Instruction Book
Effective: May 2016
Page 45
IB131017EN
For more information visit:
www.Eaton.com
5-5 ELECTRONIC TRIPPING SYSTEM
VCP-TL and VCP-TRL circuit breakers can utilize an
optional
three part tripping system:
Microprocessor-based trip unit
Current Sensors
Trip Actuator
For detailed information pertaining to the different trip unit
models available with these circuit breakers, refer to the
specific instruction leaflet dedicated to the trip units.
5-5.1 MICROPROCESSOR-BASED TRIP UNIT
VCP-TL and VCP-TRL circuit breakers can use either of
two Digitrip RMS trip units whose main features are
summarized in Table
5.1
. The two models (Model 520V
and Model 1150V) are not interchangeable in the field.
Contact EATON for upgrading to Model 520V or Model
1150V.
The electronic trip units are self-powered. When the
circuit breaker is closed, no external power is required to
operate their protective systems. Current signal levels
and the control power are derived from the current
sensors mounted behind the cassette.
Figure 5-18 Digitrip RMS 1150V Programmable Trip
Unit Installed in Typical Circuit Breaker
Table 5.1 Digitrip Trip Units
Functions
520V
1150V
LSIG Protection
Yes
Yes
Disable (I)
Yes
Yes
GF Protection
Yes
Yes
GF Alarm
No
Yes
Display
No
Yes
Programmable
No
Yes
Metering
No
Yes
Power and
Energy Values
No
Yes
Power Quality
No
Yes
Communication
No
Yes
Three-line, (eight characters per line) LED display.
Available control voltages are 24/48Vdc, 12OVac and 24OVac
A functional local test can be performed through the trip
unit's test receptacle (Figure
5-18
). A small hand held
functional Test Kit is used to check circuitry and
mechanical tripping functions (Figure
5-19
).
When the circuit breaker is shipped from the factory, the
trip unit's protective functions are normally set at mini-
mum values. For specific overload tripping characteristics
and time/current curves to coordinate with a load or
system, refer to the trip unit instruction book.
Figure 5-19 Hand Held Tester
