7
4 Wiring
diagrams
4.1 Power
supply
The instrument is fitted with a separate power supply with extended operating
range. The power supply terminals are numbered (10) and (11).
Use cables with max cross-section of 2,5 mm
2
.
4.2 Measurement
connections
4.2.1 Voltage connection
Use cables with max cross-section of 2,5 mm
2
and connect them to the terminals marked VOLTAGE INPUT
on the instrument according to the applicable diagrams that follow.
4.2.2 Current connection
It is necessary to use external CTs with a primary rating adequate to the load to be metered and with a 5A
secondary rating. The number of CTs to be used (1, 2 or 3) depends upon the type of network.
Connect the CT output(s) to the terminals marked CURRENT INPUT of the instrument according to the
applicable diagrams that follow.
Use cables with cross-section adequate to the VA rating of the CT and to the distance to be covered. The
max cross-section for the terminals is 2,5 mm
2
.
N.B. The CT secondary must always be in short circuit when not connected to the instrument in order to
avoid damages and risks for the operator.
Warning: THE PHASE RELATIONSHIP AMONG VOLTAGE AND CURRENT SIGNALS MUST BE
CAREFULLY RESPECTED. ALL DISREGARD OF THIS RULE OR OF THE WIRING
DIAGRAM LEADS TO SEVERE MEASUREMENT ERRORS.
