820 - Hydraulic Elevator Maintenance

Why are frequent inspections of line starter contactors necessary?

• Thermal overloads require constant care

• High current causes contact arcing

• High insulation failure rate

• To maintain single phasing

During hydraulic pump motor starting, which of the following is true?

• Oil immediately flows to the jack

• Line current gradually builds

• Pressure is not regulated

• Line current is high

In order to take advantage of Wye-Delta starting for a pump unit, what is required?

• Two line starters

• A two speed motor

• An overload contactor

• A faster style contactor

Why is it important to only operate line starters with their covers in the proper location?

• To prevent flashover between contacts

• To prevent arc shields from shorting contacts

• To lower operating noise to a minimum

• To hold contacts in proper alignment

What is the operation quality of a soft starter converter that prevents voltage sags and dimming of lights in a building often associated with hydraulic pump starting?

• DC conversion allows smooth starting

• Starting current is maintained at a preset rate

• Single phase, two phase and three phase transition

• Lower belt slippage under heavy starting conditions

What is a special requirement for hydraulic elevator systems that use flexible line installed in high pressure portions of the system?

• Monthly inspection

• Five year testing

• Replacement at six-year intervals

• Annual disassembly and inspection

Of the following items, which has the greatest effect on the leveling accuracy of a hydraulic elevator?

• Line voltage fluctuation

• Condition of line starter contacts

• Oil type and condition

• Oil temperature

Which of the following statements best describes a proper maintenance operation for hydraulic pump belts?

• If cracks appear in a pump belt it should be replaced with a new one

• Check belt tension by applying 50 lbs pressure and observing less than 1/8 inch deflection per inch of span

• Belt alignment is accomplished by observing belt tracking in sheaves and aligning for center

• A downward force with one finger should deflect a belt about 1/64 of an inch per inch of belt span

Which of the following items is NOT a maintenance procedure required for a hydraulic elevator installation?

• Inspect isolation pads on the machine room floor. Replace worn isolation pads to minimize structural borne noise.

• Inspect pipe couplings and unions for oil leaks. Check hardware for tightness when cut or rolled groove pipe joints are used.

• Inspect pipe supports and hangers for proper noise isolation material. They should bear the weight of the pipe to relieve stress on the fittings.

• Be certain the port to atmosphere is not plugged and drain and refill if water is suspected.

Which of the following statements is correct about hydraulic oil used for elevators?

• The viscosity is mineral based hydraulic fluid does not change with temperature.

• Oil temperature should remain below 100 degrees F for proper operation.

• Oil temperature stabilization is important for leveling accuracy.

• Submersible electric heaters in elevator hydraulic tanks are not permitted.