Description

1. What the board does Part number CED-TVS-24 (24 VDC) and CED-TVS-110 (110 VAC) clamp surges to < 40 V in < 1 ns, protecting:

• 32 IR receiver diodes (typ. 5 V reverse)
• 5 V logic supply and UART lines
• 24 V/110 V power input to the curtain head Peak power: 1 500 W (8/20 µs pulse), 10 000 surges @ 500 V before –3 dB degradation Isolation: 2 kV between power and signal earth Temperature: –40 °C to +85 °C, IP20 when DIN-rail mounted

2. Safety first—lock-out & verify TVS boards sit on the same 24 VDC or 110 VAC rail that feeds the door operator. Lock the controller disconnect, hang a lock-out tag and wait 60 s for the rail to fall below 5 V. Keep the new Nanjing Zhuye TVS board in its anti-static bag until mounting—TVS diodes can be triggered by 50 V static.
3. Mechanical mounting—keep the leads short Snap the PCB onto 35 mm DIN rail inside the controller or the curtain head. Maintain 50 mm clearance above and below; every 10 °C rise halves varistor life. If the head is < 60 mm deep, mount vertically with terminals down—this allows convection and keeps surge currents away from the IR PCB. Nanjing Zhuye supplies a free DIN clip (NY-DIN-TVS) and a 0.5 m shielded pre-wired harness (NY-HAR-TVS) for plug-and-play replacement.
4. Wiring map (print and stick inside head) 24 V model: +24 V (red), 0 V (black), shield to PE at controller end only
   110 V model: L (brown), N (blue), PE (green/yellow)
   Signal side: UART-RX (yellow), UART-TX (green), 0 V logic (white), shield to curtain PCB earth pad
   Torque: 0.5 N·m for 0.5 mm², 0.8 N·m for 1.5 mm²
5. Power-up & clamp test Apply rated voltage; green “PWR” LED steady.
   With a handheld surge generator (500 V, 1.2/50 µs) inject L-PE: oscilloscope at curtain 5 V rail must show < 40 V peak and < 100 ns rise.
   Residual voltage > 45 V indicates degraded TVS—replace board immediately.
   A USD 120 tester pays for itself the first prevented curtain failure.
6. In-service monitoring (24 V model only) On-board comparator drives a red “FLT” LED if clamp voltage exceeds 39 V for > 1 µs.
   LED latches until power-cycle; connect N/O contact to BMS for remote “surge counter”.

50 recorded surges schedules replacement even if LED is still off—metal-oxide grains are beginning to fracture.

7. Temperature & lifetime model Metal-oxide varistor (MOV) degradation follows cumulative energy.
   CEDES field data: Light site (office park, <10 surges/year @ 500 V) – 0.05 J per strike, life ≈ 25 years. Medium site (high-rise, 50 strikes/year) – 0.2 J per strike, life ≈ 10 years. Heavy site (tropical rooftop, 200 strikes/year) – 0.5 J per strike, life ≈ 4 years. Capacitor C1 (4.7 µF, 50 V) is 105 °C, 2 000 h rated; at 55 °C Arrhenius predicts 32 kh—longer than MOV, so MOV sets the replacement interval.
8. Preventive inspection checklist Monthly: visual LED, wipe varistor face with dry cloth. Quarterly: clamp test with 500 V generator; residual > 45 V schedules replacement. Annually: megger L-PE > 100 MΩ; < 10 MΩ indicates carbon track. Bi-annually: torque test power terminals; vibration loosens them, causing arcing and fault “E-CURT”.
9. Rapid swap (downtime < 3 min) a) Power down, lock-out, wait 60 s. b) Photograph wire colours with phone. c) Remove DIN clip, slide old board out. d) Insert new Nanjing Zhuye CED-TVS, snap onto rail. e) Restore harness, torque 0.8 N·m. f) Power up, verify green LED, run 500 V clamp test. g) Log serial number and surge count; return old unit for recycling.
10. Recycling & sustainability Nanjing Zhuye offers prepaid DHL labels inside every carton.
    Returned boards are stripped: zinc oxide varistors are refined for metal recovery, copper inductors remelted, plastic housing re-granulated.
    One recycled TVS board saves 1.1 kg CO₂—enough to power the same curtain for a month.