Independent liner direct power supply is suggested to adopt for the power supply of
pressure transmitter, over large resistive load will result in a large pressure drop, so it
requires to calculate the all-in resistance of signal cable, display meter and other
record and display equipment, to ensure the voltage provided to the pressure
transmitter accord with normal operating requirements.
4-20mA Two wire
Three wire Current /voltage signal
Four wire Current /voltage/digital signal
Intrinsic safety 4-20mA Two wire
Measurement signal is abnormal which should judge the process pressure is
abnormal, measuring system error or influence of installation environment or abnormal
in the pressure transmitter, then analyze the reason and take corresponding
measures.
No signal output, process pressure changes but no measurement corresponding
change, or , it may be an abnormal pressure transmitter, it change does not correspond
needs to check the power supply voltage, wiring, power consumption and load
resistance whether they meet normal operating requirements. Also need to check if
there is leaks and pressure impulse line blockage, shut-off valve not turned on, etc.
Signal output error is too big or it exceeds need to check the power the normal range,
supply voltage, power consumption and load resistance whether they meet normal
operating requirements, the measuring range setting, if adjustment is correct. Also
need to check if there is leaks and pressure impulse line blockage, shut-off valve not
turned on, rapid temperature fluctuations, etc.
If there is any question, please contact Shanghai LEEG Instruments Co.,Ltd. Tel: 86-21-31261976 Fax: 86-21-31261975 Email: info@leeg.cn, sales@leeg.cn
The signal connection of intrinsic safety instruments needs to refer to
isolation safety barrier factory instructions.
Using cable with shielded twisted-pair signal has the best effect, to avoid ground loop,
shielded layer adopts single-end grounded.
Transient resistance built-in module only effect in the case of good grounding, metal
shell and internal grounding terminals is used to the nearest grounded directly.
In order to avoid the liquid flowing along the
cable, which will cause waterproof joint
effusion or flow into terminal box, an U-
shaped ring needs to configured between
pull box and pressure transmitter as in the
picture, and make the U-shaped bottom
under the pressure transmitter. Considering
the needs of maintenance and replace,
enough cable length needs to reserve.
Using flame proof pressure
transmitter in dangerous situations,
need to use metal flexible explosion-
proof tube to connect the signal cable
into pull box and lead to the safety zone.
Please refer to the label for specific signal outline type.
+
-
1
2
1
2
3
+
-
1
2
1
2
3
Label
Label
Label
Label
+
-
S+
1
2
3
1
2
3
+
-
S+
S-
Red
Black
Yellow
Blue
Label Two wires Three wires Four wires
1/Brown Power+Power+Power+
2/White Signal-
3/Blue +
Signal Signal+
4/Black Power-Power-Power-
Label Two wires Three wires Four wires
Red Power+Power+Power+
Black Power-Power-Power-
Blue Signal+Signal+
Yellow Signal-
For example choose DIN43650
ŒConnect the positive power supply P+（ ）
to the terminals 1 of pressure transmitter;
Connect the positive signal module (S+)
to the terminals 2 of pressure transmitter;
ŽConnect the negative signal module (S-)
to the negative power supply (P-).
1
2
1
2
3
3
3
3
4
Brown
black
Blue
White
PWR/
COMM
TEST
Label Two wires Three wires Four wires
P WR+ Power+Power+
P WR- -Powe r Power-
TEST+ +
Signal
Label Two wires Three wires Four wires wires
+Power+Power+Power+
-Power-Power-Power-
ASignal+Signal+
BSignal-
Adjustment needs caution. Not all types of pressure transmitters have
adjustment function.
！
！
！！
！
Reference standard pressure source,
adjust the potentiometer to calibrate the
pressure transmitter, maximum adjustable
range is + / - 5%. Using a straight
screwdriver, forward or reverse rotate to
increase or decrease the range. The
potentiometer belongs to precision device,
which needs fine-tuning.
Through LCD buttons, terminal box
external buttons or software as HART
protocol, it is convenient for range
adjustment. For detailed operation, please
reference instructions of display meter,
HART protocol and so on.
Red
Black
Blue
Yellow
Filter
！The reference pressure is the current atmospheric pressure for gauge pressure
transmitter.Be careful, avoid the filter dropping off, and kept dry.
For example choose DIN43650
ŒConnect the positive power supply P+（ ）
to the terminals 1 of pressure transmitter;
Connect the positive signal module (S+)
to the terminals 2 of pressure transmitter;
ŽConnect the negative signal module (S-)
to the negative power supply (P-).
Please note! The signal connection
of intrinsic safety instruments needs to
refer to isolation safety barrier factory
instructions.
For example choose DIN43650
Œ Connect the positive power supply P+（ ）
to the terminals 1 of pressure transmitter;
Connect the negative power supply P-（
）to the terminals 2 of pressure transmitter,
connect the negative signal module (s-) to
the negative power supply P- ;（ ）
ŽConnect the positive signal module (S+) to
the terminals 3 of pressure transmitter;
For example choose cable connect directly
ŒConnect the positive power supply P+（ ）
to red wire of pressure transmitter;
Connect the nega tive power supply P-（
）to black wire of pressure transmitter,;
ŽConnect the positive signal module
(S +) to blue wire of press ure tran smit te r;
Connect the nega tive signal module (S-
) to yellow wire of pressure transmitter;
Pressure Transmitter/ Quick Installation Guide
A B
+ -
A B + -
A
