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Component · Safety critical

Safety Devices

The components that exist for one bad day. We supply these as genuine parts only, and we will not price-match a copy — the failure mode of a counterfeit governor is not a warranty claim.

Device types

Four independent devices, each able to stop the car alone.

None of these substitute for another. A lift is only as safe as the weakest one in the chain.

Overspeed

Governor

Spins with the car and trips the safety gear if speed exceeds roughly 115 per cent of rated. The device that starts the emergency stop sequence.

Trip speed: rated + 15% typical
Type: Uni- or bi-directional
Testing: Annual, recorded
Location: Machine room

Best for: The first device to detect a runaway condition, before anything else reacts.
Trade-off: Only useful if actually trip-tested — an untested governor is unproven.

Mechanical Elevator safety gear wedges mounted under the car sling

Safety gear

Wedges under the sling that clamp the guide rails when the governor calls for it. Instantaneous below about 1 m/s, progressive above it.

Type: Instantaneous or progressive
Trigger: Governor rope pull
Grip: Guide rail
Speed limit: 1 m/s split point

Best for: A purely mechanical last resort that needs no power to work.
Trade-off: A trip leaves marks on the rail that must be inspected, not just cleaned off.

Pit

Buffers

Spring or oil units at the bottom of the pit. The absolute last line of defence, sized to decelerate a fully loaded car without injury.

Type: Spring or oil
Location: Pit, under car + counterweight
Stroke: Set by rated speed
Testing: Visual + compression check

Best for: Passive protection that requires no signal or power to function.
Trade-off: A leaking oil buffer has lost most of its stopping capacity silently.

Doors

Elevator door interlock being tested by a safety inspection engineer

Interlocks

Mechanical and electrical locks on every landing door. The car cannot move unless every single one reports locked, on every floor.

Type: Mechanical + electrical
Location: Every landing door
Fail state: Car cannot run
Testing: Every service visit

Best for: The device that most directly prevents a fall into an open shaft.
Trade-off: A single faulty interlock is a serious finding, not a maintenance note.

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What it does

Independent systems, each able to stop the car alone.

Lift safety is a chain of separate devices rather than one mechanism. The governor watches speed, the safety gear grips the rails, the interlocks watch the doors and the buffers absorb the last of it. Any one of them acting is enough.

Specification

What we supply.

Progressive safety gear is required above about 1 m/s because instantaneous gear decelerates too abruptly at speed. Below that, instantaneous gear is normal practice.

Elevator safety devices including overspeed governor and safety gear

Genuine parts, no exceptions This is the one category where we will lose the order rather than match a cheaper price with an uncertified copy.

Overspeed governor Bi-directional available

Trip speed rated + 15 %typical

Safety gear Instantaneous or progressive

Buffers Spring or oil

Door interlocks Mechanical + electrical

ARD Battery rescue deviceoptional

Certification Supplied with test data

When to replace

When safety components need attention.

These parts are designed to be tested. A governor that has not tripped in ten years is not proven — it is untested.

Testing

No record of a governor trip test

The most common finding when we take over a contract. It should be tested and recorded annually.

Evidence

Safety gear marks on the rails

The lift has tripped at some point. That needs inspecting and recording rather than cleaning off.

Doors

Any interlock not holding

A car that can move with a landing door unlocked is a serious fault. Take the lift out of service.

Age

Buffers compressed or oil buffers leaking

Buffers are the last line of defence. A leaking oil buffer has lost most of its capacity.

Ordering

What we need to quote this part.

Photographs of the nameplate save days. Most delays come from identifying the wrong variant, not from supply.

Governor nameplate. Make, model and rated trip speed, photographed.
Rated speed and load. Determines whether instantaneous or progressive safety gear applies.
Rail profile. Safety gear must match the rail section it grips.
Travel height and pit depth. Used to select buffer type and stroke.

Common questions

Before you order

What is the price of an ARD (automatic rescue device)?

ARD price depends on car capacity and whether it is a battery or capacitor-based unit. It is quoted alongside the controller, since the rescue device has to talk to the drive electronics. We also supply the smaller safety-circuit parts — limit switches, buffer springs, junction boxes and governor encoders — individually where only one component needs replacing.

Can we buy a cheaper equivalent?

Not from us. Safety components are the one category where we will lose the order rather than supply an uncertified copy, because the failure mode is somebody getting hurt.

How often should safety devices be tested?

Annually, as part of a safety inspection, with the actual readings recorded rather than a certificate ticked.

What is an ARD and do we need one?

An automatic rescue device brings the car to the nearest landing and opens the doors on power failure. In a residential building it usually pays for itself in avoided entrapments.

Instantaneous or progressive safety gear?

Progressive above about 1 m/s, because instantaneous gear decelerates too abruptly at speed. Below that, instantaneous is normal.

Also supplied

Other components we stock and fit.

Supplied for lifts we maintain and for lifts we do not.

Control Panels

VVVF drives and controllers. The part that most often decides whether an old lift is worth keeping.

Open

COP & LOP Panels

Car and landing fixtures, including braille and lower-reach accessible sets.

Open

Elevator Doors

Automatic, collapsible and vertical bi-parting door sets with their operators.

Open

Elevator Cabin

Car interiors in stainless, glass, stone and timber, with lighting and flooring.

Open

Guide Rails

Machined T-section rails and brackets. Ride quality is mostly a rail alignment problem.

Open

Safety Devices

Governors, safety gear, buffers and interlocks — the parts that are never optional.

Open

Traction Machine

Geared and gearless machines with brakes, rated against starts per hour.

Open

When was the governor last tripped?

If nobody in the building can answer that, book an inspection. These are the parts that only matter once, and only if they work.

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