General lift door defects

Slow/ fast lift doors

• Causes

Faulty door operator.

Different speed of two doors

• Causes

Door clutch, linkage or catch device roller – any of the parts are worn out, misaligned, thus become faulty.

Banging lift doors

• Causes

1. Tuning problems due to bad installation or careless maintenance.
2. Faulty of rebound device or proximity sensor

Jamb loose, rusty with missing or damaged stopper

• Causes

1. Door components not strong or corrosion resistant
2. Not durable w.r.t usage
3. Vandalism
   e.g. banging on jamb to forcefully open the door

Bulging sill

• Causes

Door unable to withstand rough use or vandalism e.g. banging.

Dirty door sill

• Causes

Inadequate cleaning for elevator will leave the bottom of the door in the window sill to be dirty, where debris and trash are accumulated. This will lead to problem as jammed door

Opening of lobby door when car is not present

• Causes

1. Malfunctioning of car safety shoes – worn out, loose or out of balance due to rusting or careless maintenance.
2. Electro-mechanical interlock installed on the lobby door is not synchronized with car door or has become faulty with time.

Opening of car door in unlocking zone

• Causes

1. Faulty micro-switch due to mishandling during maintenance.
2. Constant hitting or banging on door to open it forcefully damages the micro-switch.