Specifications

Siemens Mobility, Traffic Solutions

Sopers Lane, Poole, Dorset

BH17 7ER

Version 10 Page 110 of 120 Status Issued

Last Editor harry.smyth Date 03 November 2014

Document

Name

GENERAL HANDBOOK FOR HEIMDALL

DETECTORS

Doc. No.

667/HB/31900/000

11 PERMITTED CABLE LENGTH ‘LOOK-UP TABLES’

This section assumes that the standard Siemens 24v AC Detector Supply transformer is

used.

The standard Siemens part numbers of the controller mounted AC Detector Supply kits

are assumed to be as follows.

Nominal 50VA, (2 amps) 667/1/27853/000

Nominal 160VA, (6.6amps) 667/1/20292/008

The following tables are provided to enable a very quick assessment to be made of the

suitability of a particular AC supply transformer and the required loading/cable runs.

These tables err on the ‘safe side’ and if particular installations do not fit the scenarios

presented then you will have to carry out the detailed calculations described in Section

11.

How to use the tables:

Determine how many other detectors are connected to the particular transformer.

Select the most appropriate table based on ‘point 1’ above. If there is no exact match

with the tables given choose the next highest.

Determine how many detectors are to be connected to the cable in question.

Determine the required cable length.

The table can then be viewed to see if standard ‘Serial’ (S) or ‘Parallel’ (P) supply feeds

should be used. A ‘Blank’ box is shown for situations which cannot be supported and a

re-design is necessary or a more detailed calculation is required, as described in Section

11.

11.1 Cable Type

Throughout these sections it is assumed that the installation has been completed with a

supply and return cable of 1 mm