MN Elevator Mechanic cheat sheet

ASME A17.1/CSA B44 is the new-installation safety code; A17.1s is its supplement of addenda and is adopted as part of the code edition it supplements.

A17.2 covers inspection and testing of existing elevators and escalators; A17.3 covers existing elevator and escalator upgrades; A17.4 covers emergency evacuation of passengers from stalled cars.

A17.5 governs elevator and escalator electrical equipment; A17.6 governs suspension means (wire rope, coated steel belt, and similar) and their terminations and inspection criteria.

A18.1 covers platform lifts and stairway chairlifts; it is a separate standard from A17.1 and applies to accessibility lifts not within A17.1 scope.

A17.1 Rule 2.26 requires a Type A (car) and Type B (hoistway) safety test: safety applies at 125% of rated load at rated speed for the governor-tripped safety.

Governor tripping speed for a car safety is set between 115% and 140% of rated speed for speeds up to 600 ft/min; higher speeds use a lower upper limit per the code table.

A17.1 requires a machine-room (or control-space) access door to be self-closing and self-locking, openable from the inside without a key, and at least 29.5 in by 6 ft 8 in clear.

Pit access: a pit ladder is required where pit depth exceeds 3 ft, and the ladder must be accessible from the lowest landing door sill or a pit access door.

Geared traction machines use a worm gear to transmit power and provide holding; gearless machines couple the sheave directly to the motor and are used for higher speeds.

A traction elevator relies on friction between hoist ropes and the drive sheave; the counterweight is typically sized to balance car weight plus about 40-50% of rated load.

The car safety is set by a governor; a rope-grip governor grips the governor rope to pull the safety, while a car-mounted overspeed device may trip mechanically.

A roller-type safety grips the guide rails progressively; a wedge-type safety is instant in action and is used at lower speeds.

Rope data: 1/2 in diameter 6x19 or 8x19 traction rope is common; ropes must be replaced when broken wires, wear, or corrosion exceed A17.6/A17.1 criteria.

A brake on a traction machine must be capable of holding 125% of rated load; it is spring-applied and electrically released (fail-safe).

The counterweight must have a guard or be enclosed where it can be struck, and counterweight safeties are required on some installations per A17.1.

Door operators: a car door must have a door-closed switch and a door-zone/leveling switch; the door operator must close against a force limit to protect passengers.

Hydraulic elevators use a power unit (pump, motor, valve) to pressurize oil that pushes a plunger in a cylinder; movement is by fluid displacement, not traction.

In-ground (holeless) cylinders are buried in the ground; holeless/jack configurations use above-ground cylinders and are common where drilling is restricted.

The lowering valve controls descent by metering oil back to the tank; a ruptured-valve or pipe-break valve limits downward speed if the line breaks.

A hydraulic elevator requires a pressure-relief valve set to open at no more than 125% of the design pressure, protecting the system from overpressure.

The oil tank must have a vent, and the tank oil level must be maintained; low oil can cause the pump to cavitate and the car to settle.

Hydraulic elevators are limited in travel and speed; typical maximum travel is about 60 ft with speeds up to about 200 ft/min for conventional systems.

The cylinder must have a means to detect and stop the car if the oil level in the tank drops, and the system must be protected against overtravel.

Hydraulic elevators require a check valve to hold the car and a separate lowering valve; the valve must be accessible for maintenance.

Elevator power supply must be a dedicated circuit; the main line disconnect must be lockable and located where it is accessible to maintenance personnel.

The main line disconnect must be capable of being locked in the open position, and a means must be provided to identify the disconnect and its circuit.

Control circuits commonly operate at 120 V AC or 24 V DC; the code requires the control circuit to be protected against overcurrent.

The machine room must have lighting of at least 10 ft-candles at the floor, and a grounded receptacle must be provided in the machine room and pit.

Grounding: the elevator equipment must be bonded to the building grounding electrode system; the equipment grounding conductor must be sized per the NEC.

A phase-reversal or phase-failure relay protects the motor from incorrect phase sequence or loss of a phase on three-phase power.

The car must have a light and a two-way communication means (phone or intercom) that works without the building power, typically battery-backed.

A ground-fault circuit interrupter is required for pit receptacles and other wet-location receptacles per the NEC and A17.1.

A17.2 requires periodic inspection and testing; the interval is set by the authority having jurisdiction, and Minnesota requires annual inspections for elevators.

The Category 1 test is the routine annual test; Category 5 is the full-load safety test performed every 5 years.

The no-load safety test verifies governor trip and safety set; the full-load test verifies the safety holds 125% of rated load.

The oil level, rope condition, brake wear, door operation, and safety devices should be checked on each maintenance visit.

A maintenance record must be kept and made available to the inspector; records document tests, repairs, and code compliance.

The pit should be checked for water, debris, and proper lighting; the pit ladder and stop switch must be functional.

Escalator maintenance includes step/skirt clearance, handrail speed, comb plate condition, and brake test; the brake must stop a loaded escalator within the code distance.

The governor should be tested for tripping speed and the safety for setting; the test tag or record must be updated after each test.

Lockout/tagout: the main disconnect must be locked open and tagged before working on or near electrical components; verify zero energy before touching conductors.

Before entering the pit or car top, place the car on inspection operation and verify the stop switch works; never rely on the door interlock alone.

Car-top work requires a top-of-car inspection station with a stop switch, and the car top must have a guardrail where required by A17.1.

Fall protection: use a body harness and lanyard when working on the car top or near an open hoistway, and never stand on the car crosshead.

Barricade the hoistway opening and post warning signs when a landing door is open or removed; never leave an open hoistway unattended.

Use proper lifting technique and equipment for heavy components; never stand under a suspended load or under the car.

Emergency evacuation must follow A17.4 procedures; only trained personnel should move passengers from a stalled car.

Personal protective equipment: hard hat, safety glasses, gloves, and safety shoes are required on the job site; hearing protection is required near loud machinery.

Minnesota elevator regulation is administered by the Minnesota Department of Labor and Industry (DLI); the Elevator Safety Code is in Minnesota Rules Chapter 1307.

Minnesota adopts ASME A17.1 and related A17 standards by reference in its rules, with amendments published in the state rule chapter.

Elevator mechanics in Minnesota must be licensed; the license is issued by DLI and requires passing an examination and meeting experience requirements.

A permit is required before installing or altering an elevator; the installation must be inspected by a DLI inspector or approved inspector before use.

Minnesota requires periodic inspections, and the owner must maintain a current certificate of inspection posted in the elevator or machine room.

The mechanic license must be renewed; continuing education and code-update training may be required for renewal.

Report accidents and serious injuries to DLI; the department may investigate and require corrective action.

Work on elevators must be performed by licensed personnel or under the direct supervision of a licensed mechanic, per state law.

Escalator code requirements are in ASME A17.1; escalators must have a brake that stops a loaded step band within the code stopping distance.

The comb plate, step/skirt clearance, and handrail speed are key inspection points; handrail speed should match step speed within tolerance.

Escalators require a stop switch at the top and bottom landings, and the emergency stop button must be clearly marked.

Moving walks are covered by A17.1; the pallet/skirt clearance and handrail/balustrade requirements are similar to escalators.

A18.1 platform lifts and stairway chairlifts require a clear landing, a continuous run, and a means to prevent operation outside the intended path.

Accessibility lifts must have a means for the user to call for help and must meet the A18.1 requirements for capacity, speed, and guarding.

Escalator steps must be checked for missing or broken treads and the step chain for wear; the skirt guard must be intact.

A18.1 requires the lift to be inspected and tested; the inspection interval is set by the AHJ and must be documented.