Specifications
Siemens Mobility, Traffic Solutions
Sopers Lane, Poole, Dorset
BH17 7ER
Version 10 Page 43 of 120 Status Issued
Last Editor harry.smyth Date 10 January 2014
Document
Name
GENERAL HANDBOOK FOR HEIMDALL
DETECTORS
Doc. No.
667/HB/31900/000
Copyright Siemens plc 2014 All Rights Reserved
5.2.3 Operating Current
The overall operating current will depend whether any additional facilities are provided.
Table 5-6 below lists the typical current requirements:
24V AC Supply 143mA
24V DC Supply 113mA
Table 5-6 – Single Lane VA 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 < 2ms 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 5-7 below
should be added to those shown in Table 5-6.
Additional Facility
24 VAC
24 VDC
Siemens SiTOS Serial Interface
(connected)
6 mA 5 mA
Siemens Wireless Interface (connected) 11 mA 10 mA
Table 5-7 – Additional Facilities Operating Current
Refer to Section 10 for details on power and cable length calculations.
5.2.4 Detector Installation Instructions
5.2.4.1 Detector Position
The detector should be located on the nearside primary signal pole (detector #1 – Figure
15 below) for the ‘nearside lane’ and offside primary signal (detector #2 - Figure 15
below) for the ‘outside lane’. The following factors may influence position:
Line of sight obstruction such as signs, trees etc.
More than two lanes on approach - one required on nearside pole and one on
offside.
Road layout permits better aim from offside pole.
Cabling requirements.
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.
5.2.4.2 Detector Height
The detector may be mounted at any height between 3.3 and 4m.
5.2.4.3 Detector Angle
The initial installation angle will change depending on the installation height and road
surface angle. As a guide the angle may be pre-set to:
25 degrees from horizontal