PACSystems RX3i - Terminal Assembly Frame Ground Connection; Wiring Diagrams

User Manual Chapter 2
GFK-2749A Jan 2020
Installation 26
Although Grid 1 and Grid 2 are interchangeable, you should connect the most stable source
to Grid 1. Between a utility grid and a generator, the utility grid is the best choice for
connection to the PSM Grid 1 inputs. This will yield the most accuracy and the least reading-
to-reading fluctuation.
Requirements for Terminal Assembly Connections
Terminal Assembly connections above 600VAC required prepared wire ends, such as
tinning of the conductors, or use of crimpled or soldered forked connectors or ferrules.
Terminal connections for COM1, COM2, voltage sensing and current sensing terminals
Terminal torque: 1.81 Nm (16 in-lb)
Wiring size/type: 0.823 mm
2
– 5.26 mm
2
(18–10 AWG) solid/stranded
Relay output terminal connections
Terminal torque: 0.8 Nm (7 in-lb)
Wiring size/type: 0.205 mm
2
– 0.410 mm
2
(30–12 AWG) solid/stranded
WARNING
Potential transformers MUST be used for voltage isolation and scaling purposes. Current
Transformers must be used for all current measurements. Please refer to the following
diagrams.
2.6.2 Terminal Assembly Frame Ground Connection
The basic system configuration consists of the host controller, the PSM and the Terminal
Assembly. Interface cables are used to connect the PSM to the Terminal Assembly. The
Terminal Assembly must have frame ground connected to ensure that the metal case on
the Terminal Assembly is safely at ground potential. In the diagrams following, specific
wiring configurations are detailed. Make sure that the safety features detailed in the
drawings are included in your installation. Failure to do so could result in personal injury or
death and equipment damage.
2.6.3 Wiring Diagrams
WARNING
Be sure you read and understand all safety-related information in this manual before
attempting to wire or use the PSM.
Connections for 120/240 VAC system with CTs 27
Connection to Three-Phase Four-Wire WYE System with Three PTs 28
Configuration for Three-Wire Delta system with Two PTs (Two Wattmeter
Method) for Load Monitoring 29