PGX 10 0 A N D PA X 10 0 |
P R E SSU R E T R A N SM I T T ER S | O I/P G X /PA X 10 0 - EN R E V. C
17
6 Commissioning
General remarks
Once the pressure transmitter has been installed, it is put into
operation by switching on the operating voltage.
Check the following before switching on the operating voltage:
• Process connections
• Electrical connection
• Fill the impulse line and measuring chamber of the
measuring cell completely with measuring medium.
The transmitter can then be put into operation.
To do this, the shut-off valves must be actuated in the following
order (in the default setting, all valves are closed):
1
Open the discharge shut-off valve, if present.
2
Open the shut-off valve.
To put the transmitter out of operation, carry out the steps in
reverse order.
In the case of pressure transmitters for absolute pressure
and measuring ranges of
≤
40 kPa absolute, please note that
the pressure measuring cell has been overloaded over a long
period by the atmospheric pressure during transport and
storage. For this reason, you will need to allow a starting time
of approx. 3 hours after commissioning until the sensor has
stabilized to such an extent that the specified accuracy can
be maintained.
When using transmitters with ‘intrinsic safety’ type of
protection, if an ammeter is connected to the output circuit
or a modem is connected in parallel while an explosion hazard
is present, the sums of the capacitances and inductances of
all circuits, including the transmitter (see EC type
examination certificate) must be equal to or less than the
permissible capacitances and inductances of the intrinsically
safe signal circuit (see EC type examination certificate for the
power supply unit).
Only passive or explosion-proof test devices or display
instruments may be connected.
If the output signal stabilizes only slowly, it is likely that a
large damping time constant has been set on the transmitter.
Output signal
If the applied pressure is within the values indicated on the
name plate, the analog output current ranges between 4 and
20 mA.
If the pressure applied falls outside the set range, the output
current will be driven as per defined configurations, as follows:
Output current limits for analog only version
Overload condition
Lower limit: 3.8 mA
Upper limit: 20.5 mA
Default alarm current: 21 mA
Output current limits for HART and analog version
(according to NAMUR NE 43 standard)
Overload condition
Lower limit: 3.8 mA (settable from 3.8 to 4 mA)
Upper limit: 20.5 mA (settable from 20 to 21 mA)
Alarm current
Lower alarm value: 3.6 mA (settable from 3.6 to 4 mA)
High alarm value: 21 mA (settable from 20 to 22.8 mA)
Default setting: high alarm current
NAMUR NE 43 defines as alarm limits the lower
≤
3.6 mA and the
upper
≥
21 mA.
Risk connected to any deviation from NAMUR NE43 thresholds
of the alarm current limits falls under Customers’ responsibility.
The graphical user interface (DD or FDI) can be used to
diagnose the error.
A brief interruption in the power supply results in
initialization of the electronics (program restarts).
Zero/Span and write protection
There is only one push button behind the display. It changes its
function depending on the presence of the display.
When the display is installed, it works as hardware write
protection switch. When the write protection is disabled, and
it is kept pressed for some 1 second, then the write protection
becomes enabled. In the opposite logic, when the write
protection is enabled, and the button is kept pressed, then the
write protection becomes disabled. This enable/disable
condition can be observed/confirmed by looking at the lock
symbol appearing or disappearing on the top line of the
display.
Write protection prevents the configuration/modification of
device data from being overwritten by unauthorized users. If
write protection is enabled, both local and remote writings are
refused. The Z (Zero) and S (Span) button cannot be used to set
new range values because their writing is disabled while their
use to enter and navigate into the local easy setup menu for the
read/review of the device parameter setting is still allowed.
However, when write protect is enabled, it is still possible to
read out the configuration data using graphical user interface
or communication tools (DD or FDI based).
Transmitter without display requires the communication tool to
activate write protection.
NOTICE
NOTICE
