4230 Flow Meter
Section 4 Optional Equipment
4-10
NO [normally open] and NC [normally closed] contacts) means
you can switch loads either on or off. Relay contacts are rated 3
Amperes at 24 volts AC or DC. The alarm box operates on 12
VDC supplied from the flow meter. Current consumption in
standby condition is approximately 10 mA. In alarm, current
increases to 190 mA. You can connect as many as four alarm
boxes to a flow meter, if the flow meter is powered from the AC
line.
Note
1. Do not use the alarm box if your flow meter has a modem or
uses FLOWLINK software (through either a modem or laptop
computer).
2. Use the alarm box with caution in battery-powered installa-
tions, as it will significantly increase power consumption.
In standby condition, an alarm box consumes about one
ampere-hour of battery capacity in four days (or reduces capacity
approximately 25%). In alarm condition, one alarm box will com-
pletely discharge a fresh (4 Ah) battery in 21 hours. Isco recom-
mends using only one alarm box in a battery- powered
installation, and you can expect to change the battery more
often.
4.6.1 Installation The High-Low Alarm Relay Box is enclosed in a high-strength
plastic box. Mount the unit with corrosion-resistant hardware
through the two holes in the stainless steel mounting plate
attached to the case. Two threaded holes in the case allow the use
of either
1
/2" conduit fittings or compression bushings. While the
alarm box is suitable for use in damp locations, do not install it
where there is any possibility of submersion. Where tempera-
tures are expected to fall below freezing, Isco recommends instal-
lation of the alarm box indoors or in a heated location, as the
manufacturer of the microprocessor does not specify its operation
below 32° F (0° C).
WARNING
Hazard of electric shock! Use the relay contacts for low
voltage (24 V) pilot duty only. Do not wire 120 VAC or higher
voltages to the relay contacts.
4.6.2 Wiring to a 4200 Series
Flow Meter
Connecting the High-Low Alarm Relay Box to a 4200 Series Flow
Meter requires a cable and an M/S connector. A special cable, 25
feet long, is available from Isco. On one end of the cable is a
4-pin, male M/S connector. Plug this connector into the Rain
Gauge connector on the flow meter. The other end of the cable
has three stripped wires. Attach them to the alarm box according
to the instructions in the alarm box manual.
To Next Page
Loading...
