TC12 Installation, Commissioning & Maintenance Handbook
5.4 MAINTENANCE
A 1 A mains input fuse (part number 518/4/98042/001) is located within the front
panel fuseholder. A 2 A fuse (part number 518/4/98009/004) within the chassis
unit provides protection against certain types of traffic control equipment fault, e.g.
a supply rail wrongly connected to the common signal return wire.
The mains plug is fused with a 2 A fuse (part number 518/4/98020/001)
The PSU (part number 605/4/97029/014) is a Coutant Power Pack (Model HSB12-
1.7) rated at 12 V 1.7 A fully regulated. The unit supplies power to the two printed
circuit boards (i.e. logic circuitry and relays) and LEDs.
666/HE/43100/000 Page 164 Issue 9