Et system LAB-HP/E 10KW, Manual

Page: 36 / 41

Sense Mode
30 ET System electronic GmbH
GENERAL INFORMATION FOR SENSING
The sensing line moves the measuring point of the output voltage measurement to the load. The voltage
measurement is carried out with a differential amplifier, the last resistor in the chain being "short-circuited" with a
low-resistance parallel resistor. When the sensing line is opened, the output voltage increases between 1% and 2% of
the nominal voltage, depending on the model. The displayed voltage on the display does not change. When the Sens is
connected to the load, the power resistor is mathematically transformed into the device, resulting in a residual error
of up to 0.5% depending on the load line used. More detailed information can be obtained from the manufacturer.
WARNING INSTRUCTIONS FOR USING RELAYS TO THE LOAD DRAFT
In an application where the load is for example should be dropped with a relay and the Sens is used at the same time,
care must be taken to ensure that the load current can not flow through the sensing lines as this can lead to the
destruction of the sensor. This is shown schematically in the following figure.
The circuit breaker (S_power) must be closed when starting before the Sens (S_sens). When switching off, the Sens
must first be opened and then the circuit breaker can be opened. Otherwise, a current flow may occur across the
sensing line, and this may be particularly critical when disconnecting.