
30
Operating Manual for Series NRX
Trip Units - Digitrip™ 520/520M
EATON
www.eaton.com
Instruction Leaflet
IL01301051E
effective September 2013
Symptom
Probable Cause
Possible Solution(s)
References
Circuit breaker tripping and orange
LED (not red) illuminated above
SHORT text or above alarm text (LI
style)
Circuit breaker MCR (b) auxiliary switch not
indicating proper state
Check MCR (b) switch
Refer to Appendix E or F master
connection diagram
Circuit breaker mechanism not closing properly
Check with factory
Refer to Section 2 for diagnostics
Maintenance Mode
will not shut off
Verify remote switch or
local switch is not on
Maintenance mode was
initially enabled by
communication and is not
available
Restore communication link if possible and
check for possible wiring errors.
Appendix C: Specifications
Protection
Trip Pickup
Trip Time
Trip Pickup Tolerance
Trip Time Tolerance
LONG
I
2
t
I
R
= 0.5, 0.6, 0.7, 0.75, 0.8, 0.9, 0.95, 1.0 x I
n
2, 4 ,7, 10, 12, 15, 20, 24 at 6 x I
R
110% ±10% x I
R
+ 0, –30%
SHORT
FLAT
2, 3, 4, 5, 6, 7, 8, 10 x I
R
0.1, 0.2, 0.3, 0.4, 0.5
±10%
Per curve
SHORT
I
2
t
2, 3, 4, 5, 6, 7, 8, 10 x I
R
0.1*, 0.3*,0.5* at 8 x I
R
±10%
Per curve
INST
2, 3, 4, 6, 8, 10, 12, OFF x I
n
OFF N/A on LI style
≤ 50 ms
±10%
Per curve
GROUND
FLAT
0.25, 0.3, 0.35, 0.4, .05, 0.6, 0.75, 1 x I
n
0.1, 0.2, 0.3, 0.4, 0.5
±10%
Per curve
GROUND
I
2
t
0.25, 0.3, 0.35, 0.4, .05, 0.6, 0.75, 1 x I
n
0.1*, 0.3*, 0.5* at 0.625 x I
n
±10%
Per curve
MCR
Automatically defined by the breaker type
≤ 30 ms
HIGH INST
Automatically defined by
breaker type
≤ 30 ms
Frequency
50, 60 Hz
Temperature range of circuit breaker
-20°C to 55°C
Temperature trip of PC board
85°C
Relative humidity (noncondensing)
0 to 85%
Metering accuracy
+- 3% x NF Max Frame Rating (1600A), +-4% RF Max Frame Rating (4000A)
Control voltage consumption
6 watts
Control voltage (if desired for Digitrip 520M
alarm relays)
24 Vdc ±10%
Alarm Relays (Resistive Load)
AC
0.5A
@ 230 Vac
AC
1A
@ 120 Vac
DC
1A
@ 48 Vdc
DC
0.35A
@ 125 Vdc