26
Instruction Leaflet
I. L. 29-888B
Effective July 2011
Instructions for Digitrip RMS 810 Trip Unit
eaton corporation
www.eaton.com
5.7 System Power Factor (Remote)
The Digitrip RMS 810 can send the present value of the system
power factor to a remote terminal even though system power fac-
tor is not available for local display in the Trip Unit window The range
assumptions and accuracy for the system power factor function
values are:
Range -
From -0 .5 (lagging) to +0 .5 (leading)
Assumes -
Balanced three-phase load, per ANSI Std . C 12 .1
Current -
> 20% of Frame Rating for Series C® R-Frame or
Type SPB circuit
breakers .
Current -
> 20% of [Current] Sensor Rating for Type DS cir
cuit breakers .
Accuracy -
± 0 .02
5.8 Remote Closing and Tripping of Circuit Breakers
The Digitrip RMS 810 Trip Unit can respond to commands from the
remote master computer to "TRIP" the circuit breaker remotely;
and furthermore, if the circuit breaker has been equipped with the
applicable optional electrical operator or spring release feature,
the Digitrip RMS 810 Trip Unit can respond to commands from the
remote master computer to "CLOSE" the circuit breaker remotely .
The CLOSE command causes the "Communications Close" contact
in the Power Relay Module to close (see wires CC1 and CC2 in
Figure 2), making the circuit breaker's closing control circuit, and
releasing it to close (see the connection diagram applicable for your
circuit breaker listed in Section 6) .
When the Electrical Operator or Spring Release option is purchased
for the circuit breaker, the Communications Close contact is wired
into the close release circuit at the factory . The TRIP command
causes the Digitrip RMS 810 Trip Unit to operate the circuit breaker's
trip release (see "
T
" in Figure 2) . The trip release remains locked-
out, so that the circuit breaker cannot be reclosed, until the Trip Unit
is reset (see Section 5 .9) . The Trip Unit displays "EXTT" in its window
and sends back the "EXTT message over INCOM to the remote
master computer . (Note that the values of the currents through the
circuit breaker will be "zero" when it is OPEN .)
WARNING
UNEXPECTED SIGNALS TO "CLOSE' OR "TRIP' A CIRCUIT BREAKER FROM
A REMOTE LOCATION BY THE COMMUNICATIONS NETWORK CAN CAUSE
PERSONAL INJURY TO MAINTENANCE PERSONNEL WORKING IN THE
IMMEDIATE VICINITY OF THE CIRCUIT BREAKER. PROVIDE PERMISSIVE
CONTROL SWITCHES, OR OTHER MEANS, LOCALLY AT THE CIRCUIT
BREAKER FOR MAINTENANCE PERSONNEL TO USE IN CONTROLLING
REMOTE "CLOSE" OR "TRIP" SIGNALS. FOR DETAILED INFORMATION
CONCERNING THE BREAKER CONTROL CIRCUITS NECESSARY TO
IMPLEMENT PERMISSIVE CONTROL LOCALLY, REFER TO THE CIRCUIT
BREAKER CONNECTION DIAGRAMS LISTED IN SECTION 6.
5.9 Remote Resetting of the Trip Unit
NOTICE
BEFORE RESETTING TRIP UNIT, BE SURE TO:
• RECORD DISPLAY VALUES OF ALL PERTINENT PARAMETERS.
• NOTE WHICH CAUSE OF TRIP LEDS ARE LIGHTED "RED”.
• CORRECT THE CAUSE OF THE OVERCURRENT OR FAULT CONDITION
THAT CAUSED THE BREAKER TO TRIP.
BECAUSE THE AUTOMATIC LOCKOUT-AFTER-TRIP FEATURE OF THE
DIGITRIP RMS 810 TRIP UNIT MAINTAINS THE CIRCUIT BREAKER IN A
"TRIP-FREE" CONDITION. THE TRIP UNIT MUST BE RESET AFTER EACH
TRIP OPERATION (WHETHER INITIATED BY OVER-CURRENT CONDITIONS
OR BY REMOTE INCOM
®
/ IMPACC
®
SIGNAL), BEFORE THE BREAKER CAN
BE CLOSED AGAIN. THE RESET CAN BE ACCOMPLISHED EITHER LOCALLY
BY PRESSING AND RELEASING THE "TRIP RESET" PUSH BUTTON (SEE
FIGURE 1), OR REMOTELY BY THE IMPACC
®
SYSTEM.
Although the reset can be accomplished locally by pressing and
releasing the "TRIP RESET push button (see Figure 1), it is some-
times inconvenient or untimely to go to the circuit breaker in order
to reset the Trip Unit . For such cases where the circuit breaker is
far from the plant control room, the IMPACC
®
system provides the
User with a means for resetting the circuit breaker through the com-
munications network "Trip Unit Reset" command . Executing the Trip
Unit Reset command remotely from the master computer by the
INCOM
®
/ lMPACC
®
system is exactly equivalent to pressing and
releasing the "Trip Reset" push-button on the front of the Trip Unit .
In addition to the Trip Unit Reset capability, the INCOM
®
/ IMPACC
®
communications capability of the Trip Unit provides the User with a
means for resetting several parameter values stored in the Trip Unit's
memory . Using the proper commands, the User can view and reset
the following trip event buffer parameters remotely: time of trip, val-
ues of phase and ground currents, number of electronically initiated
trip operations, peak [power] demand, energy, and the cause of trip .
