Datcon DT2500 Series, Operating Manual

Page: 11 / 29

DT2500
20171220-V1
11
5. Connecting
5.1. Preparing the connection
Select and prepare
connection cable
Always observe the following safety instructions:
•
When you are going to install instruments in hazardous area or
install instruments which are connecting to instruments are working in
hazardous area you should take note of the appropriate regulations,
conformity and type approval certificates of the DT2500 and other
instrument. The connection must be carried out by trained and
authorized personnel only!
•
Connect only in the complete absence of supply voltage
•
Use only a screwdriver with appropriate head
Take note the suitability of the connecting cable
(Wire cross-section, insulation, etc.).
The wire cross-section should be 0.25-1.5 mm.
You may use either solid conductor or flexible conductor.
In case of using flexible conductor use crimped wire end.
The compensating current can not flow on the cable shield!
The cable shield should only be grounded on one side, preferably on
the instrument room.
Make sure that, the shield should be
continuous, between the source (DT2500) and the connected device
Take note of the corresponding installation regulations for
Ex applications. In particular, make sure that no potential equalization
currents flow over the cable screen. Ground only one side the cable
screen (it’s recommended the transmitter side).
If necessary of grounding on both sides (for suppress very high level,
high frequency interference signals) this can be achieved by use of a
blocking capacitor (e.g. ceramic capacitor 1 nF, 1500 V) or separate
potential equalization. The low frequency potential equalization
currents are thus suppressed, but the protective effect against high
frequency interference signals remains.
The DT2500 device has a very effective interference protection,
therefore grounding both sides of the cable is usually not necessary.
if interference emitting devices operating beside the DT2500 device
(eg inverter) may require the application of the above. Important rule
that the signal cables, control and power cables pass it separately.