Why install a Counterweight Displacement Detector?
Current New Zealand codes require all conventional traction lifts which travel 15 Metres or more to be fitted with a Counterweight Displacement Detector. This device senses displacement of the counterweight from its normal location and is designed to eliminate the risk of the lift car and counterweight coming into contact with each other. Such an event occurring while the lift is travelling at speed could have potentially serious consequences.
A small number of lifts without Displacement Detectors installed were found to be running after the Canterbury earthquake and subsequent after-shocks posing significant risk to the equipment, and more importantly, to passengers. Lifts of various lengths of travel were affected; many of which only served two floors.
One less publicised result of the earthquakes was the extent of damage to services within buildings that outwardly may have appeared largely unaffected by the events. A significant number of elevators installed in the area impacted by the seismic activity were damaged and while the buildings themselves were fit for occupation within a short time-frame, remedial works to the elevators delayed their return to service and impaired normal building use.
Many lifts in the Christchurch area are fitted with a Counterweight Displacement Detectors and the successful activation of the device undoubtedly reduced the level of equipment damage and injuries.
Summary of benefits:
• Increased protection for lift users during seismic activity
• Peace of mind for building owners and tenants
• Reduced risk of injury
• Reduced risk of significant equipment failure
• Cost effective
• Quick installation
• Minimal downtime
• Compatible with most lift control systems
• Fully automatic