IN Brief:
- MSSL has warned that heatwave conditions increase pressure on LV switchboards in critical buildings.
- The company points to BS EN IEC 61439-2 compliance and ASTA certification for temperature rise and short-circuit withstand.
- Data centres, hospitals, logistics sites, and plant rooms face higher resilience risk as operating temperatures rise.
Michael Smith Switchgear has linked rising UK heatwave conditions to low-voltage switchboard resilience, warning that higher plant room temperatures can increase risk across critical buildings.
The company has highlighted the role of LV switchboards in data centres, hospitals, logistics hubs, and other high-impact sites where dedicated LV rooms sit behind core operations. When temperatures in plant and switch rooms exceed the conditions many buildings were designed around, electrical distribution equipment can face additional thermal stress.
MSSL manufactures bespoke LV switchboards in line with BS EN IEC 61439-2. Its assemblies are independently certified by ASTA for temperature rise and short-circuit withstand, providing verification that internal components remain within safe operating limits under defined conditions. Non-compliant assemblies can be exposed to overheating, insulation damage, nuisance tripping, and more serious safety risks.
Although the first response to heatwave risk often focuses on cooling, electrical distribution equipment is part of the same resilience chain. A building may have efficient HVAC equipment and still carry risk if LV infrastructure is operating close to thermal limits. Switchboards, busbars, protective devices, and internal components must be designed and verified for the conditions in which they operate.
BS EN IEC 61439-2 sets requirements for low-voltage power switchgear and controlgear assemblies. The standard addresses verified assembly performance, including temperature rise, short-circuit withstand, dielectric properties, protection against electric shock, mechanical operation, and internal electrical circuits. Compliance provides the design and testing framework for equipment that must remain safe under load.
Data centres show the pressure clearly. Server cooling receives most attention because IT loads are temperature-sensitive and high-density, yet the electrical pathway feeding those loads is equally critical. LV switchboards distribute power to downstream systems, UPS equipment, cooling plant, and other essential loads. If the switchboard overheats or trips, the resilience of the wider facility is compromised.
Hospitals and logistics sites create different but equally demanding operating conditions. Hospitals require continuity for clinical services, medical equipment, lighting, ventilation, sterilisation, diagnostics, and emergency systems. Logistics hubs depend on automated handling, refrigeration, IT systems, charging infrastructure, lighting, and security. In each case, power distribution failure can affect operations far beyond the switchroom.
Load growth across the built environment is adding further pressure. The slowdown and regional variation seen in UK public charger rollout does not remove the longer-term electrical demand from EV infrastructure, heat pumps, data centres, automation, and building services. As connected loads rise, thermal performance and spare capacity become harder to treat as secondary design considerations.
Heatwaves narrow operating margins. Electrical equipment is rated against assumptions about ambient conditions, load, enclosure design, ventilation, and installation environment. If plant rooms run hotter than expected, the distance between normal operation and overheating can shrink, increasing the likelihood of derating, nuisance operation, accelerated ageing, or failure.
Verified assemblies are especially important where switchboards are bespoke. Custom equipment can be necessary in constrained plant rooms, retrofit projects, data centres, hospitals, and industrial buildings, but bespoke design must not mean uncertain performance. Testing and certification provide evidence that the assembly behaves as intended under relevant electrical and thermal conditions.
Electrical rooms are also becoming more crowded. Retrofitted EV charging, solar PV, storage, backup generation, UPS upgrades, and building expansion can all add equipment to spaces not originally planned for that density. That can affect ventilation, access, fault levels, discrimination, and maintenance.
MSSL’s warning lands at a practical point in the electrification cycle. More electricity is being pushed through building infrastructure, while climate conditions place additional stress on equipment rooms. LV switchboards are not the most visible part of the energy transition, but they are among the assets most likely to determine whether critical buildings remain safely powered when demand and temperature rise together.
