Description
2.8 Electronic trip unit ETU
3VA27 molded case circuit breakers & 3WL10 air circuit breakers
82
Manual, 10/2018, L1V30499596002-01
Measured values of the ETUs of the 3-series
Maintenance displays
Parameter
Information on the last 30 trips
Type of protection function, fault values, and time stamp
Information on the last 200 events
Type of event, time stamp
Number of mechanical switching operati-
ons
1)
No.
Can be assigned to alarm
Total number of trips
No.
—
Operating hours counter
h
—
Contact wear
%
Pre-alarm > 80%
Alarm = 100%
Date of maintenance performed
Last
Direction to perform necessary mainte-
nance
––
Key data
Type of circuit breaker, name assigned to the device, serial number
Self-diagnostics
Parameter
Precision
Open-circuit detection
Watchdog: constant CT monitoring, moni-
toring of the electronics and tripping coil
Alarm due to dis-
connection Current
transformer, rating
plug, tripping coil
Optional: Only alarm or tripping of the circuit
breaker
Temperature (T)
Pre-alarm and alarm
due to overheating
1)
If auxiliary power supply is connected
Metering functions of the ETUs of the 6-series
The electronic trip units of the 6-series can be expanded with the metering functions
MF Basic or MF Advanced. These measure the voltage between the phases with internal
voltage tap - optionally on the incoming or outgoing feeder side, i.e. internally before or after
the contact interruption point - and can therefore calculate and transmit values for power,
energy, phase difference, etc., taking the current signals into consideration.
●
MF Basic provides many measured values in accordance with IEC 61557-12
●
MF Advanced provides not only the measured values described but also many enhanced
protection functions, which are listed in Chapter Parameters of the trip units (Page 72). In
this way, the ETU can also power the metering module MF Advanced directly from the
busbar itself if no auxiliary power supply is provided via the Breaker Connect module.
Faults such as overvoltages in the power system can therefore be detected before the
contacts of the circuit breaker are closed.