TWINFLEX
®
SRP Remote Status Indicator Engineering and Commissioning Manual
12
Installation and Commissioning
Topology & Cabling
All system wiring should be installed to comply with BS 5839: Pt 1: 2002 and BS 7671 (wiring
regulations) and any other standards relevant to the area or type of installation. A cable complying with
BS 5839: Pt 1: 2002 Category 1 (cable required to operate for prolonged periods during fire conditions)
is required. This must be a 2-core 1.5mm
2
screened fire resistant cable (i.e. MICC, FP200, Firetuff,
Firecell, Lifeline or equivalent).
In order to protect against possible data corruption it is important to ensure the following points are
adhered to:
1. The cable screen must be connected to the SCRN terminal for each circuit
at the RSI.
2. The cable screen must not be connected to earth/ground at any point other than the
Control Panel (at the SCRN terminal provided). Do not connect the screen to a metal back
box.
3. The cable screen continuity must be maintained at every point of the circuit, using the
terminals provided or a suitable connection block.
4. Do not use a 4-core cable for 24V supply and communications, due to the possibility of data
corruption. It is essential that two 2-core screened cables are used, one for the 24V DC
supply and the other for communications.
Maximum Cable Lengths
The maximum total
cable length from the Control Panel to an RSI is 500 metres for power and
communication
.
Up to 8 RSIs can be used but they must all be within the maximum 500 metres cable length.
The maximum cable length from the RSI to the HOLD and RELEASE switches is 100 metres.
Refer to the
“Power Supply & Connections” and “Peripheral Bus Connections” sections below for further
details.
