Metex 8760CLP Total Free Chlorine & pH Analyzer - Manual (Page 13)

AQUAMETRIX INC.
1-800-742-1413 www.aquametrix.com
13
ANALYZER WIRING
Please refer to drawing D5040276 and perform the following:
1. The 8760CLP requires 115 VAC or 230 VAC power to be hooked up to TB400. Power consumed is
less than 1 A so generally 16 gauge wire is OK (consult local electrical codes for verification). For
stable operation, the microprocessor needs a good earth ground.
CAUTION: Confirm that the 115/230 VAC switch is correctly set for your feed.
2. If required, connect the two relay contacts; as supplied, they are not powered. They are typically
used as L1 (HOT) circuit ON-OFF switches, in NO (normally open) configuration to control the
chlorine or acid (pump/valve). Best practice uses a separate circuit to isolate the sensitive sensing
circuits from any pump or solenoid inductive surges however, as a convenience for light loads, a 3 A
circuit fuse can be installed at F402 to feed the 8760CL L1 HOT to COM on relay A.
Alarm A contact TB300, closest to AC lines.
Alarm B contact TB301.
3. If required, connect the two-isolated 4 mA to 20 mA outputs, these are 24 VDC.
Output 1, TB303, closest to the relays.
Output 2, TB304.
4. Connect the inputs.
Chlorine sensor is direct connected to the analyzer via a 5-pin DIN connector.
pH sensor is direct connected to the analyzer via a BNC connector.
Sensor Mounting
Optimum sensor performance with minimum user effort is provided through the use of the factory
integrated sample system; 35.5 cm x 66.0 cm (14 in x 26 in) CPVC sample panel with pressure
regulating valve, flow setting valve, atmospheric break, grab sample point, drain, plus dual flow cell
housing the chlorine and pH sensors. The chlorine sensor and pH sensor are fixed in the flow cell via a
1 in MNPT CPVC quick connect insertion fitting.
The sensors are mounted within the sensor lead length, as near as possible to the chlorine analyzer. The
flow cell is arranged so that the sensors are mounted on a 45-degree rising line, with the sensor's tip
down at an angle anywhere from 15 degrees above horizontal to 15 degrees vertical. 45 degrees above
horizontal is best because air bubbles will rise to the top and grit will sink, both bypassing the sensor.
The pressure-regulating valve installed before the flow cell functions to control and stabilize flow. The
atmospheric drain allows for the collection of representative samples without disturbing sample
conditions and acts as a vent for bubbles. The drain line should be larger than the sample line to allow
for purging of sediments, bubbles, biologicals and other debris.
Sensor Wiring
The basic wiring scheme for AquaMetrix chlorine sensor and pH sensor is shown in drawing D5040276.
This wiring scheme is intended for cable lengths less than 20 meters (65 feet) where electrical
interference is low. The chlorine sensor has a 5-pin DIN connector and the pH sensor has a BNC
connector. This allows the sensors to be connected and disconnected easily at the analyzer.
Take care to route all signal wiring away from AC power lines, to minimize unwanted electrical
interference. Avoid twisting the sensor lead, to minimize possibilities for broken wire. Make sure that
the sensor connections are clean and tight.