System Setup - ABB CalMaster Instruction Manual

...2 INSTALLATION
2.2.4 System Setup (Fig. 2.6)
Warning. Care is needed when
CalMaster is used with cathodically protected
MagMasters.
Cathodically protected installations, wired as
directed in the MagMaster manual, which
isolate the sensor using earthing flanges, are
electrically earthed and do not pose any safety
issues.
When apparatus, such as CalMaster or the
PC, are connected to systems which 'float' the
sensor at the cathodic potential, this apparatus
will also float at the cathodic potential and
therefore must
accidentally grounded.
With the adaptor PCB installed in the MagMaster
Transmitter as detailed in Section 2.2.2, and the
sensor cable plugged into the adaptor as for
normal operation:
Sensor
6
not be grounded
MagMaster
Fig. 2.6 Connection Details for Initialisation
a) Connect lead 3 of the CalMaster to the
MagMaster 9-pin D-Type socket. The three
small probes should not be connected until
requested to do so by the CalMaster software.
For details of when to connect these probe
leads, follow the instructions on the provided
software – see Section 3.2. For details of
where to connect the probe leads, follow the
'on-line help' under the heading, 'test lead
connections'.
b) Connect the 9-Pin D-Type socket on the
CalMaster to a computer (Serial Comms
Connection).
or
Note.The use of CalMaster with a line
powered desktop PC, as opposed to a
portable, battery powered PC, is not
recommended, as the resulting ground (eqrth)
loop can corrupt the sensitive CalMaster
measurements.
In these circumstances, an external RS232
isolator between the PC and the CalMaster will
effect a solution
CalMaster
CalMaster
1 2 3 4
Sensor
Test Lead Set