The main components
A traction lift has a car and a counterweight suspended by steel ropes or belts that pass over a sheave driven by the machine. The counterweight balances the car plus roughly half the rated load, so the motor only has to move the difference. This is the drive arrangement in most modern commercial passenger lifts and in the majority of block-of-flats installations.
Fixed to the shaft are the guide rails that keep the car and counterweight travelling true. At the bottom of the shaft sit the buffers — energy absorbers of last resort if the car ever overtravels. Wear or contamination on any of these components tends to surface as one of the symptoms covered in the troubleshooting index long before it becomes a safety event.
What happens when you press a button
A landing call registers with the controller, which selects a car using its dispatch algorithm and books the stop into that car's queue. If a lift ever stops responding at the landing button, that is the out-of-service pattern — the controller has either dropped the call or taken the car out of service on a fault.
The car levels at the floor, the door operator opens the car doors, and the landing doors follow because they are mechanically coupled via a clutch on the car door. Two common faults from this stage — the lift stopping short of the landing sill and the doors reopening every time they try to close — are documented in levelling problems and doors that keep reopening.
Where to go next
Two shortcuts from this reference: symptom pages for the faults it touches on, and long-form guides for the paperwork and buying decisions behind it.
Jump to symptoms
Fault-first walkthroughs — start here if something isn't working.
Read the guide
Longer editorial covering the duties, costs and buying steps behind this reference.
Frequently asked questions
- Do all lifts have a machine room?
- No. Machine-room-less (MRL) lifts locate the motor and controller inside the shaft, usually at the top. Older traction lifts and most hydraulic lifts still use a separate machine room.
- How is the counterweight sized?
- Typically at car weight plus about 50 per cent of the rated load, so the motor is balanced through most of the duty cycle.