Hach 900 MAX - Manual (Page 101)

Section 7
Page 99
8990mnt.fm Internal Maintenance Items
Electrostatic Discharge (ESD) Considerations
To minimize ESD risks,
maintenance procedures not
requiring power to the sampler
should be performed with power
removed. Delicate internal electronic components can be damaged by static electricity,
resulting in degraded instrument performance or eventual failure.
The manufacturer recommends taking the following steps to prevent ESD
damage to your instrument:
• Before touching any instrument electronic components (such as
printed circuit cards and the components on them) discharge static
electricity from your body. This can be accomplished by touching an
earth-grounded metal surface such as the chassis of an instrument,
or a metal conduit or pipe.
• To reduce static build-up, avoid excessive movement. Transport
static-sensitive components in anti-static containers or packaging.
• To discharge static electricity from your body and keep it discharged, wear
a wrist strap connected by a wire to earth ground.
Handle all static-sensitive components in a static-safe area. If possible, use
anti-static floor pads and work bench pads.
7.4 Internal Maintenance Items
The following items require access to the inside of the case for service:
• Fuses for the RS485 and analog interface connectors (if equipped)
• Internal desiccant module
• RAM memory batteries
• System upgrades (4–20 mA, modem, alarm relays, etc.)
• Circuit board repair
7.5 Removing and Opening the Controller
CAUTION
Always power the unit OFF and
then disconnect all cables from
the sampler before removing the
controller. ATTENTION
Débranchez toujours l'alimentation de l'analyseur d'echantillonneur et
débranchez tous les câbles de l'analyseur avant de déposer l'unité de
commande.
To remove the controller from the refrigerator:
1. Turn the unit off by pressing the OFF key.
2. Disconnect and remove all cables to the controller housing, including the
distributor/full bottle shutoff cable.
3. Disconnect all tubing.
4. Remove the two refrigerator mounting screws from the inside of the
refrigerator.
5. Carefully lift the controller assembly up and off the refrigerator.