5.1 Preparing the connection. Vega VEGACAL 63

Safety instructions

Voltage supply

Connection cable

5 Connecting to power supply

5 Connecting to power supply

5.1 Preparing the connection

Always keep in mind the following safety instructions:

Warning:

Connect only in the complete absence of line voltage.

• The electrical connection must only be carried out by trained personnel authorised by the plant operator.

• If overvoltage surges are expected, overvoltage arresters should be installed.

Power supply and current signal are carried on the same two-wire cable. The operating voltage 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.

Power the instrument via an energy-limited circuit acc. to DIN/EN/IEC/

ANSI/ISA/UL/CSA 61010-1, e.g. via Class 2 power supply unit acc. to

UL 1310 or an SELV power supply unit with suitable external current limitation.

2)

Keep in mind the following additional factors that influence the operating voltage:

• Lower output voltage of the power supply unit under nominal load

(e.g. with a sensor current of 20.5 mA or 22 mA in case of fault)

• Influence of additional instruments in the circuit (see load values in chapter "Technical data")

The instrument is connected with standard two-wire cable without screen. If electromagnetic interference is expected which is above the test values of EN 61326-1 for industrial areas, screened cable should be used.

Make sure that the cable used has the required temperature resistance and fire safety for max. occurring ambient temperature

Use cable with round cross section for instruments with housing and cable gland. To ensure the seal effect of the cable gland (IP protection rating), find out which cable outer diameter the cable gland is suitable for.

Use a cable gland fitting the cable diameter.

We generally recommend the use of screened cable for HART multidrop mode.

2) Class 2 power supply unit: limited voltage and power level, special insulation against circuits with higher voltage. SELV (Safety Extra Low Voltage) power supply unit: limited voltage level, special insulation against circuits with higher voltage

VEGACAL 63 • 4 … 20 mA/HART - two-wire 17