IL04915001E
Effective 7/09
7
Ground fault circuit (cont’d)
S/C Trip Level
Current wave shape
External CT
Sine
125 A ac
IEC 60755 DC 0
°
110 A rms
IEC 60755 DC 90
°
80 A rms
IEC 60755 DC 135
°
60 A rms
Accuracy of S/C trip Point
±
(10% + 2A)
S/C Trip Delay
5
±
2 ms
Type 2 Co-ordination on S/C
Selectable on / off with 0.02 and 0.3 s G/F Trip Delay
settings
Thermal withstand capability (external CT)
300 A
infinitely
500 A
2000 ms
1000 A 500 ms
2000 A 125 ms
5000 A 20 ms
Suitable external CT types – Must have
internal electronics to provide short circuit/
open circuit detection
5
C311CT1-A2
46 mm (1.81”) inner diameter
C311CT2-A2
90 mm (3.54”) inner diameter
C311CT3-A2
150 x 170 mm (5.9 x 6.7”) Split core
C311CT4-A2
100 x 350 mm (3.94 x 13.78”) Split core
C311CT5-A2
145 mm (5.70”) inner diameter
C311CT6-A2
240 mm (9.45”) inner diameter
C311CT7-A2
300 x 300 mm (11.8 x 11.8”) Split core
C311CT8-A2
28 mm (1.1”) inner diameter
C311CT9-A2
65 mm (2.56”) inner diameter
C311CT28-A2 28 mm (1.1”) inner diameter
External CT Supervision circuit
CT loop resistance causing a fault (O/C)
> 1 k
Ω
CT shunt resistance causing a fault (S/C)
< 50
Ω
CT Fault Trip Delay
1.5 s
Relay contacts
Configuration
Voltage free form “Z” (1 N.O. and 1 N.C contact, 4
terminals)
Maximum UL/CSA rating
5 A @ 125 and 250 V AC, general use
1/6 hp, 125 and 250 V AC
5 A @ 30 V DC, resistive
B300:
30 A, 3600 VA make, 3 A 360 VA break @ 120 V AC
15 A, 3600 VA make, 1.5 A 360 VA break @ 240 V AC
EN 60947 rating
5 A @ 250 V ac, utilization category AC-12
4 A @ 250 V ac, utilization category AC-13
3 A @ 250 V ac, utilization category AC-14
3 A @ 250 V ac, utilization category AC-15
5 A @ 30 V dc, utilization category DC-12
3 A @ 24 V dc, utilization category DC-13
Isolation voltage
2 kV rms, 50 – 60 Hz, 1 minute
Breakdown voltage between open contacts
1 kV rms
Maximum fusing under EN 60947-5-1
13 A
5
Future production of all Eaton C311CT Series 500:1 ratio CTs will be supplied with internal electronics to
provide short circuit/open circuit detection by the D64RPB30 relay. These are designated Series A2, as shown
above. They will work with all D64R relays suitable for 500:1 ratio CTs.
