The chlorine dosing relay is activated (Common connected to Normal Open) when
chlorine concentration is under the dosing setpoint. The chlorine dosing use a pro-
portional algorithm that depends on both, setpoint and delta (∆).
The DOSING CHLORINE LED is turned on when the dosing relay is closed.
Note: The chlorine dosing is stopped when the concentration is over Alarm high setpoint or
when a System Error related to chlorine measurement occurs.
Chlorine Dosing Relay
If the situation persists for more than a few samples, the operator should notify maintenance personnel
for investigation of the problem.
Note: When the meter is in alarm mode or in system error mode, the user could directly view
the alarm or error description on the display.
If GSM transmitter is installed and GSM mode is selected, the alarms and errors are sent as
SMS message.
The System Error relay is power-fail safe and is closed when the analyzer is not powered.
INITIAL PREP
ARA
TION AND INST
ALLA
TION
Acid/alkali Dosing Relay
Acid/alkali dosing relay is activated (Common connected to Normal Open) depending
on the setpoint and selected delta. If the analyzer is set to dose acid, the relay
is active when the pH value is over the setpoint. If alkaline is dosed, the relay is
activated when the pH value is under the setpoint.
The DOSING ACID/ALK. LED is turned on when the dosing relay is closed.
Note: The acid/alk dosing is stopped when system error related to pH occurs.
Recorder Output
The recommended recorder hookup uses a twisted pair shielded cable. The shield should be connected
to the terminal at the instrument end and left open at the recorder end.
To operate with this hookup, the following conditions are required at the recorder end:
• The input to the recorder must be isolated from the chassis ground (earth) of the recorder;
• If the recorder has more than one input, they must be differential inputs.
For
PCA310
,
PCA320
and
PCA330
several type of outputs are available: 0-10 mV,
0-100 mV, 0-1 V, 0-20 mA or 4-20 mA. The recorder output could be assigned to
Cl, pH, Temperature or ORP.(see the right figure)
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