20/10/2026
The Scope of Work says “replace like for like”... and the 1960s-built substation has no drawings.
Like for like with what, exactly?
For engineers working on legacy electrical infrastructure, this is a familiar starting point: missing schematics, unidentified cables, undocumented modifications and equipment that has outlived its records.
Consider a complete replacement of the LVAC distribution and protection panels in a 1960s substation.
Before detailed design starts, you need to establish what is actually installed, what it supplies and how the protection operates.
A detailed site survey helps establish:
LVAC supply sources, distribution arrangements, connected loads, cable sizes and earthing.
Existing protection functions, relay settings and CT/VT ratios, wiring and polarity.
Trip circuits, interlocks, alarms and interfaces with other equipment.
Panel dimensions, cable routes, access constraints and practical changeover requirements.
Missing information needs to be recorded and resolved through appropriate inspection, testing and operational coordination. A visual survey alone will not answer every question.
That evidence determines whether a replacement can preserve the existing functions or whether an upgrade requires revised protection, additional capacity, new interfaces or changes elsewhere in the network.
It also supports the network model and studies needed to verify fault levels, equipment ratings and protection coordination.
Without that baseline, assumptions can become design decisions, emerging during installation or commissioning as rework, delays and additional outages.
The site survey is part of the engineering, not simply preparation for it.
EPS combines available records with site audits, surveys and power system studies to give legacy upgrades, BESS developments and site expansions a verified basis for detailed design.
Talk to EPS about establishing your site data before design progresses.
✉️ [email protected]
📞 01642 987 240
