Electrical engineering,feasibility to energisation

We take on the electrical scope of a plant as a whole: load lists and demand assessment, incoming supply and transformer sizing, distribution architecture, protection philosophy and earthing. Where a scheme already exists we review it against the load as it stands today rather than as it was designed, and say plainly where it no longer holds.

• Load assessment, demand factors and transformer sizing
• HT and LT distribution architecture, and the single line that follows from it
• Protection philosophy and co-ordination, modelled in ETAP
• Earthing and lightning protection design, backed by soil resistivity measurement
• Specifications and technical evaluation for tendering
• Site supervision, and witness of testing where you want a second pair of eyes

Generator, governor, excitation and switchyard treated as one system, because on a small hydro set they behave as one. We have commissioned plants at sites in Ladakh and Arunachal Pradesh, where a return visit is measured in days, so the commissioning plan and the spares list matter as much as the drawings.

• Generator protection, excitation and automatic voltage regulation
• Turbine governor interfacing and unit control
• Switchyard layout, protection and metering
• Station auxiliaries: LT distribution, DC systems, battery and charger sizing
• Synchronising and grid interface
• Commissioning at remote sites, planned around the access you actually have

Layouts, schematics, calculations and protection schemes, issued as a package a contractor can build from, an inspector can approve and your own maintenance team can still read in ten years. The calculations are shown, not just their results, so the basis of a decision can be checked rather than taken on trust.

• Substations up to 765 kV, air and gas insulated
• Hydro power, coal washery, material handling and process plant electrical design
• ETAP power system modelling and full protection co-ordination
• Numerical relay settings, issued as a schedule ready to apply
• Drawings revised and reissued as site conditions change

A switchyard is where a plant meets the grid, and it is judged on two days: the day it is charged and the day it has to clear a fault. We take it from bay layout and clearances through busbar scheme, protection and earth mat, then stay on site for erection, pre-commissioning and charging. Air-insulated or gas-insulated, a new yard or an extension into one that cannot be shut down, the engineering is the same in kind — what changes is how the outage is planned.

• Bay layout, phase and section clearances, and structure loading
• Busbar scheme — single, main and transfer, or double bus — chosen against the duty, not by habit
• Protection, metering and control schemes, with relay settings issued as a schedule
• Earth mat designed from measured soil resistivity, with step and touch potential checked
• Erection and pre-commissioning of isolators, breakers, CTs, PTs, CVTs and lightning arrestors
• Charging, load trials and documented handover — including extensions worked into a live yard

Our own engineers on site, through to energisation and handover. Where you already have an erection contractor we supervise instead, which usually costs less and keeps your existing arrangements intact. Testing is done with our own instruments and reported with the readings, not a pass mark.

• Erection and installation of HT and LT systems, or supervision of your contractor
• Pre-commissioning checks, loop checking and functional testing
• Routine and special testing of transformers, switchgear, breakers and relays
• Protection relay testing and calibration against the approved settings
• Energisation, load trials and documented handover
• Relays integrated into your existing SCADA, or a new one

Panels outlive the plant they were designed for. Rather than replace a sound enclosure, we replace what has aged inside it — electromechanical relays for numerical, obsolete breakers for current equivalents, wiring and terminations where they no longer meet the duty — and reissue the schematics so the drawings match the panel again.

• Electromechanical relays replaced with numerical, with fresh settings
• Obsolete breakers and contactors replaced with current equivalents
• Re-wiring, re-termination and labelling to match the revised scheme
• Modified schematics and a fresh co-ordination study for today's load
• Communication added so an old panel reports into SCADA
• Carried out in shutdown windows, planned around your outage

An audit that is worth acting on rests on measurement rather than nameplate data. We log the load, measure power factor and harmonics where they matter, thermograph the joints that are actually running warm, and report what a change would save against what it would cost. Condition testing on transformers and switchgear is reported the same way.

• Load logging, power factor and harmonic measurement
• Thermography of joints, terminations and switchgear under load
• Transformer condition testing: tan-delta, SFRA, partial discharge, oil filtration
• Soil resistivity testing and earth resistance measurement
• Feasibility reports with costed recommendations
• Supply of electrical spares