The Commissioner may permit the temporary use of any
conveyance during its installation or construction, prior to certification
for use by the general public, upon compliance with such conditions
as the Commissioner may impose. A notice bearing the information that
the equipment has not been finally approved shall be conspicuously
posted on, near or visible from each entry to such device. In the
case of elevators, such permission shall not be granted until the
elevator shall have been tested with the rated load and the car safety
and the terminal stopping equipment have been tested to determine
their safety and until either permanent or temporary guards or enclosures
are placed on the car and around the hoistway and at the landing entrances
on each floor. Landing entrance guards shall be provided with locks
that can be released from the hoistway side only. Automatic and continuous
pressure elevators shall not be placed in temporary operation by the
use of landing push buttons unless door-locking devices and/or interlocks
are installed and in operation.