements, and safety switch parameters. YONGFAN application engineers will verify loop compatibility and provide complete wiring submittals.
