7
Installation
Page 108
gas-lab
Q1
If necessary for wage according to local metrological approval, the plugs for
connecting transmitter cables, could be secured by official adhesive labels, or
alternatively, by wire sealing.
Please consider the relevant installation regulations when arranging the wiring.
The lines must be tensile stress-free and must be provided with a bend
protection, if the
gas-net
device is mounted in a hinged bay. Dimension the
cable length in such a way that there is no tensile stress on the cable during the
swinging of the hinged bay.
We recommend to conduct the lines coming from the transmitters on transfer
terminals in a control cabinet and to connect them from there to the Q1 device.
These terminals, however, have to partly comply with the EX-regulations and
may need to be officially sealed in addition.
7.2.1 Power supply and protective earthing
Operate the
gas-lab
Q1 with a nominal voltage of 24 V DC.
The connection of 24 V is implemented via the terminals
+
and
-
on the back of
the device, and must be externally protected against short circuits with 1 A.
Connect the protective earth to
PE
of the power supply terminal for equipotential
bonding.
A fuse with 0.63A/TT for a device with a width of 1/3 and a fuse with 0.8 A/TT for
a device with a width of 1/2 are provided, respectively. The fuse is inaccessible
from outside for protection reasons. This is why each device should be
individually connected in a cabinet via an accordingly dimensioned automatic
circuit breaker (1 A).
7.2.2 Process boards
The process board equipment of a Q1 depends on the tasks the device is
supposed to accomplish. Generally, it depends on the mounting width of the
device casing, how many process boards can be built in: A 1/3 mounting width
casing accommodates up to three process boards whereas a 1/2 mounting
width casing accommodates up to six process boards.
Altogether, only up to four boards of the types EXMFE4 and MSER2 can be
employed in a device.