Is Separate earthing required for Lifts. Why
The function of the earthing system in an electrical installation is to dissipate in the ground the current intensities of any nature that may originate, whether from fault currents, at an industrial frequency or due to atmospheric discharges.
Earthing has two main functions: to ensure the safety of people and the electrical appliances connected to it. Earthing provides a path for electrical current to flow safely to the ground in the event of a system fault or overload, reducing the risk of fire, electrocution, and damage to equipment.
In addition, effective earthing ensures that the voltage in the system is stable and remains within safe limits. This is especially important in systems with sensitive equipment that voltage fluctuations can easily damage.
A passenger lift is essentially a small, metal box with limited airflow, suspended many meters in the air by nothing more than a hoist.
All metal parts of the lift that may become live due to insulation failure are subject to grounding: the enclosures of all electrical appliances, the guiding cabins, the cab, the shaft doors, the shield enclosures, the support frame, the motor housing, the brake magnet housing, transformers, lamp housing, etc. Lift comprises of Motors and VFD drives. No matter how good the VFD cable, motors on drives still need reliable shaft grounding.
The above indicated that earthing is to be provided but no code requirement to have dedicated earthing. But to achieve a resistance valve of 1 ohm, it is preferred to have an earth pit but the same can be dedicated, all lifts combined to 2 looped earth pits to achieve the resistance.