Hach 900 MAX Electrostatic Discharge ESD Considerations, Internal Maintenance Items, Section

Section 7

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	ATTENTION
Always power the unit OFF and	Débranchez toujours l'alimentation de l'analyseur d'echantillonneur et
then disconnect all cables from	débranchez tous les câbles de l'analyseur avant de déposer l'unité de
the sampler before removing the	commande.
controller.
	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.

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8990mnt.fm	Internal Maintenance Items