NEIEP Mechanic Exam cheat sheet

Plumb the guide rails before setting the car or counterweight frame: rail alignment (plumb, gauge, and twist) is set to the manufacturer's tolerances, typically checked with a plumb line or laser over the full hoistway height, because rail misalignment transfers directly into ride quality and guide-shoe wear.

Rail brackets are shimmed and grouted to the hoistway wall; concrete-embedded or welded brackets must be installed per the approved layout drawing, and rail joint plates are staggered so no two adjacent rail joints align on the same bracket.

Set the machine beam and sheave so the ropes fall plumb to the car and counterweight hitches; sheave alignment is checked with a straightedge and feeler gauge to prevent rope fleet-angle error and uneven rope loading.

Counterweight weight is calculated as car weight plus approximately 40-50% of rated load (commonly 45%), and the counterweight must be blocked and secured before ropes are installed or removed.

Rope equalization (tensioning) is done with a dynamometer or by the deflection method after the car is loaded; unequal rope tension causes individual rope overload and premature wear.

Door operator installation requires the car door and landing door interlocks to be set so the doors cannot open unless the car is at that landing and within the unlocking zone (typically 18 in. / 450 mm above or below landing level).

Escalator installation sequence: truss set and aligned on the support beams, then step chain and steps, then balustrade and handrail, then drive and brake, then controller; step-to-skirt and step-to-comb clearances are set only after the truss is fully loaded and level.

Before turnover, run the conveyance at rated speed and rated load, verify the brake stops and holds the load, and document the as-built clearances (top/bottom car clearance, refuge space, pit depth) against the code-required minimums.

Planned maintenance intervals are driven by usage (starts per hour, trips per day) and manufacturer instructions; a typical traction elevator PM covers ropes, sheave and rope groove wear, guide shoes, door operation, brake, governor, and safeties.

Rope retirement criteria follow the manufacturer's broken-wire count over a specified lay length, plus diameter reduction, corrosion, and valley breaks; rope wear is measured with a go/no-go gauge and recorded.

Brake maintenance: check lining thickness, drum/disk condition, spring set, and coil gap; the brake must stop and hold the car at rated load, and a dragging brake shows as heat, noise, and leveling drift.

Governor and safety test: trip the governor at its set speed, confirm the safety applies and grips the rail, and verify the governor rope and tension sheave are free; record the test.

Door system PM: clean and lubricate the door track, check the door closer/operator belt tension, verify the interlock and gate switch make and break correctly, and confirm the door reopen device reverses on obstruction.

Escalator PM: check step chain elongation and tension, step-to-skirt clearance, comb segment condition, handrail speed versus step speed (handrail should be within 0 to +2% of step speed), brake setting, and the missing-step and handrail-speed monitoring devices.

Hydraulic elevator PM: check oil level and condition, packing and seal leakage, valve operation, and the rupture valve/pipe check; the tank breather must be clear and the oil temperature within the manufacturer's range.

Troubleshooting rule: verify the simple causes first (power, fuses, door lock circuit, limit switches, safety circuit continuity) before replacing boards or motors; a safety-circuit open will prevent the car from running in either direction.

Ohm's law: V = I x R; power: P = V x I = I²R = V²/R. In a series circuit, current is common and voltage divides; in parallel, voltage is common and current divides.

Three-phase power: P = √3 x V(line) x I(line) x power factor. Motor slip = (synchronous speed − rotor speed)/synchronous speed; synchronous speed = 120 x frequency / number of poles.

Motor torque is proportional to current in a DC machine and to the square of voltage in an AC induction machine at constant frequency; a reduced-voltage start reduces starting torque by the square of the voltage ratio.

A VVVF (variable voltage variable frequency) drive controls an induction motor by varying frequency to set speed and voltage to hold flux; the encoder or resolver provides speed/position feedback for closed-loop control.

Contactors and relays: the coil is the control element, the contacts are the power or logic element; a normally closed (NC) contact opens when the coil energizes. Interlocks prevent opposing contactors from closing simultaneously.

Safety chain (series safety circuit) is wired so that any opened switch (governor, pit, top-of-car, final limits, door locks) removes power from the driving machine; it is a fail-safe series loop.

Mechanical advantage of a rope system: a 2:1 (rope) roping doubles the load on the rope and halves the car travel relative to rope travel; the counterweight is sized to balance the car plus a fraction of rated load.

Braking: friction torque = coefficient of friction x normal force x effective radius; brake capacity must exceed the static load torque at rated load plus a margin, and holding is verified by the brake test.

Lockout/tagout (LOTO): isolate and lock the mainline disconnect, verify zero energy with a meter, and tag; only the person who applied the lock removes it.

Never work on a car top or in the pit without the car secured: set the car on its own safeties or block it, and use the top-of-car inspection station with the stop switch in reach.

Pit and hoistway entry: stop the car at a landing, open the door with the door-zone key, place the car on inspection, and use a pit ladder and the pit stop switch; never ride the car top across the overhead.

Personal protective equipment: hard hat, safety glasses, gloves, and fall protection (full-body harness with lanyard to an anchor) when working at height or on a car top without a guardrail.

The ASME A17.1/CSA B44 Safety Code for Elevators and Escalators and ASME A17.3 for existing elevators define the required clearances, safety devices, and inspection/testing intervals; local AHJ rules may be stricter.

Electrical safe work: treat all circuits as energized until tested; use a CAT-rated meter, keep one hand free, and never bypass a safety device or fuse with a jumper except for a documented, supervised test.

Confined space and hoistway hazards: test for oxygen and combustibles where applicable, keep the pit clear of water and debris, and guard all open hoistway and floor openings with a barricade.

Report and document: record all code-required tests (safety, governor, brake, door) and any defects; an unsafe condition is taken out of service and tagged until corrected.