Chapter 8 ___________________________________________________________________ Repair
VAISALA ______________________________________________________________________ 107
Replacing Internal Heater CLH311-115 /
CLH311-230
CAUTION
Servicing the equipment must only be performed by qualified
maintenance personnel.
NOTE
Internal Heater CLH311 is recommended to be replaced indoors.
The internal heater should be replaced if the ceilometer unit has been
generating warnings and alarms, and a malfunction with the operation
of the heater has been detected.
To replace Internal Heater CLH311, you will need a 3 mm Allen-key.
Then proceed as follows:
1.
Open the measurement unit door and confirm that there is an
active internal heater failure. In case of an internal heater failure,
the
CLH ok
LED will be turned off. Refer to Figure 19 on page
99.
2.
Switch the power off with all three switches (F1, F2, and
battery). For the location of the switches, refer to Figure 18 on
page 98 and Figure 19 on page 99.
WARNING
Disconnect the CT3839 power cable before continuing!
3.
Close the enclosure door and remove the measurement unit. To
do this, loosen the three attachment screws (marked A in Figure
5 on page 23) on the back of the measurement unit, disconnect
the blower cable from connector J1 (see Figure 7 on page 25),
and pull out the unit.
4.
As a safety precaution and to ease the replacement procedure,
disconnect the battery and data cables from the CLE311 board.
5.
Remove the metal plate protecting the heater by loosening its
two screws.
