MSA 9010 LCD, Operating Manual

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Control Unit Models 9010 LCD and 9020 LCD 18
Configuration
MSA
GB
STEL average CALCULATION = sum of last 15 readings /15 [any negative values are consid-
ered 0 ppm].
The value of the TWA average will be available after 480 minutes [8 hours] from start-up or after
480 minutes from the setting. TWA in Access Code 4, step 14 [and/or step 18]. The sampling time
for the calculation of the averages is 1 minute.
TWA average CALCULATION = sum of last 480 readings /480 [any negative values are consid-
ered 0 ppm].
Overrange
The purpose of the OVER RANGE function is to indicate when 100 % of the full scale is exceeded,
and, if activated, this exceeding causes the symbol EEEE to be displayed and the external acous-
tic device to be activated, which can then be silenced by pressing one of the UP or DOWN keys.
In the ATEX version, the OVER RANGE indication is always activated.
The reset of all the alarm set-points is commutated automatically into
1M
mode, independently of
the previously made choice, except that it is already in
2M
mode.
The EEEE indication will persist until the signal remains greater than the full scale value.
When the signal falls back below the full scale, the EEEE symbol alternates with the current indi-
cation of the concentration [4 sec.: EEEE; 1 sec.: display of the concentration] and the acoustic
device is activated anew.
When the concentration falls back below the alarm levels and in concurrence with the manual re-
set of one or more set-points, the cancellation of EEEE occurs and the reset modes return as per
configuration.
If necessary, the CAUTION set-point, whose intervention value will be set to 100 % of full scale,
can be used for the remote indication of OVER RANGE.
5.9 Starting the Control Unit
Before energising the Control Unit, make sure that:
-
the mechanical and electrical installation conforms to what is described in section 4 and nev-
ertheless conforms to the prevailing standards.
-
that the setting of the jumpers related to the voltage change and those of the hardware config-
uration conform to the CALIBRATION DATA SHEET included with the Instruction Manual.
-
that the serial number of the Control Unit corresponds to that of the sensor or of the connected
sensor.
After having applied voltage, the Control Unit for about 1 minute performs the self-diagnostics for
each channel in order to check the correct operation of the various circuits and of the signalling
devices.
During this phase, the alarms are blocked, and the 4/20 mA analogue output is placed as
per the configuration of Access Code 4, step 20; the failure indication for the ATEX version
is active.
At the end of the self-diagnostics, the Control Unit is placed in regular operating mode.