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Ningbo Xinda Elevator Traction Technology Co., Ltd.
GB 7588 2003 eqv EN 81-1: 1998
12 Lift machine
Each lift shall have at least one machine of its own.
12.2 Drive of the car and the counterweight or balancing weight
The calculations of the driving elements shall take into account the possibility of the counterweight or the car resting on its buffers.
12.2.2 Use may be made of belts for coupling the motor or motors to the component on which the electro-mechanical brake (18.104.22.168) operates. In this case a minimum of two belts shall be used.
Devices according to 9.7 shall be provided.
12.4 Braking system
12.4.1 General provisions
b) in the event of the loss of the supply to control circuits.
22.214.171.124 The braking system shall have an electro-mechanical brake (friction type), but may, in addition, have other braking means (e.g. electric).
12.4.2 Electro-mechanical brake
Any solenoid plunger is considered to be a mechanical part, any solenoid coil is not.
126.96.36.199 The component on which the brake operates shall be coupled to the traction sheave or drum or sprocket by direct and positive mechanical means.
188.8.131.52 To hold off the brake, in normal operation, shall require a continuous flow of current.
If, whilst the lift is stationary, one of the contactors has not opened the main contacts, further movement of the car shall be prevented at the latest at the next change in the direction of motion.
184.108.40.206.2 When the motor of the lift is likely to function as a generator, it shall not be possible for the electric device operating the brake to be fed by the driving motor.
NOTE : The use of a diode or capacitor connected directly to the terminals of the brake coil is not considered as a means of delay.
capable of having the brake released by hand and require a constant effort to keep the brake open.
220.127.116.11 Band brakes shall not be used.
18.104.22.168 Brake linings shall be incombustible.
12.5 Emergency operation
12.5.1 If the manual effort required to move the car in the upward direction with its rated load does not exceed 400 N the machine shall be provided with a manual means of emergency operation allowing the car to be moved to a landing with the aid of a smooth, spokeless wheel.
An electric safety device in conformity with 14.1.2 shall be actuated when the wheel is put on the machine at the latest.
22.214.171.124 It shall be possible to check easily from the machine room whether the car is in an unlocking zone. This check may be made, for example, by means of marks on the suspension or governor ropes.
12.5.2 If the effort defined in 12.5.1 is greater than 400 N, a means of emergency electrical operation from the machine room shall be provided in accordance with 126.96.36.199.
The speed of the lift car, half loaded, in downward motion, in mid-travel, excluding all acceleration and retardation periods, shall not exceed the rated speed by more than 5 %, when the supply is at its rated frequency, and the motor voltage is equal to the rated voltage of the equipment 8).
e) docking operation (188.8.131.52 c)).
The stopping of the machine by means of an electric safety device, in conformity with 14.1.2, shall be controlled as detailed below.
The supply shall be interrupted by two independent contactors, the contacts of which shall be in series in the supply circuit. If, whilst the lift is stationary, one of the contactors has not opened the main contacts, further movement of the car shall be prevented at the latest at the next change in the direction of motion.
12.7.2 Drive using a Ward-Leonard system
In cases b) and c) effective precautions shall be taken to prevent the rotation of the motor in the case of a residual field, if any, in the generator (e.g. suicide circuit).
Effective precautions shall be taken to prevent the rotation of the motor in the case of a residual field, if any, in the generator (e.g. suicide circuit).
further movement shall be prevented, at the latest at the next change in direction of motion ;
comparability to 12.7.3.a).
12.8 Monitoring the normal slowdown of the machine in case of reduced buffer stroke
12.8.1 In the case of 10.4.3.2, devices shall check that the slowdown is effective before arrival at terminal landings.
12.8.2 If the slowdown is not effective these devices shall cause the car speed to be reduced in such a way that, if the car or the counterweight comes into contact with the buffers, the striking speed shall not exceed that for which the buffers were designed.
12.8.3 If the device checking the slowdown is not independent of the direction of travel, a device shall check that the movement of the car is in the intended direction.
machine room, breakage of or slack in such a connecting device shall cause the machine to stop through the action of an electric safety device in conformity with 14.1.2.
12.8.5 The control and functioning of these devices shall be so designed that together with the normal speed regulation system there results a slowdown control system complying with the requirements of 14.1.2.
Positive drive lifts shall have a slack rope/chain device actuating an electric safety device in conformity with 14.1.2. This device may be the same as the one required in 9.5.3.
12.10 Motor run time limiter
b) the car/counterweight is stopped in downwards movement by an obstacle which causes the ropes to slip on the traction sheave.
b) time for traveling the full travel, plus 10 s, with a minimum of 20 s if the full travel time is less than 10 s.
12.10.3 The return to normal operation shall only be possible by manual resetting. On restoration of the power after a supply disconnection, maintaining the machine in the stopped position is not necessary.
12.10.4 The motor run time limiter shall not affect the movement of the car under either the inspection operation or the emergency electrical operation.
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