McLellan’s electrical engineering experience is comprehensive and encompasses power generation, transmission and distribution with specific emphasis on distribution systems associated with a range of industrial processes. Services cover design, specification, budget preparation, tender evaluation and project management, including provision of quality assurance, surveillance during plant manufacture and erection, cost control and contract co-ordination.

Our electrical engineering services include:

Transmission and distribution systems services - McLellan carries out design, project engineering and site supervision and maintenance of electrical transmission and distribution systems.

Grid connections - before committing funds to an embedded generation scheme, it is important to know whether the connection is viable and also demonstrate to the Grid or District Network Operator that their network will not be adversely affected by the connection. McLellan specialists can model the client’s distribution network and the connection and carry out the justification calculations necessary to satisfy both parties.

Industrial distribution - McLellan can assist clients with developing specifications for specialist industrial and heavy process electrical equipment including furnace transformers, power converters, motor control centres, drives and inverters, motors, emergency power systems, generators and uninterruptible power supplies.

Power system studies - industry is constantly changing with new plant and equipment being added to production facilities to manufacture increased product ranges or plant being re-configured to meet changing requirements. Similarly, the electrical infrastructure supporting a plant needs to be adapted to reflect these new circumstances. McLellan conducts power system studies that can be used to identify current or future problems in a network and to provide guidance in the planning of extensions or upgrades to the electrical network.

  • Static studies - static studies include load flow, fault level and harmonic analysis. Load flow analysis is used to determine the loading of cables and other distribution equipment, together with voltage profiles for normal and abnormal operating conditions. They allow the network performance under various outage conditions to be investigated. The effect of system losses and power factor correction, the need for system reinforcement and confirmation of economic transmission can then follow. McLellan conducts these studies for the design of new systems or extensions to existing systems.
  • Dynamic studies - the stability of a network is affected by the energy balance and the ability to generate sufficient restoring forces to counter system disturbances and maintain system voltage levels and common system frequency. McLellan typically carries out these studies for clients with their own generating plant, particularly for the purposes of emergency generation, where security of supply under all conceivable fault conditions is paramount.
  • Short circuit analysis - Short circuit analysis allows the make and break fault levels in the system for both symmetrical and asymmetrical, low or high impedance faults to be determined. This in turn allows for the correct determination of system component ratings, for example the fault level capability of circuit breakers. The analysis also allows investigation of protection requirements along with the identification of any changes necessary to the system to reduce fault levels. McLellan can conduct the necessary analysis to establish under which conditions a client’s switchgear is overstressed and recommend operating configurations to avoid them.
  • Arc flash studies - The purpose of an arc flash assessment is to determine the severity of the arc flash hazard in an electrical installation by accurately modelling the system using specialist software. McLellan can conduct arc flash assessments for a range of electrical installations. On completion of the analysis, recommendations are typically made to minimise the potential hazards. Arc flash studies for older switchgear are increasingly in demand.