6. LIFE

How long should a photocontrol last? This may be the most common question I'm asked. Also one of the most difficult to answer. The simple answer is:

A properly specified and manufactured control should last 10 years or more.

With current technology and a properly written specification, you can expect photocontrols to have a life of 8-12 years with less than a 1% per year failure rate. If, however, initial cost comes before good specifications, control life is often much shorter. Performance and longevity can be greatly enhanced by Engineering writing a comprehensive specification.

How long do controls last? Most of the ways that photocontrol manufacturers use to reduce the cost of a photocontrol also reduce life. As Purchasing tries for the lowest price, Engineering and Operations should make sure that quality does not suffer. Operations must let Engineering know about abnormal failure rates. Any photocontrol type that has more than 1% out of box or first year failures should be taken off standards until the shortcoming are fixed.

Performance and longevity can be greatly enhanced by your company's Engineering Department writing a comprehensive specification.

Incoming inspection must do regular testing to confirm that what is received meets the specification. It is DTL's experience that utilities that do incoming inspection get the best photocontrols from their suppliers. Alternatively, instead of incoming inspection, many utilities do supplier certification and follow-up audits. This usually involves a Engineer from the utility traveling to the manufacturing site. In the long run, it is a cost effective way to assure quality and to stay on top of your suppliers.

Remember: Maintenance is the biggest cost of your lighting system, your service crews must visit the lighting site as infrequently as possible. Make this happen by specifying the right product for your location and accepting the fact that higher initial cost may be required for quality, long life products.