Specifications

Siemens Mobility, Traffic Solutions

Sopers Lane, Poole, Dorset

BH17 7ER

Version 10 Page 38 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

5.1.3 Operating Current

The overall operating current will depend whether any additional facilities are provided.

Table 5-2 below lists the typical current requirements:

24 VAC Supply 143 mA

24 VDC Supply 113 mA

Table 5-2 – Standard 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 A (max) for < 2 ms when the supply is 29 VDC.

AC Supply: 4.2 A (max) for < 2 ms when the supply is 29 VAC.

If the detector has additional facilities fitted then the currents listed in Table 5-3 below

should be added to those shown in Table 5-2.

Additional Facility

VAC

VDC

Siemens SiTOS Serial Interface

(connected)

6 mA 5 mA

Siemens Wireless Interface (connected) 11 mA 10 mA

Table 5-3 – Additional Facilities Operating Current

Refer to Section 10 for details on power and cable length calculations.