Following the fire that resulted in the loss of London Luton Airport’s previous Terminal Car Park 2, the replacement multi-storey car park was designed with enhanced fire-protection measures.

These included updated automatic fire-suppression systems, wet risers and an emergency lift. To ensure these critical systems would remain available during a mains power failure, the new car park required a completely independent secondary power supply.

P&I Group was appointed to assess the supplied load information, select an appropriately sized generator and provide a complete standby generator package. Our scope also included factory testing, specialist delivery, crane offloading and positioning, site acceptance testing support, and ongoing servicing and maintenance.

The generator was required to support some of the most important systems within the new car park, including two wet-riser pumps, two sprinkler pumps and the emergency lift.

These loads presented a significant generator-sizing challenge. Large electric motors demand considerably more power while starting than during normal operation. If several pumps were called upon simultaneously, the generator needed to absorb the combined starting current without an unacceptable drop in voltage or frequency.

The site’s five transformers were also supplied from a common electrical source. Although power was distributed through several transformers, this did not provide a genuinely independent supply for the fire-safety systems. A separate standby generator was therefore required to remove this single point of failure.

The generator needed to start automatically and be ready to accept the required load within 15 seconds. It also had to provide extended operation using HVO fuel, accommodate substantial fire-resistant power cables and meet the acoustic requirements of an operational airport environment.

Delivery presented another challenge. The size and weight of the generator, together with the secure and restricted nature of the airport site, required detailed logistics planning and a controlled crane lift into the designated compound.

After reviewing the project load schedule and the starting characteristics of the pumps and lift, P&I selected a p1050 Silent-S generator.

The acoustic-enclosed generator provides 1,035kVA prime power and 1,125kVA standby power. It incorporates a Perkins 4008TAG2A engine, Stamford alternator and an automatic generator controller configured to deliver the required start-up performance.

The supplied package included:

• A sound-attenuated, weather-resistant enclosure
• Automatic starting and remote signalling facilities
• A 2,500-litre fuel tank suitable for HVO
• Engine heater and battery charger
• Earth-fault protection
• A purpose-designed 1,600A power connection arrangement
• Interfaces for the project’s control and monitoring systems

Before delivery, P&I completed a comprehensive Factory Acceptance Test at its facility. The generator was tested progressively through its operating range, including full-load and impact-load testing. A cold automatic start of 8.2 seconds was recorded, comfortably within the project’s 15-second requirement.

P&I then coordinated the specialist transport and contract lift. A 100-tonne mobile crane and spreader-beam arrangement were used to lift the generator into its secure compound, where it could be connected to the wider emergency power system by the project installation team.

Following completion of the electrical installation by the wider project team, the generator underwent Site Acceptance Testing at London Luton Airport.

The generator successfully operated at its full tested load of 840kW while maintaining stable voltage and frequency. Load-step testing recorded response times of one second at 25% load and 3.7 seconds when progressing through 50% to full load.

The completed standby power system now provides an independent source of electricity for the replacement car park’s automatic fire-suppression systems, wet risers and emergency lift. If the normal electrical supply is lost, the generator starts automatically and supports the systems needed to protect people, property and airport operations.

P&I continues to support the generator through planned servicing and maintenance, helping ensure it remains ready to operate whenever required.