Pennsylvania Code › Title 34 - LABOR AND INDUSTRY › Part I - Department of Labor and Industry › Chapter 7 - ELEVATORS, LIFTS, ESCALATORS, DUMBWAITERS, HOISTS ANDTRAMWAYS › Subchapter I - FREIGHT ELEVATORS › SPECIAL REQUIREMENTS › Section 7.292 - Electric freight elevators

Current through Register Vol. 54, No. 28, July 13, 2024
(a) All
					 electric freight elevators operated by polyphase alternating current motors
					 shall be provided with relays of the potential type, or other approved devices,
					 which will prevent the starting of the motor if the phase rotation is in the
					 wrong direction, or if there is a failure in any phase.
(b) No potential differences in excess of 250
					 volts shall be used in connection with the car switch or automatic control
					 circuits of new electric freight elevators. When direct current is the only
					 available source of power and it is impracticable to keep within this
					 requirement, application may be made to the Department for special permission
					 to use a higher voltage. Full information shall be given with each application
					 for a special permit. When step-down transformers are used in connection with
					 an alternating current car switch and automatic control circuits, they shall be
					 of the two-winding type.
(c) When
					 the operating apparatus of an existing electric freight elevator has a
					 potential difference in excess of 250 volts, the hand control ropes or cables
					 shall be provided with insulating balls, placed to prevent elevator operators
					 from receiving electric shocks.
(d)
					 An emergency stop switch shall be installed in every new electric elevator car
					 when the hoisting machine is equipped with an electric brake. Such a switch
					 shall operate to open a main line switch independent of the car-controlling
					 circuit wiring. An emergency switch shall be installed in each existing
					 electric elevator car when the hoisting machine is equipped with an electric
					 brake and shall operate to open a main line switch independent of the
					 car-controlling circuit wiring.
(e)
					 In all installations where the power for elevator control switches is dependent
					 upon main line circuit breakers, potential switches or other similar electric
					 apparatus, connections shall be made so that the operation of any fire alarm
					 system connected to such main line circuit breakers, potential switches or
					 other similar electric apparatus, will not cut off the power to the elevator
					 control circuit.
(f) The machine
					 controllers of all electric freight elevators shall be equipped with a
					 potential switch of either the manual or power-closing type, so designed that
					 when the current is interrupted from any cause whatever it will automatically
					 apply the brake and stop the elevator car.
(g) Switches shall be provided in connection
					 with new electric freight elevators so that the motor control circuit and the
					 brake control circuit are opened before or at the time the governor trips.
					 Switches shall be provided in existing electric freight elevators so that the
					 motor control circuit and the brake control circuit are opened before or at the
					 time the governor trips or when the safety operates.
This section cited in 34 Pa. Code §
													7.283 (relating to safety
						  requirements); 34 Pa. Code §
													7.291 (relating to general); and
						  34 Pa Code §
													7.296 (relating to belted and
						  silent chain drive elevators).