Hill Graham Controls SCR System PCBs
With over 30 years experience in designing, modifying, troubleshooting and repairing Ross Hill and Hill Graham type SCR Systems for drilling rigs, CONTRELEC are uniquely positioned to be able to offer advice, source and supply replacement PCBs.

Hill Graham Controls used many of the same printed circuit boards that Ross Hill used in the USA. However there were some which were modified, and others which were unique to Hill Graham systems. We are able to identify and supply replacements for both. Examples:
- Power Limit Mk II PCB (HGC Part P383T)
- Battery Charger PCB (HGC Part P378T)
- Logic Indicator Mk II PCB (HGC Part P382T)
- MV Triple Firing Board (HGC Part P561T)
AC and DC Modules
Hill Graham Controls in the UK frequently took a standard Ross Hill Controls module and added extra or enhanced functionality by installing additional circuit boards. Some of these upgrades were adopted by Ross Hill as standard: for example, the Speed Feedback Switch for improved engine stability in the AC Module.
CONTRELEC are able to provide spares and replacements by the same process thereby ensuring 100% compatibility and interchangeability of your new module with the existing set.
In particular we can source functional replacements for parts which have become obsolete, too expensive, or superceded by superior models.