5.2.3
IRF
The IRF contact functions as an output contact for the self-supervision system of the
protection relay. Under normal operating conditions, the protection relay is energized
and the contact is closed (X100:3-5). When a fault is detected by the self-supervision
system or the auxiliary voltage is disconnected, the contact X100:3-5 drops off and the
contact X100:3-4 closes.
Table 38:
IRF contact
Terminal
Description
X100:3
IRF, common
X100:4
Closed; IRF, or U
aux
disconnected
X100:5
Closed; no IRF, and U
aux
connected
5.3
Protection communication options
Two different protection communication options are available for the protection
relay, that is, a fiber optic link and a galvanic pilot wire link.
Multi-mode or single-mode glass fiber can be used in a fiber optic link. Select the
required glass fiber mode when ordering the protection relay. Link lengths up to 2 km
with multi-mode fiber and link lengths up to 20 km with single-mode fiber can be
achieved. The fiber optic cable used for protection communication is connected to the
X16/LD connector in the protection relay. See the technical manual for more
information.
If a galvanic pilot wire is used as a protection communication link, the pilot wire
modem RPW600 is required. Select the pilot wire option when ordering the protection
relay. The protection communication link always requires two modems in a protection
scheme, thus delivered in pairs of master (RPW600M) and follower (RPW600F)
units. The protection relay is connected to the pilot wire modem using a single-mode
fiber optic cable. Thus a single-mode version of protection relay is required if the pilot
wire link is used. The fiber optic cable is connected to the X16/LD connector in the
protection relay and in Ethernet FX connector in the pilot wire modem.
Setting or configuration is not needed with either of the pilot wire modem variants or
with the protection relay. Pilot wire link lengths up to 8 km with 0.8 mm
2
twisted pair
cables can be applied. Even higher distances can be achieved with good quality
twisted pair cables in the pilot wire link. The achieved link length also depends on the
noise levels in the installations.
The pilot wire modem has QoS LEDs in the front panel for easy diagnostics of the pilot
wire link quality. The diagnostics feature does not depend on the payload over the
pilot wire link and can be used for checking the quality of the intended pilot wire link
even without installing the protection relays. In addition, a diagnostic kit is available
as an ordering option for more advanced diagnostic and logging of diagnostic
Section 5
1MRS758127 C
Protection relay's physical connections
102
RED615
Application Manual