Description

1. Part-number breakdown DAA26800CL3 = base SOM, 24 VDC, 48 outputs, 2 A per channel, IP20, –10 °C…+60 °C
   CL4 = CL3 + reinforced 4 kV isolation, built-in 0.5 A self-resetting fuse, hot-swap fan header, MTBF 90 kh @ 25 °C
   Both share 220 × 120 mm footprint, mass 0.38 kg
2. Safety first—lock-out & verify Board sits on 24 VDC logic but switches 110 V call contacts. Lock the main disconnect, hang a lock-out tag and wait 60 s for the rail to fall below 5 V. Keep the new NYE board in its anti-static bag until mounting—CMOS logic can latch at 15 V static.
3. Mechanical mounting—keep it cool Snap onto 35 mm DIN rail inside the controller or landing box. Maintain 50 mm clearance above and below; every 10 °C rise halves relay life. If the box is <100 mm deep, mount vertically with RS-485 down—this allows convection chimney. NYE supplies a free DIN clip (NY-DIN-CLx) and 10 mm thermal pad (NY-PAD-CLx) for shallow enclosures.
4. Wiring map (print and stick inside box) 24 V & 0 V: 2.5 mm², 105 °C silicone, torque 0.8 N·m
   Inputs: 48 × dry contact, 1 mm², torque 0.5 N·m
   Outputs: 48 × 2 A, 1 mm², common anode, 24 VDC max
   RS-485-A/B: twisted pair, 120 Ω termination at last board (DIP-1 ON)
   Fan header: 12 V 0.2 A, locked-rotor alarm
   Earth: 4 mm² green/yellow to box PE; logic leakage <1 mA
5. Power-up & self-test Apply 24 VDC; green “SYS” LED blinks 3 s, then steady.
   RS-485 link LED must light within 5 s; if flashing 1 Hz, address conflict—check DIP switches.
   Self-test: all outputs cycle, inputs toggle, fan runs 2 s. Any fail = red “FLT” LED + code on LCD.
6. Firmware & parameter download Otis SOM Tool (free) via RS-485.
   Default address: 0x30; change to site map.
   Upload parameter file (*.som) provided by NYE; checksum must match label.
   Save to flash (button “Burn”), then reboot. Wrong firmware triggers “E-SOM” — re-flash immediately.
7. Temperature & lifetime model Relay contacts: 1 million cycles; at 600 calls/day = 4.5 years.
   Flash memory: 100 k erase cycles, 20 year retention @ 25 °C.
   Capacitor C1 (100 µF, 35 V): 2 000 h @ 105 °C, 64 kh @ 45 °C.
   Translate to building traffic: Light traffic (office, 600 calls/day) – relays ≈ 4.5 years, flash ≈ 15 years, full board ≈ 10 years; inspect every 3 years. Medium traffic (mall, 1 200 calls/day) – relays ≈ 2 years, flash ≈ 8 years, full board ≈ 5 years; inspect every 2 years. Heavy traffic (metro, 2 400 calls/day) – relays ≈ 1 year, flash ≈ 4 years, full board ≈ 3 years; inspect every 6 months.
8. Remote monitoring (optional) RS-485 registers:
   0x00 = input status (48-bit)
   0x01 = output status (48-bit)
   0x02 = temperature (°C)
   0x03 = cycle counter
   0x04 = flash wear (%)
   Poll every 30 s; flash wear >80 % or temperature >70 °C schedules replacement.
9. Preventive inspection checklist Monthly: visual SYS LED, listen for relay click during call. Quarterly: measure 24 VDC ripple; >200 mV pp indicates supply fatigue. Annually: megger inputs to PE >100 MΩ; <10 MΩ indicates moisture ingress. Bi-annually: torque test 24 V screws; vibration loosens them, causing intermittent “E-SOM”.
10. Rapid swap (downtime < 3 min) a) Power down, lock-out, wait 60 s.
    b) Photograph wire numbers with phone.
    c) Remove DIN clip, slide old board out.
    d) Insert new NYE DAA26800CL3/4, snap onto rail.
    e) Restore wires in exact order, set DIP switches as photo.
    f) Power up, upload firmware, run self-test.
    g) Log serial number, flash wear, temperature; return old unit for recycling.
11. Recycling & sustainability Nanjing Zhuye offers prepaid DHL labels inside every carton.
    Returned boards are stripped: gold fingers go to certified refinery, plastic housing re-granulated, relay silver recovered.
    One recycled CLx saves 1.4 kg CO₂—enough to power the same landing for a week.