Hach 900 MAX, Instrument Manual

Page: 93 / 160

Section 6
Page 91
8990cm.fm
Alarm Relays
Figure 27 Single Relay Wiring Inside the Relay Junction Box
6.4.2 Alarm Relays Programming
Program alarms activate based on certain conditions (low battery, low
memory, etc.). When an alarm is tripped, an action is initiated (report via
modem, dial a pager, or set a relay). There are two types of alarms: Trouble
Alarms and Set Point Alarms.
6.4.2.1 Trouble Alarms
Trouble Alarms initiate an action when a trouble condition occurs. For
example, a relay may close when the memory is full. Refer to
Troubleshooting
and Error Messages on page 127 for more information on trouble alarms.
1. From the Main Menu, select
SETUP > ADVANCED OPTIONS > ALARMS.
2. Select one of the trouble conditions.
3. Select an action to occur when the alarm is activated. The table below
lists each Trouble Condition. Refer to
Appendix C on page 127 for causes
and solutions.
6.4.2.2 Set Point Alarms
Set Point Alarms look for trip points to be reached (either high or low or both)
before initiating an action. For example an initiated action may be the closing
of a relay when the water level exceeds 60 cm (24 in.) or drops below 10 cm
(4 in.) Set Point Alarms activate when a user-definable high and/or low set
point is reached.
Trouble Conditions:
• Low Main Battery • Memory Battery
• Low Slate Memory • Slate Memory Full
• Modem Failure • Missed Sample
• Purge Failure • Jammed Distributor
• RS485 Timed Out
Alarm Actions:
• Set Relay #1 • Set Relay #2
• Set Relay #3 • Set Relay #4
• Report Via Modem