Download CA‐NLH‐070  NLH 2015 Capital Budget Application  Page 1 of 2 Projects over $50,000 but Less Than $200,000 

CA‐NLH‐070 NLH 2015 Capital Budget Application Page 1 of 2 1 Q. Projects over $50,000 but Less Than $200,000 2 Tab 25 Construct Second Distribution Feeder, Nain: 3 Hydro outlines that during extreme operating conditions, customer service 4 entrance nominal voltage must range between 106 volts for single phase customers 5 and 110 volts for three‐phase customers to a maximum of 127 volts for a nominal 6 120‐volt service. Please outline what does Hydro mean when it refers to "extreme 7 operating conditions". 8 9 10 A. Table 1 displays the normal and extreme operating condition nominal voltage 11 ranges for many types of electrical services. This table was taken from CSA 12 Standard CAN3–C235–83 (R2006) – Preferred Voltage Levels for AC Systems 0 – 13 50,000 V, Table 3 ‐ Recommended Voltage Variation Limits for Circuits up to 1000 V, 14 at Service Entrances. 15 16 Standard CAN3‐C235‐83 (R2006) defines an extreme operating condition as follows: 17 Where voltages lie outside the indicated limits for normal 18 operating conditions but within the indicated limits for 19 extreme operating conditions improvement or corrective 20 action should be taken on a planned and programmed basis 21 but not necessarily on an emergency basis. Where voltages lie 22 outside the indicated limits for extreme operating conditions, 23 improvement or corrective action should be taken on an 24 emergency basis. The urgency for such action will depend on 25 many factors such as location and nature of load or circuit 26 involved, extent to which limits are exceeded with respect to 27 voltage levels and duration, etc. CA‐NLH‐070 NLH 2015 Capital Budget Application Page 2 of 2 Table 1: Recommended Voltage Variation Limits for Circuits up to 1000V, at Service Entrances Nominal System Voltages Single‐Phase (V) 120/240 240 480 600 Three‐Phase 4‐Conductor (V) 120/208Y 240/416Y 277/480Y 347/600Y Three‐Phase 3‐Conductor (V) 240 480 600 Voltage Variation Limits Applicable at Service Entrances Extreme Operating Conditions Normal Operating Conditions Lower Limit Upper Limit 106/212 110/220 125/250 127/254 212 220 250 254 424 440 500 508 530 550 625 635 110/190 220/380 245/424 306/530 112/194 224/338 254/440 318/550 125/216 250/432 288/500 360/625 127/220 254/440 293/508 367/635 212 424 530 220 440 550 250 500 625 254 508 635