1.4 UR HARDWARE
1 GETTING STARTED
1.4.1 MOUNTING AND WIRING
Please refer to Chapter 3: Hardware for detailed mounting and wiring instructions. Review all WARNINGS and CAUTIONS
The EnerVista UR Setup software communicates to the relay via the faceplate RS232 port or the rear panel RS485 / Ether-
net ports. To communicate via the faceplate RS232 port, a standard straight-through serial cable is used. The DB-9 male
end is connected to the relay and the DB-9 or DB-25 female end is connected to the PC COM1 or COM2 port as described
in the CPU communications ports section of chapter 3.
Figure 1–7: RELAY COMMUNICATIONS OPTIONS
To communicate through the L90 rear RS485 port from a PC RS232 port, the GE Multilin RS232/RS485 converter box is
required. This device (catalog number F485) connects to the computer using a "straight-through" serial cable. A shielded
twisted-pair (20, 22, or 24 AWG) connects the F485 converter to the L90 rear communications port. The converter terminals
(+, –, GND) are connected to the L90 communication module (+, –, COM) terminals. Refer to the CPU communications
ports section in chapter 3 for option details. The line should be terminated with an R-C network (that is, 120 Ω, 1 nF) as
described in the chapter 3.
1.4.3 FACEPLATE DISPLAY
All messages are displayed on a 2 × 20 backlit liquid crystal display (LCD) to make them visible under poor lighting condi-
tions. Messages are descriptive and should not require the aid of an instruction manual for deciphering. While the keypad
and display are not actively being used, the display will default to user-defined messages. Any high priority event driven
message will automatically override the default message and appear on the display.
L90 Line Current Differential System