Connecting To Power Supply; Preparing The Connection - Vega VEGAWELL 52 Operating Instructions Manual

5 Connecting to power supply

Safety instructions
Take note of safety
instructions for Ex
applications
Select power supply
Select installation cable
16
5 Connecting to power supply
5.1

Preparing the connection

Generally connect the instrument only in the complete absence of line
voltage.
The instrument is equipped with an integrated overvoltage protection.
For additional protection of the signal circuit, we recommend further
external overvoltage arresters.
•
Type B63-48 (use with VEGAWELL 52 with plastic housing) or
•
Type ÜSB 62-36G.X (use in a separate housing)
In hazardous areas you must take note of the respective regulations,
conformity and type approval certificates of the sensors and power
supply units.
Power and current signal are carried on the same 2-wire conductor in
the suspension cable. The voltage supply range can differ depending
on the instrument version.
The data for power supply are specified in chapter "Technical data".
Provide a reliable separation between the supply circuit and the
mains circuits according to DIN EN 61140 VDE 0140-1.
VEGA power supply units VEGATRENN 149AEx, VEGASTAB 690,
VEGADIS 371 as well as all VEGAMETs meet this requirement. When
using one of these instruments, protection class III is ensured for
VEGAWELL 52.
Keep in mind the following additional influences on the operating
voltage:
•
Output voltage of the power supply unit can be lower under nomi-
nal load (with a sensor current of 20.5 mA or 22 mA in case of fault
message)
•
Influence of additional instruments in the circuit (see load values in
chapter "Technical data")
The instrument is connected with standard two-wire installation cable
without screen. If electromagnetic interference is expected which
is above the test values of EN 61326 for industrial areas, screened
cable should be used.
Make sure that the cable used has the required temperature resist-
ance and fire safety for max. occurring ambient temperature
Use cable with round cross-section. A cable outer diameter of
5 ... 9 mm (0.2 ... 0.35 in) ensures the seal effect of the cable gland.
If you are using cable with a different diameter or cross-section,
exchange the seal or use a suitable cable gland.
VEGAWELL 52 • 4 ... 20 mA