Montgomery County                           2837

680-4. Lighting.

(a)    The provisions of this Section apply to lighting fixtures
installed below the pool surface.

(b)    No lighting fixture shall be installed for operation at more
than 12 volts between conductors.

(c)    Lighting fixtures mounted in walls shall be installed with
the top of the fixture lens at least 18 inches below the normal water
level of the pool. A lighting fixture facing upward shall have the lens
adequately guarded to prevent contact by any person.

(d)    All exposed noncurrent-carrying metal parts of lighting
fixtures shall be grounded. The fixture shall be secured and grounded
to the forming shell by a positive locking device which will assure a
low resistance contact and which will require a tool to remove the
fixture from the forming shell. Definition. A "forming shell" is a
metal housing designed to contain a lighting fixture assembly for
mounting into a swimming pool structure. The forming shell pro-
vides a bond between the raceway and the noncurrent-carrying metal
parts of the fixture.

(e)     Fixtures approved for the purpose may be installed outside
the walls of the pool in closed recesses which are adequately drained
and accessible for maintenance.

(f)    Approved metal forming shells shall be installed for the
mounting of all wet niche underwater fixtures and shall be equipped
with provisions for threaded conduit entries. A rigid conduit of brass
or other approved corrosion-resistant metal shall extend from the
forming shell to a suitable junction box located as provided in Section
680-5. Metal parts of the fixture and forming shell in contact with
the pool water shall be of brass or other approved corrosion-resistant
metal.

(g)    Underwater lighting fixtures supplied either directly from
a branch circuit or by a transformer meeting the requirements of
Section 680-4 (h) shall perform reliably under any likely combination
of fault conditions so that there is no shock hazard. Compliance
with this requirement shall be assured by one of the following:

1.    The design and construction of the fixtures; or

2.    The use of a ground-fault circuit-interrupter. Definition.
A "ground-fault circuit-interrupter" is a device whose function is
to interrupt the electric circuit to the load when a fault current to
ground exceeds some predetermined value that is less than that re-
quired to operate the overcurrent protective device of the supply
circuit.