ED510- GAS DETECTOR
ED510 IM REV 2 - 23.08.2017
7
WATER LEVEL DETECTION
The float switch should be mounted as low as possible in the bilge and requires approx. 5mm. of travel of the float to cause
operate.
The ED735 float switches have 1K5 resistors in series with the switch and are potted in epoxy resin to prevent ingress of moisture
etc. The switches are provided with 2m. of cable and as far as is practical this cable should run vertically upwards to a junction
box (which should be waterproof) well above the possible level of bilge water. The final junction box should have a 4.7Kohm
resistor fitted so that the main zone wiring can be monitored. N.B. The wires from the zone line junction box to the switch are not
fault monitored and should therefore be tested at regular intervals. Sensors with E.O.L resistor fitted can be used to give fault
monitoring of last sensor.
On completion of installation it is important that both short circuit and open circuit faults are simulated and correct alarm operation
checked. In addition the float switches should be checked by immersing in water. Lifting the float manually does not check float
buoyancy!
The magnetic circuit within the float allows either normally closed or normally open operation. The float has been set during
manufacture to give a normally open condition when in the lower position. Thus when the float is raised the circuit will be made
and the 1.5Kohm resistance will be connected across the zone line. If necessary for special applications the float switch may be
reversed thus giving normally closed operation.
AUTOMATIC BILGE PUMPING
Each zone has voltage free 2A@ 30VDC non inductive load contacts which can be used for the automatic operation of bilge
pumps. An external relay suitably rated will be required for bilge pumps taking in excess of 2A. The onboard relay can also be
used to operate a Xenon Beacon mounted externally (as high as possible). Alerting other boat users etc. when the vessel is
unmanned.
WIRING TYPICAL FLOAT SWITCHES
Control unit
zone terminals
ED735 float switches
4K7
E.O.L
