Hanna Instruments HI 9912 - Manual (Page 11)

11
ALARM DOSING TIME
MINUTES
1 10
2.5
5
7.5
ALARM
ON
OFF
MAIN POWER SUPPLY CONNECTION
• Before Before Before Before Before connecting the unit to the mains, make sure connecting the unit to the mains, make sure connecting the unit to the mains, make sure connecting the unit to the mains, make sure connecting the unit to the mains, make sure
that the controller is completely wired that the controller is completely wired that the controller is completely wired that the controller is completely wired that the controller is completely wired and that all
connections for pump, alarm, electrode, etc. have been made.
• For 220-240V, short the L1 and N1 termi-
nals. Then wire the external power supply
to the three terminals.
EXTERNAL ELECTRICAL
DEVICE ACTIVATED BY
AN ALARM CONDITION
pH
0
1
2
0
100
200 mV
ALARM
pH
0 SECONDS mV 200 0 TIMER MINUTES 90 PROPORTIONAL SETTINGS 1 10
2.5 5 7.5
0 SECONDS pH 2.0 0 TIMER MINUTES 90 PROPORTIONAL SETTINGS 1 10
2.5 5 7.5
500 900 CAL ALARM ON
OFF SET
FEED mV
OFFSET SLOPE ALARM ON
OFF 0.5 1.5
pH
HI 9912
mV
ORP
ALARM
8 SET
FEED
ALARM
6
7 ACID
OXID 700
50 150
SET pH
SET ORP
ALARM
LINE
• If the actual measurements are above or below the setpoints by
a margin greater than the user-selectable alarm threshold, the
alarm terminal is activated, triggering the mechanism of your
choice. The alarm LED lights also come on. Due to the Consent
Consent Consent Consent Consent
feature feature feature feature feature, if the pH is in alarm, both the pH and ORP relays will
be disactivated. However, if only ORP is in an alarm condition,
only the ORP relay will be disactivated.
• The alarm ON/OFF switch is only to disable the disable the disable the disable the disable the
alarm terminal alarm terminal alarm terminal alarm terminal alarm terminal (e.g. the buzzer will not sound).
However, all other functions such as disactivation of
the dosing relays remain unvaried.
• If the pH ON/OFF switch is in the off position, the buzzer/light
will not come on when the pH value is out. The alarm will be
sounded for ORP, unless likewise, the ORP switch is in the off position.
• The controller provides for automatic fail-safe automatic fail-safe automatic fail-safe automatic fail-safe automatic fail-safe security by
activating the alarm if there is a power failure, regardless of
whether the NC or NO configurations were chosen.
• The alarm is also activated if one or both of
the independent overdosage times are ex-
ceeded. The maximum time that the relay
contacts remain active continuously (overdos-
age timers) can be set from 1 to 10 minutes.
• Once in an alarm condition, the alarm contact remain activated
until the switch is manually put in the off position or the
measurements return to normal values.