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5 Connecting to power supply
WIKA Operating Instructions - Process pressure transmitter CPT-2x
5 Connecting to power supply
5.1 Preparing the connection
Always keep in mind the following safety instructions:
•
Carry out electrical connection by trained, qualified personnel
authorised by the plant operator
•
If overvoltage surges are expected, overvoltage arresters should
be installed
Warning:
Only connect or disconnect in de-energized state.
The voltage supply and the signal transmission are carried out via the
four-wire, screened connection cable from the master sensor.
You can find the data for this signal circuit in chapter "
Technical data
".
The instrument is connected via the supplied four-wire, screened
cable. This cable is absolutely necessary for reliable functioning of the
electronic differential measurement.
Use a cable gland suitable for the cable diameter to ensure the seal
effect of the cable gland (IP protection).
The shielding of the cable between master and slave sensor must
be connected on both ends to ground potential. In the sensor, the
shielding is connected directly to the internal ground terminal. The
ground terminal on the outside of the housing must be connected to
the ground potential (low impedance).
Metric threads
In the case of instrument housings with metric thread, the cable
glands are screwed in at the factory. They are sealed with plastic
plugs as transport protection.
Note:
You have to remove these plugs before electrical connection.
NPT thread
In the case of instrument housings with self-sealing NPT threads, it is
not possible to have the cable entries screwed in at the factory. The
free openings for the cable glands are therefore covered with red dust
protection caps as transport protection.
Note:
Prior to setup you have to replace these protective caps with ap-
proved cable glands or close the openings with suitable blind plugs.
On plastic housings, the NPT cable gland or the Conduit steel tube
must be screwed into the threaded insert without grease.
Max. torque for all housings, see chapter "
Technical data
".
Safety instructions
Voltage supply
Connection cable
Cable screening and
grounding
Cable glands
