16
Instruction Leaflet
I. L. 29-889B
Effective June 2011
Instructions for Digitrip RMS 910 Trip Unit
eaton corporation
www.eaton.com
sensor rating, the Trip Unit will trip the breaker again .
As indicated in Figures 2 and 9, a back-up battery is provided to
maintain the mode of trip LED indication in the Digitrip RMS 910 Trip
Unit when external control power to the Power / Relay module is not
available . The back-up battery is located in the rating plug along with
a battery check push-button and a green battery check LED . The bat-
tery in the rating plug is "OK" if the LED lights "Green" when the "bat-
tery check" button next to it is pushed (see Section 4 .5) .
otee:
N
The battery is used only to maintain the cause of TRIP LED indication .
It has NO part in the PROTECTION FUNCTION of the Trip Unit, and, it does
NOT light the display window .
1.4 Power / Relay Module
The Power / Relay Module (PRM) (see Figure 10) is separate from
the RMS Digitrip 910 Trip Unit itself, and is
not required
for the Trip
Unit to perform its
protection functions
. The Power / Relay Module
performs two functions . First, it uses available external control
power (120 V 50/60 Hz ac, 6 VA) to operate the display window, com-
munications circuitry, and reason for trip LED indicators . Second,
it provides relay contacts for use by other devices remote from the
circuit breaker .
NOTICE
THE POWER / RELAY MODULE HAS 120 V 50/60 HZ AC INPUT AS STANDARD
FOR ALL BREAKER TYPES. THERE IS AVAILABLE FOR CERTAIN BREAKER
TYPES A 230 V 50/60 INPUT VOLTAGE RATING. BEFORE ENERGIZING
THIS CONTROL VOLTAGE, PLEASE VERIFY CORRECT VOLTAGE RATING IS
EMPLOYED. THE DISPLAY, COMMUNICATION, OR TRIP RELAY ALARMS
MAY BE ERRATIC OR NONFUNCTIONAL IF WRONG VOLTAGE IS USED.
Figure 13. Long Delay Current Settings.
The relays operate when the Trip Unit detects the following condi-
tions, as shown in Figure 2:
•
Short-Circuit Trip Alarm
•
High Load Alarm
•
Long Delay Trip Alarm
•
Ground fault Trip Alarm (types LIG, LSG, LSIG) or Neutral Over-
Current Alarm (types LI, LS LSI)
•
In addition, the Power / Relay Module also contains the INCOM®
COMMUNICATIONS CLOSE contact, which operates the circuit
breaker's closing release, on command from INCOM / IMPACC®
(see Section 5 .8 .) .
Each relay contact is rated for 120 V, 50/60 Hz ac, 1 .0 Ampere . The
High Load Alarm contact operates after the load current has exceed-
ed 85% of the long delay current setting,
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for 40 seconds . The
40-second delay allows the system to "ride through" momentary high
load conditions and avoid nuisance alarms .
Long Delay
Available Settings
Setting
.5, ,6, .7, .8,
.85, .9, .95, 1
In Multiples of
Rating Plug
Amperes
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The Long Delay Trip Alarm contact operates after the breaker TRIPS
due to over-load conditions which exceeded the Long Delay Trip set-
tings .
For Type LSG, LIG, and LSIG Trip Units, the Ground Fault Trip Alarm
contact operates after the breaker TRIPS due to conditions which
exceed the Ground Fault protection settings . For Type LS, LI, and
LSI Trip Units, the Neutral Current Alarm contact operates when the
neutral current exceeds the Long Delay Current protection setting,
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.
Figure 14. Long Delay Time Settings.
Figure 15. Short Delay Current Settings.
The Short-Circuit Trip Alarm contact operates after the breaker TRIPS
due to an INSTantaneous trip, Short-Delay Trip, DlSCriminator trip, a
Fixed Instantaneous OverRlDe trip, or a Rating PLUG trip as appli-
cable .
Even without available external control power, once the load cur-
rent through the circuit breaker exceeds approximately 20% (40%
if single phase) 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, and all protection functions are
functioning . However, the display window will remain dark .
otee:
N
If 120 VAC control power is lost to the Power / Relay Module, the
LOCKOUT after trip will reset and the breaker can be closed again . However
the cause of trip bit will remain set in the Digitrip's non-volatile memory and a
cause of trip message will reappear when control power returns . A complete
clearing of cause of trip history may be accomplished by depressing the reset
push-button when the Digitrip unit is powered up (indicated by the Unit Status
flashing) .
1.5 Potential Transformer Module
The Potential Transformer Module (PTM) (see Figure 11) is also
separate from the RMS 910 Trip Unit and is not required for the Trip
Unit to perform its protection functions . The Potential Transformer
Module provides three-phase primary voltage information necessary
for the Trip Unit to calculate power and energy values (see Figure 2) .
.
,
,
Available Settings
12, 15, 20, 24
I...
Seconds at
6 Times
,
.
. .
.
.
6
x
Long
Time
Delay
Sec.
at 6 x
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Long Delay Setting
2, 4, 7, 10,
. .
S1 and S2
2, 2.5, 3, 4
Available Settings
. .
.
Setting
In Multiples of
Long Delay Setting
Values are Specified on Rating Plug
5, 6, S , S
1
2
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