Electrical wiring and switchgear

• Pages: 89-90

B9 Electrical wiring and switchgear

B9.1. General

B9.l.l. In view of its importance from the point of view of

safety, electrical wiring associated with lifts should be designed

and installed with the utmost care. The wiring should be in

conformity with the rules in force in the country where the lift is

installed.

B9.l.2. Every precaution should be taken to prevent incidents

and accidents that could result from accidental contact with con-

ductors or from insulation faults to earth or between conductors.

In particular, one or more insulation faults to earth should neither

cause the lift to start nor render the safety devices ineffective.

B9.2. Protection of motors

B9.2.l. Lift motors should be protected against overloading

and short circuits.

B9.2.2. Every measure should be taken to prevent damage

to equipment in case of failure of a single phase of the electricity

supply.

B9.3. Contactors and relays

B9.3.1. In view of the fundamental role which contactors and

relays play with regard to safety, such equipment should be

selected with the utmost care. It should be of sound design and

construction, and its specifications should correspond to the oper-

ating conditions.

B9.4. Voltage for control and safety circuits

B9.4.l. The r.m.s. voltage between conductors in controland

safety circuits should not exceed 250 volts.

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