A substation control house is a small building with a demanding job: it protects the protection, control, communications and DC equipment that runs the substation. Its design and construction are split among the utility or owner, the engineers, the equipment suppliers, the substation contractor and the general contractor.
Use the checklist below to define scope and interfaces before pricing. Requirements vary by utility, owner, equipment and project; confirm them with the responsible engineers and the applicable utility standards.
01Site-built or factory-built
Control houses may be site-built or factory-built. Factory-built buildings may arrive as shells, partly equipped or fully integrated. The choice changes what the general contractor builds and what the supplier furnishes, so settle it before pricing.
- Which building systems, panels and battery/DC equipment are factory-installed and which are installed on site
- Who furnishes the building, the panels, the battery system and the building systems in each case
- Foundations, transport, offloading, setting, anchorage and field connections, each assigned separately
02Utility standards and design responsibility
Many utilities have their own standards for control houses. Confirm which standards apply and who is responsible for each part of the design.
- Applicable utility standards, drawings and specifications
- Engineer of record for the building, foundations and building systems
- Protection, control and communications design responsibility
- Permit and inspection requirements for the site, and who obtains them
- Who reviews and approves submittals for building and equipment interfaces
03Foundations and site
Confirm foundation-design responsibility and coordinate geotechnical information, building and equipment loads, supplier anchor requirements, openings and setting tolerances. Issue coordinated, approved foundation and embed details before concrete placement.
- Foundation type and design, coordinated with the building or enclosure supplier
- Anchor bolts, embeds and openings from approved supplier drawings
- Finished floor elevation and site drainage around the building
- Delivery and crane access for factory-built enclosures and large equipment
- Setting tolerances and survey verification before delivery
04Cable entries and grounding
Cable routes into the control house and grounding connections tie the building to the rest of the substation. They are designed by others and built by several parties.
- Cable trench, conduit stub-ups and floor or wall entries, with locations from the approved design
- Sealing and fire-stopping of entries as specified
- Building grounding connections to the substation grounding system, as designed by the responsible engineer
- Installation, inspection and testing of the engineered bonding and ground-grid connections, including required verification before concrete placement or backfill
- Sequence between below-grade work, foundations and the substation contractor’s work
05Building systems
Building systems must address equipment heat loads and environmental limits, operating schedules and required redundancy, together with occupant ventilation and comfort requirements where applicable.
- HVAC sized for the equipment heat loads and environmental requirements in the design, including any redundancy
- Lighting, receptacles and station service power as designed
- Fire detection and any other life-safety systems required by the design
- Who furnishes and installs each building system in a factory-built enclosure
06Battery and DC systems
Battery systems carry their own design requirements. Make sure the building provisions match the selected battery system.
- Who furnishes and installs the battery, charger and DC distribution
- Battery area ventilation, spill containment and safety provisions as required by the design
- Floor loading and racking anchorage for the battery system
- Eyewash or other safety equipment where required by the design
- Battery technology and owner DC-system requirements confirmed, with storage, preservation, initial charging, commissioning, testing and acceptance responsibilities assigned in accordance with supplier instructions and the approved design
07Panel installation and connections
Setting panels and making connections often involves the utility, an EPC contractor or an equipment supplier as well as the GC. Assign each step.
- Who receives, stores, sets and anchors protection and control panels
- Who pulls, terminates and tests control and communications cabling
- Communications and SCADA connections and who makes them
- Protection of installed panels from dust and damage during remaining work
08Security and access
Utility sites often have their own access and security requirements.
- Door hardware, access control and alarm requirements from the utility’s standards
- Before work in an existing or energized substation: host and contractor hazard-information exchange, work boundaries, required personnel qualifications, approach restrictions, outage and clearance arrangements, and work authorization. Address crane operations, excavation and protection of existing cables and ground-grid conductors. Site access or an escort does not authorize energized electrical work
- Coordination with fencing, gates and site security by others
09Schedule and handover
The control house usually sits on the energization path. Tie its milestones to the substation schedule.
- Foundation readiness dates tied to enclosure or panel delivery
- Building systems operating before equipment requiring environmental control is installed
- Factory and site testing, battery/DC commissioning, protection-and-control functional testing, SCADA verification and acceptance responsibilities, distinguishing completion of the building package from authorization to energize or place substation systems in service
- Record drawings, warranties and operations documents at turnover
For a general control-room checklist, see the control room construction checklist and the control room scope matrix.