Commissioning, operation – WIKA DPGT40 User Manual
Page 16
GB
WIKA operating instructions differential pressure transmitter, model DPGT40
16
14093267.01 03/2014 GB/D/F/E
6. Commissioning, operation
6.2 Electrical zero point (4 mA)
The zero point adjustment is made by an adjustment screw in the front, which,
depending on the instrument model, is accessible by loosening the window or the
locking screw. By turning the adjustment screw using a screwdriver the desired zero
point is set.
If the mechanical zero point has been altered via the
adjustment screw, the electrical zero point must be
matched again to the mechanical one.
For this, the differential pressure transmitter must first be
depressurised.
Remove the entire cable cover on the right-hand side
of the transmitter. To do this, undo the screw on the
top of the cable cover cap completely with a slotted
screwdriver (0.6 x 3.5 mm). Remove the screw. Pull the
cable cover , along with the socket insert , out from the
cable socket baseplate .
This isolates the transmitter from the voltage supply.
Take the cable cover cap from the cable cap and
push the socket insert out, downwards, completely
through the cable cap .
Bridge contacts 5 and 6 on the socket insert with a
short length of wire, stripped at both ends (maximum
permissible resistance 30 Ω).
Reassemble the connector in the reverse order. Insert the
connector, with the piece of wire mounted, into the pin
insert . This remakes the voltage supply.
Within a max. of 30 seconds, the new zero point will be
saved within the electronics. During this time, the current in
the loop will rise to 9.5 mA.
The new zero point is maintained, even with a loss of
power, for an extended period.
Once more, disconnect the connector in the order
described above and remove the piece of wire. After again
assembling the connector, the electrical output signal will
once more match the display of the mechanical pointer.
Screw
Cable cover cap
Cable cover
Socket insert
Cable socket baseplate
Sealings
In order that the ingress
protection is maintained, the
seals must be refitted.