Specifications
Siemens Mobility, Traffic Solutions
Sopers Lane, Poole, Dorset
BH17 7ER
Version 10 Page 55 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
Copyright Siemens plc 2014 All Rights Reserved
5.5.3 Operating Current
The overall operating current will depend whether any additional facilities are provided.
below lists the typical current requirements:
24V AC Supply 143mA
24V DC Supply 113mA
Table 5-18 – Detector Operating Current
Note: When power is first applied to the detector the following surge currents are drawn
from the supply:
DC Supply: 3.2 Amps (max) for < 2 ms when the supply is 29V DC.
AC Supply: 4.2 Amps (max) for < 2 ms when the supply is 29V AC.
If the detector has additional facilities fitted then the currents listed in Table 5-19 below
should be added to that shown in .
Additional Facility
24 VAC
24 VDC
Siemens SiTOS Serial Interface
(connected)
6 mA 5 mA
Siemens Wireless Interface (connected) 11 mA 10 mA
Table 5-19 – Additional Facilities Operating Current
Refer to Section 10 for details on power and cable length calculations.
5.5.4 Detector Installation Instructions
5.5.4.1 Detector Position
The detector should be located on a suitable mounting pole located alongside the
detection zone.
Please ensure the installation location of the detector is clear from obstructions, such as
signs, trees etc. such that there is a clear line of sight from the detector to the road.
Failure to adhere to this recommendation will reduce detector performance.
5.5.4.2 Detector Height
The detector should be located on a suitable mounting pole located alongside the
detection zone. The detector may be mounted at any height between 3.4 and 8m, with
the 4m height considered optimum. Ensure that the appropriate height range has been
selected, using the appropriate DIP switches, as detailed in section 5.5.5 or using the
appropriate terminal command DMH.
The equivalent loop length, along direction of travel, will vary depending on installation
height, thus:
4m – equivalent loop size 1.8m
6m – equivalent loop size 2.3m
8m – equivalent loop size 2.7m
The factory default is for installation heights ~4.0m.