CareHomeDeskCareHomeDeskSolar PV installations on care home roofs introduce live DC cabling that presents different risks from standard AC electrical systems. DC cabling remains live even when the inverter is off, requiring specific fire service isolation procedures. BS 7671 and MCS standards require annual inspection and periodic PAT of the AC side.
Unlike the AC wiring in the rest of the building, the DC cabling between solar panels and the inverter remains live whenever there is daylight falling on the panels, regardless of whether the inverter or any isolator switch downstream has been turned off. This means standard assumptions about isolating a circuit by switching off at the consumer unit do not apply to the DC side of a PV system, and anyone working on or near the array, including Fire and Rescue Service personnel, needs this understood in advance.
Because DC cabling cannot be fully de-energised during daylight, Fire and Rescue Services have issued specific guidance on approaching buildings with PV systems during an incident. Good practice is for the installation to include a clearly labelled DC isolator accessible from ground level, and for a fire safety information sheet describing the system layout, isolation points and any battery storage to be located in the meter room or main electrical intake position where attending crews would expect to find it.
BS 7671 and the Microgeneration Certification Scheme (MCS) standards under which most domestic-scale PV systems are installed call for annual visual inspection of the array, mounting system and accessible cabling, alongside periodic electrical testing appropriate to the installation. The AC side of the system, including any inverter and associated switchgear, falls within the scope of routine PAT and EICR testing regimes alongside the rest of the building's electrical installation.
PV installations completed before around 2019 commonly predate more recent tightening of DC isolation and fire safety information requirements, and a system installed to the standards in force at the time may not meet what is now considered good practice. Operators inheriting an older PV installation, whether through acquisition of a building or long-standing ownership, should commission a review against current DC isolation and fire information requirements rather than assuming the original installation certificate remains sufficient evidence of compliance.
Confirm the DC isolator is present, correctly labelled and genuinely accessible from ground level without requiring roof access, confirm a current fire safety information sheet is displayed at the meter room or intake position, and ensure the AC side of the installation is included within the building's normal EICR and PAT testing schedule rather than treated as a separate system that falls outside routine electrical compliance checks.
CareHomeDesk gives you compliance checklists, maintenance logs, and contractor management tools built around exactly this kind of knowledge.