Description

1. Construction & ratings Core: grain-oriented silicon steel, 0.35 mm lamination, 94 % stacking factor. Windings: H-class (180 °C) copper, vacuum pressure impregnated (VPI) with polyester resin. Insulation: 4 kV RMS primary-to-secondary, 2 kV RMS layer-to-layer, UL 1446 class F file E318012. Taps: +5 % / 0 % / –5 % on 380 V primary; 0 % / –2.5 % on 220 V primary. Secondary: 110 VAC ±2 % @ 3.2 A, 24 VAC ±3 % @ 2.5 A, electrostatic shield between windings. Temperature rise: < 75 K at full load when ambient ≤ 40 °C. Weight: 11.5 kg; mounting centres 96 × 156 mm to DIN 41307.
2. Safety first—lock-out & verify Isolate the main three-phase supply and the 110 VDC drive bus—Mitsubishi controllers keep the bus hot even with mains off. Use a calibrated multimeter to confirm < 5 V between all phases and PE. Hang lock-out tags on both the machine-room disconnect and the car-top inspection box.
3. Removal of old transformer a) Photograph all wiring—Mitsubishi uses colour codes that fade with heat. b) Unscrew M8 mounting bolts; expect 9 kg weight—use a strap, not fingers. c) Label flying leads P1-P9 before cutting ferrules—wrong re-connection will back-feed 380 V into 110 V logic. d) Check insulation resistance with a 1 kV megger; < 100 MΩ indicates aged windings and justifies replacement.
4. Installing the Nanjing Zhuye X54DC-04 Mount on 10 mm vibration-damping pads (supplied). Torque M8 bolts to 18 N·m—over-tightening warps the core and increases audible hum by 10 dB. Maintain 50 mm clearance on all sides; every 10 °C rise halves insulation life. If the cabinet is < 80 mm deep, rotate the transformer 90 ° so oil-filled terminals face the door—this allows infrared scan without removal.
5. Re-wiring & tap selection Primary: connect incoming 380 V to taps 0-0 for nominal; if site measures > 405 V use –5 % tap to keep secondary within Mitsubishi ±5 % tolerance. Secondary 110 V: feed to CN1 on the P1 CPU board through 6 A ceramic fuse (Mitsubishi part FC-A6). Secondary 24 V: supply to door operator brake via rectifier bridge DB1; use 2.5 mm², 105 °C silicone wire. PE: bond the transformer frame stud to cabinet earth with 4 mm² green/yellow; this drains the electrostatic shield and prevents floating neutral shocks.
6. Power-up & no-load test Apply three-phase, measure: Primary current < 0.15 A (magnetising only). Secondary 110 V ±2 % line-to-line, no-load. Secondary 24 V ±3 %. Audible noise < 45 dB(A) at 1 m—higher pitch indicates loose laminations or foreign object.
7. Full-load heat run Connect a temporary 34 Ω, 1 kW resistor across 110 V to simulate logic + contactors; 24 V loaded with 9.6 Ω, 60 W. Run for 2 h; heat-sink temperature must stabilise < 90 °C (measured on core bolt head). Nanjing Zhuye units typically plateau at 82 °C in 40 °C ambient—well within class H insulation.
8. Lifetime model & replacement cycle Insulation life follows Arrhenius law: every 10 °C drop doubles life. At rated 75 K rise (115 °C hotspot) design life is 20 000 h. Translate to elevator duty: Light traffic (office, 8 h/day, 5 days/week) – 2 080 h/year → replace ≈ 9 years; inspect every 3 years. Medium traffic (mall, 12 h/day, 7 days/week) – 4 380 h/year → inspect every 2 years, replace ≈ 4.5 years. Heavy traffic (metro, 20 h/day) – 7 300 h/year → inspect every 12 months, replace ≈ 2.5 years. Inspection protocol: • every 6 months – IR scan core; > 95 °C indicates inter-turn short. • annually – megger primary to secondary; < 200 MΩ schedules replacement. • bi-annually – torque check M8 bolts; vibration loosens them, increasing hum and mechanical fatigue.
9. Signs that demand immediate change (even inside cycle limit) • Primary current > 110 % of nameplate at no-load—shorted turns. • Secondary voltage drift > ±5 % despite correct tap—aged winding. • Visible oil or tar around bushings—insulation breakdown. • Audible hammering (loose laminations) > 55 dB(A). • Hot-spot > 110 °C on IR camera.
10. Rapid swap-out (average 15 min) a) Power down, lock-out, megger to confirm dead. b) Photograph leads, label P1-P9. c) Remove 4 bolts, strap old unit out. d) Drop in Nanjing Zhuye transformer, torque 18 N·m. e) Restore leads in exact order, ferrule and torque 0.8 N·m. f) Megger new unit > 500 MΩ before power. g) Power up, repeat no-load and full-load tests. h) Log serial number and date; return old unit for copper recycling.
11. Recycling & sustainability Nanjing Zhuye offers prepaid DHL labels. Cores are annealed and re-stacked, copper windings remelted to 99.9 % purity. One recycled X54DC-04 saves 210 kg CO₂ versus virgin steel and copper—enough to offset the elevator’s standby consumption for two months.