12
8.2 Notes on pressure transmitter
or cylinder scale
The cylinder pressure at which a gas shortage signal is to be
issued can be set on the monitoring system.
For pressure control panels with automatic switchover,
the switching point for the gas shortage signal must
be higher than the changeover pressure of the mani-
fold, otherwise no signal is given.
The electrical connection of the pressure transmitters or the
cylinder scales and the monitoring system may only be done
by respecting the operating instructions.
Further information on this can be found in the operating
instructions for the ALMS or ALMS Libra.
8.1 General operation of the gas shortage
warning device
The monitoring system consists of the pressure transducers
or a scales (ALMS Libra), the ALMS and the electrical signal
cables, for combustible gases as a blue cable in intrinsically
safe design.
The gas shortage warning is used to signal the emptying of
cylinders and to inform the operating personnel of the im-
pending changeover. This is done by means of an acoustic
signal (buzzer) and an optical signal (light emitting diode) on
the signaling device.
In the case of signaling devices that are connected to pres-
sure pressure transmitters, the current content (pressure) is
also directly displayed. These devices also have a second
pre-alarm.
The acoustic message (buzzer) can be acknowledged on the
signal device. However, the “Gas low” LED does not go out
until a full cylinder is connected.
The signal unit and the isolating switch must always
be outside the hazardous areas.
The adapter(s) for the pressure transmitter can be mounted
on the pressure manifold in different places. locations, de-
pending on the design of the pressure control panel.
An example is shown in the graphic below.
M 16
x 1,336
Innen
M 16
x 1,336
IG
8 Operation of the gas shortage warning device
To Next Page
Loading...