Telephone+44 (0)1494 526270


CONTRELEC is a team of experienced electrical engineers with over 20 years experience in electrical design, manufacturing and commissioning with particular expertise with Ross Hill and Hill Graham SCR systems. We are able to supply spare parts, repair, test and calibrate AC and DC control modules and PCBs used on Ross Hill and Hill Graham SCR Systems.

We design, deliver and support electrical engineering projects, from simple machine controls to large scale production and process line systems. Our key skills include:

AC Modules

AC and DC Control Modules Modification, Calibration and Repair

We calibrate and repair Hill Graham and Ross Hill type AC and DC Control Modules. We provide spare parts and incorporate many of the internal modifications which are a feature of many Hill Graham Controls systems. Our unique simulators feature variable frequency and voltage supplies for a more realistic testing environment.
Hill Graham and Ross Hill Spare Parts

Hill Graham and Ross Hill Spare Parts

Contrelec offer competitive pricing and fast delivery on all Ross Hill Controls and Hill Graham Controls spare parts. This includes difficult-to-source Printed Circuit Boards (PCBs) and other bespoke components, such as Foot Throttle and Hand Throttle assemblies. We are able to engineer solutions to replacing obsolete parts with modern substitutes and ensure the upgrade meets the technical requirements.
Drilling Rig and Ship Switchboard Design

Drilling Rig SCR Systems and Switchboard Design

Utilising modern Electrical and Mechanical 3D CAD software we accurately engineer switchboard designs. All aspects of the design are modelled including components, busbars, insulation barriers, wireways, trunking, labels and instruments. The benefits of 3D design include: improved build time, accurate design checking, easy to understand assembly drawings and total design confidence. Our scope ranges from simple starter control panels up to complete containerised power generation and distribution solutions.

Short Circuit Calculations, Protective Device Co-Ordination and Harmonic Analysis

Short Circuit Calculations, Protective Device Co-Ordination and Harmonic Analysis

Using sophisticated software we are able to model power systems and calculate short circuit levels to ANSI and IEC standards. From the same on-line drawing we can generate time/current co-ordination curves and a comprehensive schedule of device settings. Our Harmonic Analysis tool is able to accurately predict expected levels of total harmonic distortion introduced by variable speed drives, UPS's and other harmonic sources, and analyse the effect of adding filters to the system.