How To Set The Zero - ABB 2600T Serie Bedienungsanleitung

HOW TO SET THE ZERO

The procedures described below do not affect the physical pressure shown (PV VALUE); they only correct the analog output
signal. For this reason, the analog output signal may differ from the physical pressure value (PV) shown on the digital display or
the communication tool.
In case the plant procedure requires to correct this, set the communication board dip switch nr.3 in 1 (up) position before performing
the below procedures.
ZERO BASER CALIBRATED DEVICES
(eg. 4 .. 20 mA = 0 .. 250 mbar)
The below procedure has not be followed when dealing with absolute pressure transmitters (266A / V / N)
1. Insulate the transmitter from the process and vent the transmitter measuring chamber/s to atmosphere.
2. Check the output signal of the transmitter, if it is at 4 mA (or PV= 0) you do not need to re-zero the transmitter;
if the output is not at zero follow the below procedure:
a. Unscrew the data plate fixing screw on the top of the transmitter housing.
b. Rotate the data plate to get access to the push buttons.
c. Be sure that the write protection rotating switch is set to write enable.
d. Push the zero (Z) button on top of the transmitter for at least 3 seconds.
e. The output will go to 4 mA, and if the Integral Display is present, the message "OPER DONE" will appear.
If nothing happens check the write protection rotating switch, it is probably set to write disable.
In case of other diagnostic messages, refer to the instruction.
3. Once the "Zero" operation has been accomplished the transmitter needs to be reconnected to the process.
4. Close the vent / drain valves that may have been opened
5. Open the insulation valve/s (in case of differential pressure transmitters please follow the following sequence:
open high pressure side insulation valve,
open low pressure side insulation valve,
close equalizing valve.
NON ZERO BASED CALIBRATED DEVICES
(eg 4 .. 20 mA = - 100 .. 100 mbar)
1. Insulate the transmitter from the process and vent the transmitter
measuring chamber/s to atmosphere.
2. Apply the lower range value pressure (4 mA) from the process
or from a pressure generator. The pressure must be stable and
applied with a high level of accuracy << 0.05 % (observing the set
damping value).
3. Check the output signal of the transmitter, if it is at 4 mA (or
PV= 0) you do not need to re-zero the transmitter; if the output is
not at zero follow the below procedure:
a. Unscrew the data plate fixing screw on the top
of transmitter housing.
b. Rotate the data plate to get access to the push buttons.
Be sure that the write protection rotating switch is set
to write enable.
c. Push the zero (Z) button on top of the transmitter
for at least 3 seconds.
d. The output will go to 4 mA, and if the Integral Display
is present, the message "OPER DONE" will appear.
If nothing happens check the write protection rotating
switch, it is probably set to write disable.
In case of other diagnostic messages, please refer to
the instruction.
4. Once the "Zero" operation has been accomplished the
transmitter needs to be reconnected to the process.
5. Close the vent / drain valves that may have been opened
6. Open the insulation valve/s (in case of differential pressure
transmitters please follow the following sequence: open high
pressure side insulation valve, open low pressure insulation valve,
close equalizing valve.
ABSOLUTE PRESSURE TRANSMITTER REZERO
Absolute pressure transmitter rezeroing is only possible when a vacuum pressure generator is available. It is strongly recommended
to refer to the integral manual before proceeding-.
ZERO
Write Enabled
It is not necessary to remove the cover for this procedure
(Dip switch are already factory set)
2600T Series Pressure transmitters 266 models | SOI/266-XC 9
SPAN
WRITE
PROTECT
Write Disabled