4
Instruction Leaflet
I. L. 29-885D
Effective August 2011
Instructions for Digitrip RMS 510 Trip Unit
EATON CORPORATION
www.eaton.com
In the Digitrip RMS 510 Trip Unit, all required sensing and tripping
power to operate its protection function is derived from the current
sensors in the circuit breaker . The secondary currents from these
sensors provide the correct input information for the protector func-
tions, as well as tripping power, whenever the circuit breaker is
carrying current . These signals develop analog voltages across the
appropriate sensing resistors including:
1 .
Phase currents;
2 .
Ground current or Neutral current (when supplied); and
3 .
Rating plug .
The resulting analog voltages are digitized by the custom designed
integrated circuits . The micro-computer, in cyclic fashion, repeatedly
scans the voltage values across each sensing resistor and enters
these values into its Random Access Memory (RAM) . The data
used to calculate true RMS current values, which are then repeat-
edly compared with the protection function settings and other oper-
ating data stored in the memory . The software program then deter-
mines whether to initiate protection functions, including tripping the
breaker through the low energy trip device (Flux Transfer Shunt Trip
or Direct Trip Actuator) in the circuit breaker .
Figure 1.
Figure 2. Digitrip RMS 510 Trip Unit Type LSIG with Rating Plug.
Catalog Number
LED's light "Red"
to indicate cause
of trip
Time-Current
Curve for Ground
Protection
SPB Rating Plug
View Settings in
Window
Adjust Protection Settings
for Desired Values with
Rotary Switches
Trip Unit Operation Status
"Blinking Green"=OK (See
Section 1 .1 .1)
R-Frame Rating Plug
Press and Release "Trip
Reset" Push Button to
Reset Trip Unit
Press and Release "Test"
Push Button to Initiate
Self-Test (See Section 4)
Keyed
Receptacle
for Auxiliary
Power Module
Connector (See
Section 1 .3)
Time-Current curve for
Phase Protection
DS Rating Plug
1.1.1 Operational Status and Protection TRIP Indicators
The "Green" Light Emitting Diode (LED) in the lower right corner of
the Trip Unit (Figure 2) "blinks" once each second to indicate the Trip
Unit is operating normally . Once the load current through the circuit
breaker exceeds approximately 10% of the frame/current sensor
rating, the green LED will flash "On" and "Off" once each second, to
indicate the trip unit is energized and operating properly .
otee:
N
If the LED is steadily "GREEN", i .e . not blinking, the Trip Unit is not
ready .
The LEDs, shown in Figures 2 and 3 thru 8 on the face of the Trip
Unit, light "RED" to indicate the reason for any automatic trip opera-
tion . As indicated in Figures 3 thru 8, each LED is strategically locat-
ed in the related segment of the time-current curve depicted on the
face of the Trip Unit . The reason for trip is identified by the segment
of the time-current curve where the LED is lit "RED" . Following an
automatic protection trip operation, the back-up battery continues to
supply power to LED's as indicated in Figures 2 and 9 . The Digitrip
can be RESET by:
•
Pressing and releasing the "
TRIP RESET
" button (See Figure 2
lower right corner just above the "
UNIT STATUS
" LED);
