Beckhoff EL34 Series - Power Measurement in a Single-Phase Mains Network with Ohmic Consumers

Application examples
EL34xx264 Version: 1.5
7.3 Power measurement in a single-phase mains network
with ohmic consumers
• The voltage is measured via connections L1, L2, L3 and N.
• The current is measured via three current transformers [}29] and the connections I
L1
, I
L2
, I
L3
and I
N
(star
point of the current transformers).
WARNING
WARNING: Risk of electric shock!
Bring the Bus Terminal system into a safe, voltage-free state before starting mounting, disassembly or
wiring of the Bus Terminals!
NOTE
Attention! Risk of device damage!
Avoid confusing the current and voltage circuit during connection, since the direct connection of mains volt-
age to the terminal points for the current transformers (typical input resistance 220mΩ) would destroy the
power measurement terminal!
Fig.165: Power measurement at ohmic consumers