Specifications

T400 Controller Facilities Manual
667/EB/20200/000 Page B-1 Issue 9
APPENDIX B) 50-0-50 Volt Controller
B.1 50-0-50 volt Controller
Note: This version of the T400 does not meet DTp specification MCE0141 in respect
of dimming voltages and voltage sensing. This is inherent in the 50-0-50 volt
output but it meets the equivalent figures which are multiplied by (50+50)/240.
The 50-0-50 volt controller is a version of the standard so that the voltages on the
cables leaving the controller are 50 volts A.C. nominal with respect to earth, rather
than the standard 240 volts, and are transformer isolated from the incoming mains
supply.
The voltage on feeds to signals and to auxiliary devices such as regulatory signs,
microwave detectors solar cells etc. is nominally 50-0-50 volt rms (50 Hz) with the
centre tap taken to earth. This requires all street furniture to be modified to enable
operation at these voltages. Low voltage dc supplies for detectors (nominal 24 volts)
are unaffected.
An additional circuit breaker can be provided to enable the 50-0-50 volt feeds to be
isolated with a single switch without switching the controller logic off. (This does not
include the 24 volts intended for supplying external loop detectors.)
For controller operation at 50-0-50 volt all street furniture must be modified using the
appropriate kits and additional hardware is required in the controller.