4
• Where used, a device’s GND or EARTH link must be removed (if fitted).
Note:
Challenger
Plus
panels do not have a GND link.
• Where 240/16 VAC plug packs are used, connect the earth conductor to the
device’s power earth terminal (similar to Figure 5 on page 11, item 3).
• Connect one end only of the RS-485 data cable shield to a device’s LAN
earth terminal or earth lug (similar to Figure 5 on page 11, item 1).
• Connections to building earth via CET are no longer required.
Note:
For new installations the earthing and configuration instructions in this
manual supersede all previously-released installation instructions supplied with
other devices (unless otherwise noted).
RS-485 LAN cabling
The cabling requirements for an RS-485 system LAN are:
• Use 2-pair twisted shielded data cable such as Belden 8723.
• In each segment of LAN cabling, connect one end only of the data cable
shield to a d
evice’s LAN earth terminal. Join data cable shields where cable
extends past a device that doesn’t have a LAN earth connection.
• The length of the LAN cable run should not exceed 1.5 km, unless LAN
isolation devices are used to extend the distance.
Power supply to RS-485 LAN devices
Devices on the
LAN may be supplied from the panel’s or DGP’s + and – LAN
power terminals. Use an external 12 V power supply (such as TS0073 2 A Power
Supply) when:
• The device is more than 100 m (data cable length) from the panel
• Electrical isolation is required
• More power is needed than can be provided by the LANs
When powering a LAN device from an external 12 V power supply:
• Connect the external power supply’s ‘+’ terminal to the device’s ‘+’ terminal.
Do not connect the power to the LAN +.
• Connect the external power supply’s ‘-’ terminal to the device ‘-’ terminal.
• Connect the LAN cable black wire ‘-’ to the device ‘-’ terminal.
