Once the supply voltage US is applied, the start-up delay is activated. Measured values
changing during this time do not influence the switching state of the alarm relays.
Residual current measurement takes place via an external measuring current transformer
of the CTUB100 series.
Once the supply voltage US is applied, the start-up delay is activated. Measured values
changing during this time do not influence the switching state of the alarm relays.
Residual current measurement takes place via an external measuring current transformer
of the CTUB100 series. The currently measured value is shown on the LC display. In this
way any changes, for example when circuits are connected to the system, can be recognised
easily. If the measured value exceeds the set response values, the response delays
ton1/2 begin. Once the response delay ton1/2 has elapsed, the K1/K2 alarm relays switch
and the alarm LEDs AL1/AL2 light up. If the current falls below the release value (response
value plus hysteresis), the release delay toff. When toff has elapsed, the alarm relays
return to their initial position and the alarm LEDs AL1/AL2 go out. If the fault memory
is activated, the alarm relays remain in the alarm state and the LEDs light until the reset
button is pressed or until the supply voltage is interrupted. The device function can be
tested using the test button. Parameters are assigned to the device via the LCD and the
control buttons on the front panel; this function can be password-protected.
The function of the device and the CT connections are continuously monitored. In the event
of a fault, the alarm relays K1/K2 switch without delay, the alarm LEDs AL1/AL2/ON flash.
On removal of the fault, the alarm relays return to their initial position either automatically
or by pressing the reset button.
• AC/DC sensitive residual current monitoring in earthed two, three or four conductor
systems (TN and TT systems)
• Monitoring of variable-speed drives, UPS systems, construction site equipment, printing
machines, battery systems, laboratory equipment, wood working machines, MF welding
systems, furniture industry, medical electrical equipment, etc.
• AC/DC sensitive current monitoring of, in the normal case, de-energised single conductors
(e.g. N and PE conductors)
