2.5 OVERHEAD MACHINERY SPACE AND MACHINE ROOM INSPECTION
Division 104 of the A17.2 Manual describes the various inspections which are made in the
overhead machinery space and machine room. The beginning of this section describes various
safety precautions that should be followed when making this part of the inspection.
2.5.2 Main Line Switch
The inspector should closely examine the condition of the main line switch before inspecting
any moving part because opening the switch may not have removed all power from a particular
elevator. This condition is very prevalent in group elevator installations. Since 1975, the
ANSI/NFPA-70 National Electrical Code - Rule 620-51 has required a sign be posted on the
switch warning of this condition. The present wording of ANSI/NFPA-70 1984 is as follows:
620-52. Power from More than One Source.
(a) Single and Multi-Car Installations. On single and multi-car installations, equipment
receiving electrical power from more than one source shall be provided with a
disconnecting means from each source of electrical power within sight of the equipment
(b) Warning Sign for Multiple Disconnecting Means. Where multiple disconnecting means
are used and parts of the control panel remain energized from a source other than the one
disconnected, a warning sign shall be mounted on or adjacent to the disconnecting means.
The sign shall be clearly legible and shall read "Warning - Parts of the control panel are
not de-energized by this switch."
(c) Interconnection Multicar Control Panels. Where interconnections between control panels
are necessary for the operation of the system on multicar installations that remain
energized from a source other than the one disconnected, a warning sign in accordance
with Section 620-52(b) shall be mounted on or adjacent to the disconnecting means.
It is mandatory this sign be on all equipment installed after 1975. It is recommended that such
warning signs be placed on all such equipment installed before 1975. It is a constant reminder to
persons working on the equipment that all power is not removed when the switch is open.