Innotech Device Network Cabling - Manual (Page 24)

© Mass Electronics Pty Ltd 2007
Innotech Device Network Cabling Installation Instructions
Edition 3.0 dated 05.12.2013 Page 24
2-6 Dual Channel Repeaters
For information regarding the conditions when a repeater should be added to the Primary Network please refer to
Chapter 4 of this manual.
NOTE
When a repeater is added to a network it effectively creates two separate networks.
This means users must apply all the rules to each side of the repeater as if they were actually two
completely separate networks. All primary network rules apply without variation.
All repeaters do have Soft Earth features. They do not negate the need for a hard earth on either
side of the repeater network sections. It is not recommended to earth both ports (1 & 2) right at the
repeater as this would defeat some of the advantages of the port isolation. Port 2 (remote port)
should always be earthed on the remote side.
2-6.1 Older Repeaters
The GENII RPTR is the earlier version repeater, easily identified by the fact that it is housed in a square
surface mount enclosure. On these older repeaters Port 1 and Port 2 are isolated from each other;
however Port 1 is internally connected to the main electronic circuits. Due to this; Port 2 is better
isolated and has a higher level of tolerance with respect to comms protection.
It is best to ensure that if there is a long run and the converter is in building A and running to building
B; Port 2 is used to feed Building B. As shown in Figure 9.
The power terminal earth connection is a safety earth because the GENII RPTR is supplied with 240
VAC. This terminal is NOT connected to the Soft Earth terminal located between Comm Ports 1 & 2.
Hazardous Voltage between Earth-Connections
When the Digital Controllers are supplied and earthed from two different switchboards, a hazardous situation
can be created. One earth connection is at the local switchboard and the second earth connection is by way of the
screen of the comms cable. In the event of a fault, there could be full supply voltage difference between the two
earth connections. Always measure the voltage between Port 1 & 2 screens before handling. Use appropriate safety
precautions.
CAUTION
The earth on the RPTR is connected to the soft earth terminal as a requirement.
NOTE
Figure 2-12: Old Style Repeater