GE Multilin g60

GE Multilin G60 Generator Protection System 3-27
3 HARDWARE 3.2 WIRING
3
3.2.10 IRIG-B
IRIG-B is a standard time code format that allows stamping of events to be synchronized among connected devices within
1 millisecond. The IRIG time code formats are serial, width-modulated codes which can be either DC level shifted or ampli-
tude modulated (AM). Third party equipment is available for generating the IRIG-B signal; this equipment may use a GPS
satellite system to obtain the time reference so that devices at different geographic locations can also be synchronized.
Figure 3–27: IRIG-B CONNECTION
The IRIG-B repeater provides an amplified DC-shift IRIG-B signal to other equipment. By using one IRIG-B serial connec-
tion, several UR-series relays can be synchronized. The IRIG-B repeater has a bypass function to maintain the time signal
even when a relay in the series is powered down.
Figure 3–28: IRIG-B REPEATER
Using an amplitude modulated receiver will cause errors up to 1 ms in event time-stamping.
Using an amplitude modulated receiver will also cause errors of up to 1 ms in metered synchrophasor values.
Using the IRIG-B repeater function in conjunction with synchrophasors is not recommended, as the repeater adds
a 40 s delay to the IRIG-B signal. This results in a 1° error for each consecutive device in the string as reported in
synchrophasors.
RELAY
BNC (IN)
RECEIVER
RG58/59 COAXIAL CABLE
GPS SATELLITE SYSTEM
GPS CONNECTION
OPTIONAL
IRIG-B(-)
4A
+
-
827756A5.CDR
IRIG-B
TIME CODE
GENERATOR
(DC SHIFT OR
AMPLITUDE MODULATED
SIGNAL CAN BE USED)
4B
IRIG-B(+)
BNC (OUT)
REPEATER
TO OTHER DEVICES
(DC-SHIFT ONLY)
NOTE
NOTE