Power measurement at a machine
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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! |
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Attention! Risk of device damage! Avoid confusing the current and voltage circuit during connection, since the direct connection of mains voltage to the terminal points for the current transformers (typical input resistance 100 mΩ) would destroy the power measurement terminal! |
EL3443
- The voltage is measured via connections L1, L2, L3 and N.
- The current is measured via three current transformers (e.g. from the Beckhoff SCT series) and the connections IL1, IL2, IL3 and IN (star point of the current transformers).
 | Fuse protection of the terminal The voltage measurement inputs L1 - L3 are high-impedance; a minimum measurement current flows. The fuses to the connection points L1 - L3 are therefore only to be designed according to the connection cross-section. For the current measurement inputs IL1 – IL2, the fuse protection must be adapted according to the device to be measured. |
| **) PE as star point for 3-phase systems without neutral line Depending on the current transformers used, PE must be connected as star point in 3-phase systems without neutral line as shown in Fig. “EL3443, power measurement at a machine ". Observe the regulations of the manufacturer of the current transformers! |
| Negative power values If negative power values are measured on a circuit, please check whether the associated current transformer circuit is connected correctly. |
EL3453
- The voltage is measured via connections L1, L2, L3 and N.
- The current is measured via 4 current transformers (e.g. from the Beckhoff SCT series) and the connections IL1, IL2, IL3 and IN (star point of the current transformers).
| Negative power values If negative power values are measured on a circuit, please check whether the associated current transformer circuit is connected correctly. |