RFL Electronics GARD 8000 - 3.3 CURRENT DIFFERENTIAL SPECIFICATIONS

Technical Data
GARD 8000 SYS RFL Electronics
September 24, 2012 3-5 973.334.3100
Table 3-1. Fiber data
Wavelength and
emitter type
Fiber type
Connector type
System gain
Typical distance
(3dB margin)
ANSI C37.94
Multimode
ST
21 dB
2km/1.2 miles
1300 nm LED
Single mode
ST
22 dB
29km/18 miles
1300 nm Laser
Single mode
ST
39 dB
59 km/37 miles
1550 nm Laser
Single mode
ST
36 dB
102 km/63 miles
3.3 CURRENT DIFFERENTIAL SPECIFICATIONS
3.3.1 ANALOG CURRENT INPUTS
Thermal Withstand Capability:
Continuous: 20A
RMS
One second: 250A
RMS
Current Circuit Burden:
< 0.1 VA @ 5A
< 0.02 VA @ 1A
3.3.2 METERING DATA
The metering data is presented in units of primary A
RMS
and is an integer number.
Accuracy: 3% or 0.01A multiplied by the CT ratio, whichever is greater.
3.3.3 OSCILLOGRAPHY DATA
Oscillography data is reported in IEEE COMTRADE 1999 format.
Sample rate: (33 samples per cycle)
60Hz: 1980 samples per second
50Hz: 1650 samples per second
Range: ±200A
PEAK
(referenced to the secondary of the CT)
Accuracy: 3% or 0.03A, whichever is greater (referenced to the secondary of the CT).
3.3.4 STATUS BIT OPERATING TIME
Transmission time: 6 – 24 ms (average = 16 ms, CRC protected).
3.3.5 DIRECT TRANSFER TRIP
Back-to-back channel time of 3ms, as measured to a solid state output.