Eaton put through its paces by ambulance service

The ability to supply a vital switchboard in record time helped Eaton Electric secure the order for a new PLC-controlled main switchboard for the Cheshire and Merseyside area of North West Ambulance Service NHS Trust as part of a major refurbishment of its electrical power supply. In a second order, Eaton supplied an emergency generator and new uninterruptible power supplies form its Powerware business. The switchboard specification required delivery within 10 weeks of the official order. Electrical contractor Hayes Electrical & Building Services of Liverpool had to install the new switchboard as a freestanding unit in such a way that the existing switchgear (a loose-mounted busbar and MEM Excel and Glasgow fuse-switches) could be removed in stages as the new switchboard become operational. A new 236 kVA feeder will be provide by Core Utilities to replace the previous 110 kVA supply. The new switchboard comprises sections for essential and non-essential services. In the event of a power failure, a bus coupler opens automatically to isolate non-essential lads. Most essential services have uninterruptible power supplies to ensure continuous power while the emergency generator starts. The 150 kVA diesel starts automatically, and loads are progressively connected to avoid stalling. Eaton supplied a 1000 A fully tested Form 4 Type 6 switchboard with a 50 kA one-second fault rating. Incoming and outgoing cables have top entry. The generator supply is provided through a 250 A automatic changeover switch. A phase-failure relay ensures that the generator will start if there is a loss of supply in any phase, compared with all phases for the previous generator. Full metering, with direct-reading instruments, is provided on all essential and non-essential circuits. Transient-voltage surge suppression is also provided on essential and non-essential panels.

Related links:

• www.eatonelectrical.com/uk