INSTALLATION
Siting of the equipment should be chosen
with regard to the following points.
a. Away from sources of heat with room
for adequate air circulation.
b. Within easy reach for operating and
maintenance personnel.
c. Connecting cables to be electrically
shielded ie: M.I.C.C., steel wire armoured,
screened cable or steel conduit.
Note: Sensor cables should not be run
in the same ducting as power cables.
CALIBRATION
1. Connect a digital voltmeter (miIIivolt
range) to the + and – test terminals
(2 wire system) or X and Y test terminals
(3 wire system)
For 3 wire systems the CV is preset in
the current source
mode.
2. In clean air check that the DVM reads
4mV, if not adjust the 4mA potentiometer
on the CV transmitter board.
3. Apply test gas and wait until a maximum
DVM reading is
obtained, if necessary adjust the 20mA
potentiometer for the
required mV reading for the calibration
gas used (see range/reading on test certificate
or printed on the CV circuit
board).
4. For oxygen level monitoring remove
the sensor terminal
connector from the PCB J4 and adjust the
4mA potentiometer
for 4mA (4mv). |
Reconnect the cell and
allow reading to stabilise adjust the
DVM reading for 17.3mA (20.8% Vol. ambient
oxygen) using the 20mA potentiometer.
Where a Digital panel meter is fitted
readings should be taken directly from
the readout and if required adjusted using
the 4-20mA potentiometers.
ADDITIONAL RELAY BOARD ALARMTRIP POINT
ADJUSTMENT
This level will normally be set at 20%
of the range reading i.e. 7.2mA.
1. Connect the DVM as above, using the
4mA potentiometer adjust for the required
trip level.
2. Adjust the alarm level potentiometer
until the alarm LED just comes on.
3. Using the 4mA potentiometer re-adjust
the DVM to 4mV.
The above adjustment may be carried out
in house by connecting the CV transmitter
directly to a DC power supply.
Should a full board be required to operate
on a 2 wire loop then the relay must be
disabled - remove JP2
Gas Type Programming – Works/preset.
CO. H2S, SO2. H2 remove R4, R6, R15, R28,
R29, R10
HCN remove R4, R6, R8, R15, R28, R29,
R10
NO2, CL2 O3, remove R4, R7, R11, R28,
R29, R10
NO, HCL, C2H4O Remove R3, R4, R6, R12,
R15, R28, R29, R10 |
12-30v DC - 24v nominal
