Ten seconds can seem like a lifetime when you're in the dark. For Subhash Nangia, the 10 seconds allowed by the National Electrical Code for egress lighting was too long to reactivate high-intensity discharge (HID) lights after an outage.
"We decided to get a continuous backup power system because the HID lights took so long to come on again when we lost power," said Nangia, senior electrical engineer at the University of California-San Diego.
The mix of older equipment (from a variety of suppliers) required frequent repairs, was difficult to service, and created noise. To solve the problem, the university chose an integrated life safety system, designed to support the facility's total critical load package during power irregularities and emergency situations. This system serves as an advanced source of highly reliable continuous AC output.
"We were looking for a system compatible with HID lights that came with self diagnostics and a status display," explained Nangia. "The unit has a good reputation for performance, too."
It also runs more quietly than typical inverter systems. Without all that noise and with self-diagnostic operating and alarm circuits, this system stands out for those who want to be aware of equipment problems before an emergency situation arises.
Installed in three buildings, each unit consists of a microprocessor-controlled battery-operated centralized inverter power system with a wide variety of features and benefits including fully automatic self-monitoring and self-testing capabilities. The microprocessor automatically runs self diagnostic routines on more than 150 operating parameters and provides 21 audiovisual alarms, which alert the user to potential problems before an emergency occurs. Line conditioning provides a continuous source of clean power to connected equipment.
The inverter system also produces continuous "no break" AC output to connected lighting (including those products using electronic ballasts and HID lamp loads), egress systems, fire protection, communication, security, building management, and support functions. Models up to 15kVA capacity are offered. An optional facsimile modem system can monitor the inverter systems at multiple locations and automatically send status reports on the facility's life safety power readiness.