PASS & SEYMOUR / SENSORS & DIMMERS OCCUPANCY/VACANCY SENSORS & TIMERS Useful Calculations Examples of savings and payback EXAMPLE 1 Large office using a CX100 Passive Infrared Sensor Six 88-watt, 3-lamp fixtures = 0.528 kW x $0.086/kWh* = $0.04541/hr Savings = 35 hours per week Total hours saved = 1,820 hrs/yr Annual Savings = $82.65; 5 Year Savings = $413.23 Total estimated cost including power pack: (Product and Labor) = $140.00 Payback = 20.33 months ROI = $82.65 ÷ $140.00 = 59.03% EXAMPLE 2 Individual office using a CI2051 PIR Ceiling Sensor Three 88-watt, 3-lamp fixtures = 0.264 kW x $0.086/kWh* = $0.02270/hr Savings = 50 hours per week Total hours saved = 2,600 hrs/yr Annual Savings = $59.02; 5 Year Savings = $295.10 Total estimated cost: (Product and Labor) = $54.00 Payback = 10.98 months ROI = $59.02 ÷ $54.00 = 109.30% Restroom using a WT1105 Ultrasonic Occupancy Sensor Four 88-watt, 3-lamp fixtures = 0.352 kW x $0.086/kWh* = $0.03027/hr Savings = 75 hours per week Total hours saved = 3,900 hrs/yr Annual Savings = $118.05; 5 Year Savings = $590.27 Total estimated cost: (Product and Labor) = $160.00 Payback = 16.26 months ROI = $118.05 ÷ $160.00 = 73.78% *Based on 2004 US Government National average cost. Multi-Sensor Installation For applications requiring more than one sensor, the load per power pack should not exceed 225mA. Use the following table to calculate the maximum number of sensors per power pack. CX1051 8mA Examples: 2 x UT3052 (30mA) = 60mA 4 This is an acceptable load because it is less than 150mA. 4 x UT3052 (30mA) + 1 x S120/277/347EP(36mA) = 156mA 7 This is not an acceptable load because it is greater than 150mA. CI3051/CI305 CX100 UT3051/UT3052 9mA 8mA 30mA UT3053 35mA S120/277/347EP DT305 36mA 35mA 400 WWW.LEGRAND.US/PASSANDSEYMOUR SENSORS & DIMMERShttp://WWW.LEGRAND.US/PASSANDSEYMOUR