Installation
7
gas-lab
Q1
Page 119
7.3.4 Vent gas line
During the regular measurement operation the process or calibration gas flows
through the sensor system and is led off via the vent gas line. The diameter of
the vent gas line must be at least 6 mm. The gas flow is indicated by a flow
meter and can be adjusted via a needle valve; the flow meter should show a
rate of about 25l/h.
As an option, a bypass can be installed to speed up the gas sampling. It can be
separately adjusted by means of a flow meter and a needle valve. The gas flow
in the bypass is adjusted depending on gas consumption and measurement
response time.
The vent gas lines of the sensor system and bypass can be separately led to the
outside with a minimum diameter of 6 mm. Alternatively the vent gas lines can
also be combined outside the mounting plate; however, the minimum diameter
of the joint pipe should then be 12 mm.
7.3.5 Electrical connection
An
equipotential
bonding
must
be
implemented
between
sensor
system/mounting plate and Q1 computer. The power supply and the data
communication with the Q1 computer are connected to the explosion-proof
junction box.
The power supply has to be able to supply a current of 4 A at a voltage of 24 V
DC +/- 5 %. The fuse protection is preferably implemented by means of a C6
automatic circuit breaker. Examples for the design of the connecting cable of the
power supply are shown in the table below. The earthing is connected in the
explosion-proof junction box as well as at the power supply.
Power supply cable
Length: 0 - 30 m
Length: > 30 m
Indoor
Ölflex 3G x 2.5 mm
2
Ölflex 3G x 4 mm
2
Outdoor
NYY-J 3 x 2.5 mm
2
NYY-J 3 x 4 mm
2
Examples for the design of the communication line to the Q1 computer are
shown in the table below. The shielding is connected in the explosion-proof
junction box and control cabinet and at the Q1 computer, respectively.
Data communication cable
Max. length: 300 m
Indoor
LiYCY 3 x 2 x 0.5 (TP)
Outdoor
LiYCYv 3 x 2 x 0.5 (TP)