Relay connections, Alarm connections – Hanna Instruments HI 9910 User Manual
Page 16
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RELAY CONNECTIONS
• Wire the external device or devices (pumps or electrovalves)
directly to the relay terminal strip of the controller (see 20 -
Functional Diagram). The terminals are powered
terminals are powered
terminals are powered
terminals are powered
terminals are powered and hence
you do not need an external power supply
do not need an external power supply
do not need an external power supply
do not need an external power supply
do not need an external power supply for the pump
or electrovalve. There is one terminal strip for
HI 9910 and
HI 9920 and two for HI 9911.
ALARM CONNECTIONS
• The operator can select an alarm threshold of 0.0
to 2.0 pH for HI 9910 and HI 9911 or 0 to 200
mV for HI 9920 by turning the alarm knob (see 13
of Functional Diagram). If the actual measurements
are above or below the setpoint by a margin
greater than the user-selectable alarm threshold,
the alarm terminal is activated. The alarm can be
selected as normally closed ("NC") by connecting the external
device to the C and NC terminals or normally open ("NO") by
connecting the external device to the C and NO terminals.
• When activated, the alarm contacts will open or close, triggering
the mechanism of your choice. When the alarm is activated
alarm is activated
alarm is activated
alarm is activated
alarm is activated
all other terminals
all other terminals
all other terminals
all other terminals
all other terminals (such as dosing relay etc.) are
are
are
are
are
disactivated
disactivated
disactivated
disactivated
disactivated. The alarm LED light also comes on.
pH
0
1
2
ALARM
MTC
ATC
mA OUTPUT
TEMP. COMP.
4/20
0/20
HI 9910
pH
SECONDS
0
90
45
MTC
°C
-10
80
10
0
30
20
60
70
40
50
0
pH
2.0
0.5
1
1.5
COARSE
FINE
SLOPE
OFFSET
PROPORTIONAL SETTINGS
ALARM
ON
OFF
SET
READ
ACID
DOSING
ALK
SET POINT
ALARM DOSING TIME
MINUTES
1
10
2.5
5
7.5
SET pH
ALARM
LINE
BL DOSING PUMP
pH
0
1
2
ALARM
MTC
ATC
mA OUTPUT
TEMP. COMP.
4/20
0/20
HI 9910
pH
SECONDS
0
90
45
MTC
°C
-10
80
10
0
30
20
60
70
40
50
0
pH
2.0
0.5
1
1.5
COARSE
FINE
SLOPE
OFFSET
PROPORTIONAL SETTINGS
ALARM
ON
OFF
SET
READ
ACID
DOSING
ALK
SET POINT
ALARM DOSING TIME
MINUTES
1
10
2.5
5
7.5
SET pH
ALARM
LINE
EXTERNAL ELECTRICAL
DEVICE ACTIVATED BY
AN ALARM CONDITION
pH
0
1
2
ALARM
MTC
ATC
mA OUTPUT
TEMP. COMP.
4/20
0/20