The isolating switch in the elevator machine room or main control panel that disconnects the elevator from the mains electrical supply, enabling safe maintenance and emergency isolation of all elevator circuits.
Full Definition
The main switch (also called the main isolator or main disconnecting means) is required by EN 81-20 in every elevator installation. Its functions: (1) Isolation — manually operated switch that disconnects all elevator circuits from the mains power supply except the machine room lighting, socket outlet, and emergency alarm circuit, which must remain live; (2) Position — located in the machine room at the main control panel, or in the controller enclosure for MRL elevators; it must be within reach of the authorised technician without crossing moving parts; (3) Type — must be a lockable device (padlockable in the open/off position) to allow maintenance personnel to safely lock out the power before working on the equipment (lockout-tagout, LOTO); (4) Rating — must be rated for the full motor starting current; (5) Phase indication — the supply phase sequence indicator may be incorporated; (6) For hydraulic elevators a separate oil pump isolator is required. EN 81-20 Section 13 specifies that: the main switch must not interrupt the lighting circuit inside the car, the pit lighting, or the emergency alarm power. In modern MRL elevators, the main switch is typically located in a locked controller enclosure at a landing, with a key switch enabling access.
