Description

Otis elevator door machine motor PM81855D Brief Introduction

1. What PM81855D Really Is

• Power: 1.5 kW, 24 VDC, 65 A peak, 20 A continuous
• Torque: 6 Nm rated, 18 Nm peak (300 %) for 5 s
• Speed: 0–180 rpm, 1,024 ppr encoder, ±1 rpm accuracy
• Motor: 3-phase PM synchronous, 8-pole, <55 dB(A) at 1 m
• Regeneration: 4-quadrant IGBT feeds braking energy back to 24 V bus — saves 18 % power
• Protection: IP55 aluminium housing, -25 °C to +70 °C, vibration 20 g
• Size: 200 × 100 mm — fits inside any door operator top box

2. Where It Is Used

• Otis Gen2-R2®, Gen2-Life®, SkyRise® 1.75–4.0 m s⁻¹ with PM machines 35–55 kW
• Thyssen TCM-MC3 retrofit kits
• Chinese super-MRL controllers with 24 VDC door bus
• Suitable for centre-opening or side-opening doors 900–1,400 mm clear width

3. Commissioning – 20-Minute Plug-and-Play

1. Remove old motor — undo 4 M6 screws; unplug 8-way Molex.
2. Mount PM81855D — slide into operator bracket until latches click; earth strap to PE.
3. Connect plugs:
   • J1: 24 VDC (red/black)
   • J2: motor U/V/W (shielded)
   • J3: encoder A/B/Z + 5 V
   • J4: CAN H/L + shield
   • J5: brake resistor B+/B- (4 Ω, 200 W)
4. Apply 24 V — green LED blinks 1 Hz while loading parameters, then steady.
5. Auto-tune: press and hold TUNE for 3 s; motor runs one open/close cycle, stores stator resistance and encoder offset.
6. Run 5 cycles — verify current <12 A, torque ripple <5 %, stop accuracy ±1 mm.

4. Daily Operation – What the Motor Actually Does

• Updates torque every 62.5 µs; stop jerk <0.5 m/s³ — passengers feel nothing
• Auto-compensates for door mass; learns rubber ageing every 24 h
• Built-in 24 h self-test — if encoder drift >0.5 mm, “Door Learn Fault” is logged
• Regenerative braking feeds 18 % of door energy back to 24 V bus — saves battery life
• Temperature sensor derates current above 70 °C — no summer shutdowns

5. Replacement Cycle & Preventive Maintenance

• High-traffic metro (>1,500 cycles day⁻¹) – blow dust every 3 months, replace motor every 6 years
• Shopping mall (600–1,000 cycles day⁻¹) – inspect annually, replace every 10 years
• Low-rise office (≤400 cycles day⁻¹) – inspect every 18 months, replace every 12 years

• Encoder count error >4 pulses per revolution
• Brake resistor temperature >120 °C with normal duty
• Vibration >65 dB(A) at 1 m during run
• Bearing temperature >65 °C after 10 min run
• EEPROM error 0xE2 after power dip (parameter corrupt)

6. Extending Life – 3 Pro Tips

1. Keep 24 VDC ±5 %; spikes above 30 V destroy the on-board buck converter
2. Torque motor lugs annually; loose connections cause arcing and ozone
3. Clean encoder disk monthly; brake dust creates false counts

7. Why Buy PM81855D from Nanjing Zhuye Elevator Parts?

• Factory-new, not refurbished; passes 4-hour burn-in at 60 °C and 2,000-cycle door test
• Firmware pre-flashed; matches Otis original checksum, no teach-in required
• Anti-static foam box + silica gel — safe for air freight
• Dual stock: 380 pcs Nanjing, 120 pcs Dubai — next-day delivery to 65 countries
• Bundle kit: motor + 4 Ω brake resistor + 3 m encoder cable — 8 % discount
• 24 months warranty against bearing wear or encoder drift
• 7×24 WhatsApp/WeChat video support; average response 10 minutes

Conclusion