Document UT-MT-0573
Page 21 of 28
Edition 03/13/2012
Supersedes edition 02/09/2010
SLTH – SEMI-FLUSH THRESHOLD LIGHT
INSTRUCTION MANUAL FOR USE, INSTALLATION AND MAINTENANCE
DO NOT OPERATE ON LIVE PARTS!!!
The preferred method of maintaining these lights is replacing each fixture periodically and
systematically and return it to the maintenance shop for renovation.
Field servicing shall be limited to cleaning the prisms.
5.1.
REMOVING AND OPENING THE LIGHT UNIT FROM THE BASE
Remove the fixture from the base by unscrewing the six locking screws complete with
washers. Raise the fixture by using the two lifting tools (P/N 332.4140 or 332.4230)
inserted in the suitable slots provided on the dome. As an alternative, two screwdrivers
can be used.
Disconnect the fixture plug and grounding cable from those inside the shallow base.
Unscrew the leak valve cap and push the valve central pin, in this way the light internal
pressure is the same of the atmospheric pressure. Open the fixture by unscrewing the
three locking screws HSCH M5x16 (fig.1 - n°22). If the lower cover assembly is hard to
remove, it is possible to use two of these screws in two threaded holes close to the locking
holes.
Every time the fixture is removed from the base receptacle and opened, inspect the
following parts:
a) prism: if it is dirty or damaged take provision as described at paragraphs 4.2 - 4.3;
b) all the fixture gaskets: O-Rings between dome and lower cover (fig.1 – n°20); O-Ring
around the dome (fig.1 – n°19); prism gasket (fig.1 - n°4); O-Ring between fixture and
shallow base (fig.7 – n°7); check the integrity and replace them, if necessary, as
described at paragraph 4.5;
c) cable lead with plug and replace it, if damaged, as described at paragraph 4.6.
5.2.
PRIMS CLEANING
5.2.1. Prism outside cleaning
Removing the fixture is not necessary to clean the outer surface of the prisms, and
if already removed is not necessary to open it. Clean the prisms surface with non
abrasive glass product.
5.2.2. Prism outside cleaning
Normally the cleaning of the prism inside surfaces is not necessary because fixture is
watertight. Whenever it is necessary, remember the following rules.
Remove the fixture from the base and open it following instructions of par. 4.1. and
proceed as follows:
