Specifications

T400 Controller Facilities Manual
667/EB/20200/000 Page A-1 Issue 9
APPENDIX A) SUPPLYING DC POWER FOR VEHICLE DETECTORS
Table APPENDIX A) -1 gives the total number of 24 volt above-ground detectors or
detector cards (2-channel and 4-channel) which can be driven from the internal 24v
power supply. This is qualified by the number of Expansion I/O cards and SDE/SA
cards which are also being supplied from the same Power Supply.
Table APPENDIX A) -2 to Table APPENDIX A) -5 show the distances at which
different numbers of detectors can be supplied by the 24V supply. The actual distance
is determined by the voltage drop along the detector supply cable.
Table APPENDIX A) -6 to Table APPENDIX A) -8 show the maximum number of
detectors that can be supported by both the small and large 27.5V Detector PSU.
Table APPENDIX A) -9 to Table APPENDIX A) -12 show the distances at which
different numbers of detectors can be supplied by the 27.5V supply. The actual
distance is determined by the voltage drop along the detector supply cable.
Table APPENDIX A) -13 and Table APPENDIX A) -14 cover SDE for
Siemens/Microsense and Sarasota systems.
Note that detectors should never be powered from a regulator when used with the
T400.
Power for ‘D’ Detectors can be obtained by fitting a 45v/0.5 Ampere unregulated
supply in the T400. See also Section 18.12. Maximum distances are given in Table
APPENDIX A) -15.