MD Elevator Mechanic flashcards
MD Elevator Mechanic · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- ASME A17.1 scope
- The model safety code for new elevators, escalators, dumbwaiters, and moving walks. Maryland adopts it by reference, so its design, construction, and test requirements are enforceable.
- ASME A17.3 purpose
- The code for existing elevators and escalators. It sets retroactive safety requirements for installations built before current A17.1 editions, covering items like door restrictors and pit ladders.
- Category 1 test
- A periodic inspection and test performed at the interval set by the jurisdiction, typically annually. It covers items such as door operation, emergency communication, and normal stopping accuracy.
- Category 5 test
- A full periodic test performed every five years. On traction elevators it includes the safety (governor-tripped), buffer, and full-load brake tests, plus rated-load speed checks.
- Governor trip speed range
- The governor must trip at 115% to 140% of rated car speed. Tripping below 115% risks nuisance stops; above 140% the safety may not set before the car overspeeds.
- Oil buffer return time
- After compression during a test, an oil buffer plunger must return to its normal position within 90 seconds. Slow return indicates low oil, a bent plunger, or a clogged orifice.
- Door kinetic energy limit
- Closing door kinetic energy is limited to about 3.5 ft-lbf average and 7 ft-lbf peak. The force gauge measures at the midpoint and the last 2 inches of travel.
- Firefighters Phase I recall
- On activation of a lobby smoke detector or key switch, cars return nonstop to the designated landing, open doors, and park with doors open, disabling normal car calls.
- Escalator handrail speed tolerance
- Handrail speed must be within 0 to +2% of step speed. A handrail running slower than the steps causes passengers to lose balance and must be corrected.
- Top-of-car refuge space
- Code requires a clear refuge space above the car and below the pit floor sized to rated speed. It protects a mechanic from being crushed against the overhead structure.
- Roping factor 2:1
- With 2:1 roping, the rope travels twice the car distance, so car speed is half the rope speed. The counterweight and sheave loads are also reduced compared with 1:1.
- Counterweight balance point
- The counterweight equals car weight plus roughly 40-50% of rated load. This balance minimizes motor torque and brake duty over the normal load range.
- Gearless traction machine
- A direct-drive machine with the sheave mounted on the motor shaft. It avoids worm-gear losses and is used for high-speed and high-rise traction elevators.
- Hydraulic relief valve setting
- The relief valve must be set between 150% and 200% of full-load pressure and must not exceed the jack or cylinder pressure rating. It protects against overpressure.
- Elevator safety device
- A car-mounted clamping mechanism that grips the guide rails when the governor trips. It must stop and hold the car with rated load without permanent deformation of rails.
- VVVF drive function
- A variable-voltage variable-frequency inverter controls motor speed and torque by adjusting voltage and frequency. It provides smooth acceleration and regenerative or dynamic braking.
- Escalator auxiliary brake
- A second brake on the drive shaft, required on newer escalators. It stops the unit if the main brake or drive chain fails, preventing a free-fall of loaded steps.
- Motor nameplate FLA
- Full-load amperes on the motor nameplate set the branch circuit and disconnect sizing. Conductors and overloads are selected from this value, not from the controller rating.
- Mainline disconnect location
- The main power disconnect must be within sight of the controller and capable of being locked open. It is the energy-isolation point for maintenance and repair.
- Lockout/tagout sequence
- Open the mainline disconnect, apply a personal lock and tag, then verify zero energy with a meter at the controller terminals before touching conductors or moving parts.
- Car-top inspection speed
- Inspection operation limits car speed to about 150 feet per minute. The car-top station must have an accessible stop switch and a functioning inspection light.
- Safe pit entry procedure
- Bring the car to the top landing, turn on the pit light, open the pit stop switch, and verify the car cannot move. Never enter a pit under an unblocked car.
- Hydraulic car blocking
- Before working under a hydraulic car, set it on its safeties or on pipe stands. The power unit valve is not a positive hold and can leak down under load.
- Machine room housekeeping
- Machine rooms must be kept clear of stored combustibles and maintained at the temperature range the controller requires. Sprinklers, if present, need a shunt trip.
- Rope broken-wire criteria
- Suspension ropes are replaced when broken wires within a specified lay length exceed the A17.1 table, or when diameter loss and corrosion exceed limits.
- Escalator comb inspection
- Check for missing or broken comb teeth, correct step-to-skirt clearance, and debris in the comb pan. Defects here cause the most common escalator passenger injuries.
- Manual lowering valve use
- For a hydraulic entrapment, open the manual lowering valve slowly to bring the car to a landing. Confirm passenger communication and door position before moving.
- Maryland licensing authority
- Elevator mechanics and contractors are licensed by the Maryland Department of Labor, Division of Occupational and Professional Licensing, Elevator Safety unit.
- Apprentice supervision rule
- An unlicensed apprentice may perform elevator work only under direct supervision of a licensed mechanic. Independent work by an apprentice violates Maryland licensing law.
- Permit before alteration
- A permit from the local jurisdiction or the State is required before installing or altering a conveyance. Work without a permit can be ordered removed and penalized.
- Continuing education renewal
- Maryland requires continuing education credits each renewal cycle, including code-update content. Failure to complete credits blocks license renewal until satisfied.
- Reportable accident duty
- Accidents causing injury or entrapment must be reported to the Division within its regulatory timeframe. The unit may be locked out pending investigation.