7-
Fault Finding
All fault finding must be conducted by a competent person or qualified Electrical Engineer.
Failure of Lamp to ignite
In the event of the lamp failing to light the following steps should be taken:
1)
Check that the mains supply is connected to the input of the ballast gear and check all
connections as per the wiring diagram. On operation if the lamp does not light, switch off mains
supply and check all fuses;
2)
Check the searchlight head. On your command get an operator to switch on the light for
approximately 2 seconds. During this time listen for any noise (cracking or hissing) coming
from within the barrel. If this arcing is heard switch off the supply at the mains. Remove the
rear bezel to expose the two supply leads from the ignitor to the lamp. Using a dry cloth wipe
these leads to remove any dust, moisture or condensation that may have formed around the
inside of the barrel. Replace the rear bezel, ensure the latches are secure, and perform the
check again, listening for the cracking. If the lamp still fails to ignite, switch off at the mains and
replace the lamp in accordance with the safety procedures within the manual and the
manufacturer’s information.
Any further tests to be carried out with regards to lamp failure must be conducted by a
competent electrical engineer and should not be carried out in an explosive atmosphere.
3)
Before a metal halide lamp will ignite, the electrically insulated gas between the electrodes
must be ionised. This is done by the ignitor which produces a high frequency voltage (up to
30,000 volts or higher). Switching the lamp on activates the ignitor. A cracking or hissing noise
should be heard. The ignitor is housed within the rear of the searchlight barrel. If found to be
faulty a new ignitor must be fitted.
Failure of Remote Focus Facility (Optional facility)
The remote focus mechanism is controlled by a small electric motor situated on the lampholder
assembly within the searchlight barrel. If the focus of the light fails the following procedure should
be adopted:
1)
Remove the front bezel from the searchlight barrel and examine focus mechanism. If parts
have become loose, tighten fasteners. The mechanism operates on a cam action and this
should be checked for correct positioning;
2)
If the mechanism is okay, check the supply to the motor. This can be done by simply placing a
multimeter across the motor terminals;
3)
If supply is present, this indicates that the motor has failed. Replace the focus motor ensuring
that the assembly is correct;
4)
If no supply is present, check the transformer in the control unit. Using a multimeter check the
supply into and from the transformer. If found to be faulty, replace the transformer and check
operation of focus mechanism.
5) If no supply is present there is a fault at the mains or the internal wiring of the control gear.
This should be examined and rectified accordingly.
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