Keith Lane, P.E., RCDD/NTS Specialist, LC, LEED AP, Vice President, Engineering — SASCO — Seattle

UPS: Standby Power for Egress Lighting

In the first part of this series , I introduced the basics of UPS technology. This second installment gets more specific, covering lighting inverters used in commercial buildings for egress lighting. The National Electrical Code , Article 700, indicates that all egress lighting shall be backed up within 10 seconds after a power outage. NFPA 101, Life Safety Code , further mandates a minimum of 1 foot candle (fc), or 10 lux, and that no point shall be less than 0.1 fc (1 lux) measured along the egress path at floor level.