Bender RCMA420-D-2 B74043002 Hoja De Datos

9

 

AC/DC sensitive residual current monitor Type B according to IEC 
62020 and IEC 60755

 

Two separately adjustable response ranges (prewarning, alarm)

 

Adjustable switching hysteresis 

 

r.m.s. value measurement 

 

Starting delay, response delay and delay on release

 

Measured value display via multi-functional LC display

 

Alarm indication via LEDs (AL1, AL2) and changeover contacts (K1, K2)

 

N/C operation or N/O operation selectable

 

Password protection against unauthorized parameter changing

 

Fault memory function can be switched off

 

CT connection monitoring

Once the supply voltage U

s

 is applied, the starting delay is activated. Meas-

ured 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 W20AB…W60AB series. The currently 
measured value is shown on the LC display. In this way any changes, for exam-
ple when circuits are connected to the system, can be recognized easily. If the 
measured value exceeds one or both response values, the response delays 
t

on1/2

 start running. Once the response delay t

on1/2

 has elapsed, the K1/K2 

alarm relays switch and the alarm LEDs AL1/AL2 light up. If the residual cur-
rent falls below the release value (response value minus hysteresis), the delay 
on release t

off

 begins. Once the release delay t

off

 has elapsed, the alarm relays 

return to their original state 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.