WIKA TIF52 - Handbuch (Seite 18)

18 WIKA operating instructions models TIF50, TIF52
GB
14009686.02 03/2012 GB/D
7. Electrical connection
WARNING!
Observe the safety-relevant maximum values for the connection of the power
supply and the sensors defined in chapter 9.1 "Model overview and their
approvals/Safety-related maximum values".
When working on the field instruments (e.g. installation/removal, maintenance work) take
measures to prevent electrostatic discharge from the terminals.
WARNING!
Carry out mounting work only with power disconnected!
Use the recommended cables and tighten the cable gland. Lead the connecting cable
downward before of the cable gland in order to provide additional protection of the device
against penetration of liquids. Rain water and condensed water can thus drip.
The device is connected by means of a commercially available two-wire cable without
screen. If electromagnetic interference exceeding the test values of EN 61326 for industrial
areas is to be expected or the HART ® multidrop mode is used, a screened cable must
be used. Use cables with round cross section. An outside diameter of cable of 5 ... 9 mm
(0.2 … 0.35 inch) guarantees the tightness of the cable gland. When using other diameters
or cross sections, the gasket must be replaced or a suitable cable gland must be used.
Connect the cable screen on both sides to earth potential if a screened cable is required.
Connect the screen in the sensor directly to the internal earth terminal. The external earth
terminal of the case must be connected with low impedance to the equipotential bonding.
CAUTION!
If equipotential bonding currents are to be expected, a ceramic capacitor (e.g.
1 nF, 1,500 V) must be used for the connection on the evaluation side. The
low-frequency equipotential bonding currents are thus suppressed, but the
high-frequency interference signals remain.
7. Electrical connection