Hach 900 MAX - Manual (Page 105)

Section 7
Page 103
8990mnt.fm Replacing the Fuse
7.8 Replacing the Fuse
DANGER
For continued protection
against fire, replace fuses with
only fuses of specified type and
current rating. PELIGRO
Para una continua protección contra incendios, reemplace los fusibles
únicamente por los del tipo y capacidad recomendados.
Medium Delay Fuse, 5 Amp
The main 12 volt line is fused as soon as it enters the controller housing. This
is a 5-amp medium delay fuse (Cat. No. 8753) and is accessible from outside
the case on the back side of the controller housing. To remove the fuse
unscrew the cap on the fuse holder with a flat blade screwdriver.
PCB Fuse Removal and Inspection
Pull the fuse straight out of the holding clips to remove the fuse. The wire
strand inside the glass tube will be broken. Use an ohmmeter to tell for sure if
a fuse needs to be replaced.
7.9 Motor/Gear Box
The motor/gear box requires no regular maintenance. The special formulation
gears are self lubricating and require no oil or grease.
7.10 Internal Desiccant Module
Note: The desiccant module cannot
be recharged by heating. Do not
attempt to bake the desiccant
module in an oven to remove the
moisture as this could be a fire
hazard. The Internal Desiccant Module (Cat. No. 8849) consists of a
moisture-absorbent material inside a poly bag. If the humidity indicator on the
front panel turns pink, replace the module and the back panel perimeter
gasket (Cat. No. 8606). The desiccant module is located under the CPU
board.
7.10.1 Replacing the Desiccant
To replace the desiccant, detach the controller from the refrigerator cabinet,
and remove the screws from the controller bottom panel. Remove the
desiccant bag and replace with a new one. Replace the controller gasket and
cover plate. Reattach the controller to the refrigerator. After replacing the
desiccant module and re-sealing the case, the Internal Case Humidity
Indicator Disc (Cat. No. 2660) should return to its original blue color. If the
humidity indicator is blue the desiccant is dry. Replace the indicator disc if it
fails to return to blue after replacing the desiccant module. To replace the
indicator disc, remove the bottom panel that is held in place by a small clip
and screw.