LSEGG307A 9080F • Describe the acceptable methods for determining the maximum demand on an installation’s consumer’s mains. • Calculate the maximum demand for the consumer's mains for given installations up to 400 A per phase. What is Maximum Demand? MD Is the “Maximum continuous current that flows in a circuit for a period of 15 minutes or longer” AS/NZS 3000 1.6.3 Why not just put a cable size in, that will handle the current rating for the maximum current rating of the appliance? What is Maximum Demand? Domestic stove rated at 5kW Max current = 22A Min cable size = 6mm2 By calculation Max current = 16A Min cable size = 2.5mm2 AS/NZS 3000 Table C4 AS/NZS 3000 2.2.2. Calculation Assessment Measurement Limitation “If the measured current is larger than any of the listed methods, then the MD is considered the measured value” AS/NZS 3000 Clause 2.2.2 (d) “… may be the ….sum of the current settings of the circuit breakers protecting the associated final sub-circuits….” 10+10+16+16+32 = By Calculation 16mm2 84 Amps 36 Amps MD = ? 10mm2 2.5mm2 20 metres 10A L1 46 metres 10A L2 16A P1 16A P2 Domestic House 32A Stove Domestic Table C1 Non-domestic Table C2 Non- domestic Energy Demand Table C3 Single House Table C1 Column 2 Lighting Load groups Ai & Aii Batten holder = 1 light point 25 lighting points = 1 -20 = 3 A 21 -25 = 2 A 5A Single House Table C1 Column 2 Lighting Load groups Ai & Aii Chandelier or Multi-globe fitting = Number of points = Number of globes = 3 points Single House Table C1 Column 2 Lighting Load groups Ai & Aii Power points above 2.3 m for lighting = 1 point Note “e” Exhaust fans below 150W = 1 point Single House Table C1 Column 2 Lighting Load groups Ai & Aii Track lights = Every metre = Note “d” 2 x 2.6 metres track light = 2 points 5 points per track = 10 points Single House Table C1 Column 2 Lighting Load groups Ai & Aii IXL Tastics, Heat lamps etc Not regarded as “Lighting” Fixed Space Heating Load Group “D” Single House Table C1 Column 2 Lighting Load groups Ai & Aii Outside Lighting Floodlighting, Swimming Not lighting around Pool, Tennis courts, etc house walls If total bigger If less than than 1000W 1000W Load Group “Aii” Load Group “Ai” A house consists of the following: 36 light fittings, 3 consisting of 3 lamp combinations 3 bathroom exhaust fans 2 x 750W heat lamp, fan, light combinations 3 x 2metre track lights 12 wall lights around the veranda 6 x 100W bollard lights on driveway 6 x 400W metal halide flood lights for pool 6 x 100 = 600 6 x 400 = 2400 3000 W 230V Determine the lighting load in Amps Assume to be <150W Ai Ai D Ai Ai Aii Aii 33 + (3 x 3) = 42P 3P 3 x 2 x 2 = 12P 12P 13.04A A house consists of the following: 36 light fittings, 3 consisting of 3 lamp combinations 3 bathroom exhaust fans 2 x 750W heat lamp, fan, light combinations 3 x 2metre track lights 12 wall lights around the veranda 6 x 100W bollard lights on driveway 6 x 400W metal halide flood lights for pool 42P 3P 12P 12P 69P 1 – 20 = 21 – 40 = 41 – 60 = 61 – 69 = Ai Ai D Ai Ai Aii Aii 33 + (3 x 3) = 42P 3P 3 x 2 x 2 = 12P 12P 13.04A 3A 2A 2A 2A 9A + 13.04A = 22.04A Broken up evenly 36 light fittings 3 A B C 12 Fittings / 3A 3A 3A Should indicate how it is to be broken up across the three phases NOT 36 light fittings = 3A + 2A = 5A 3 A B C 1.6 1.6 1.6 A house consists of the following: Broken up evenly over 3 Phases 36 light fittings, 3 consisting of 3 lamp combinations 3 bathroom exhaust fans Divide by 3 2 x 750W heat lamp, fan, light combinations 3 x 2metre track lights 12 wall lights around the veranda 6 x 100W bollard lights on driveway 6 x 400W metal halide flood lights for pool 14P 1P 4P 4P 23P Ai Ai D Ai Ai Aii Aii 11 + (1 x 3) = 14P 1P 1 x 2 x 2 = 4P 4P 4.35A 1 – 20 = 3A 21 – 23 = 2A 5A + 4.35A = 9.35A / Power Points Double Power Points 36 Double Power Points 6 Single power points Notes h 36 x 2 =72P 6P 1 – 20 = 78P 21 – 40= 41 – 60 = 61 – 78 = 10A 5A 5A 5A 25A Power Points Notes h Double Power Points 36 Double Power Points 6 Single power points 36 x 2 =72P 6P AND Other Direct Wired Equipment that is <10A • Air conditioners • Cook tops • Water heaters 78P 1 – 20 = 21 – 40= 41 – 60 = 61 – 78 = 10A 5A 5A 5A 25A Power Points NOT 15 A Power Points Other Equipment that is Covered in Load Groups below C D E&F G Ranges, Laundry equipment Fixed Space Heating or cooling equipment Water Heaters Spa & Swimming Pool Heaters 15 A Power Points suppling this equipment is covered under each load group A house consists of the following: 20 Double power points 8 Single power points 8A swimming pool pump 34 x 15A power points 12A Air-conditioner supplied via a 15A power point 14A Pool heater direct wired Bi Bi Bi Bii D G Determine the Power point load in Amps 20 x 2 = 40P 8P 1P 10A - A house consists of the following: 20 Double power points 8 Single power points 8A swimming pool pump 3 x 15A power points 12A Air-conditioner supplied via a 15A power point 14A Pool heater direct wired 40P 8P 1P 49P Bi Bi Bi Bii D G 1 – 20 = 10A 21 – 40 = 5A 41 – 49 = 5A 20A + 10A = 30A 20 x 2 = 40P 8P 1P 10A - • • • • Cook tops Wall ovens Washing machines Clothes driers Must be over 10A If supplied via a power point That power point is NOT included in Bi, Bii or Biii An installation has: 2.3 kW Cook top 4 kW Wall oven 50% of connected Load 6.3 kW of Load Group C (6300/230) x 0.5 = 13.7A • • • • IXL Tastics Heat lamps Air conditioners Heaters Under floor heating Must be over 10A If supplied via a power point That power point is NOT included in Bi, Bii or Biii 75% of connected Load If reverse cycle Air-conditioner is used only the highest system is to be taken into account Unless it is multi zone, when both heating and cooling could operate simultaneously Water Heaters 15 litre heater with a 2.4kW element 2400/15 = 160 W/L Load Group E 33.3% of connected load • Instantaneous • Quick recovery If greater than 100W/L Load Group F 300 litre heater with a 2.4kW element 2400/300 = 8 W/L 100% of connected load • Storage • Off peak A house consists of the following: Ai Ai Bi Bi C D F 41 x 50 W down lights 2 x 60 W exhaust fans 4 x Single 10 A socket outlets 22 x Double 10 A socket outlets 1 x 10kW range 1 x Permanently connected air conditioner (full load current of 13 A) 1 x 4.6 kW continuous HWS A house consists of the following: Ai Ai Bi Bi C D F 41 x 50 W down lights 43P 3 + 2 + 2 = 2 x 60 W exhaust fans 4 x Single 10 A socket outlets 22 x Double 10 A socket outlets 1 x 10kW range 1 x Permanently connected air conditioner (full load current of 13 A) 1 x 4.6 kW continuous HWS 7A A house consists of the following: Ai Ai Bi Bi C D F 41 x 50 W down lights 2 x 60 W exhaust fans 4 x Single 10 A socket outlets 44 + 4 = 48P 10 + 5 + 5 = 22 x Double 10 A socket outlets 44P 1 x 10kW range 1 x Permanently connected air conditioner (full load current of 13 A) 1 x 4.6 kW continuous HWS 7A 20A A house consists of the following: Ai Ai Bi Bi C D F 41 x 50 W down lights 2 x 60 W exhaust fans 4 x Single 10 A socket outlets 22 x Double 10 A socket outlets 1 x 10kW range (10000/230) x 0.5 = 1 x Permanently connected air conditioner (full load current of 13 A) 1 x 4.6 kW continuous HWS 7A 20A 21.7A A house consists of the following: Ai Ai Bi Bi C D F 41 x 50 W down lights 2 x 60 W exhaust fans 4 x Single 10 A socket outlets 22 x Double 10 A socket outlets 1 x 10kW range 1 x Permanently connected air conditioner (full load current of 13 A) 1 x 4.6 kW continuous HWS 13 x 0.75 = 7A 20A 21.7A 9.75A A house consists of the following: Ai Ai Bi Bi C D F 41 x 50 W down lights 2 x 60 W exhaust fans 4 x Single 10 A socket outlets 22 x Double 10 A socket outlets 1 x 10kW range 1 x Permanently connected air conditioner (full load current of 13 A) 1 x 4.6 kW continuous HWS 4600/230 = 7A 20A 21.7A 9.75A 20A A house consists of the following: Ai Ai Bi Bi C D F 41 x 50 W down lights 2 x 60 W exhaust fans 4 x Single 10 A socket outlets 22 x Double 10 A socket outlets 1 x 10kW range 1 x Permanently connected air conditioner (full load current of 13 A) 1 x 4.6 kW continuous HWS 7A 20A 21.7A 9.75A 20A 78.45A Not all single phase loads will break up evenly over three phases But the phases must not be unbalanced by more than 25A NSW S&IR Clause 1.10.3 A house consists of the following: Ai A 30 x Light points + 2 x Exhaust fans Ai B 18 x Lights Aii C 6 x 400W mercury vapour flood lights Bi A 15 x Double power points (p/p) Bi B 10 x Single p/p & 15 x Double p/p Bii C 3 x 15A Single p/p C A 1 x 4.1kW wall oven C B 1 x 4.6kW cook top F C 1 x 3.6kW heat pump HWS A D B C 1 x 5.7kW 3 Air conditioner A house consists of the following: Ai A 30 x Light points + 2 x Exhaust fans 32P Ai B 18 x Lights 3+2A = 5A 3A 18P Aii C 6 x 400W mercury vapour flood lights ((6x400)230)x0.75 = Bi A 15 x Double power points (p/p) Bi B 10 x Single p/p & 15 x Double p/p 30P 10+30P 10+5A = 7.83A 15A 20A 10+5A = Bii C 3 x 15A Single p/p C A 1 x 4.1kW wall oven C B 1 x 4.6kW cook top F C 1 x 3.6kW heat pump HWS 10A (4100230)x0.5 = C 10A (4600230)x0.5 = 15.65A 3600230 = A D B 8.91A 6.17A 1 x 5.7kW 3 Air conditioner (5700x0.75)(√3 x400) = 6.17A 6.17A 35.1A 39.2A 40.2A Submains to individual units Unit 1 MSB Unit 2 Unit 3 Columns 3, 4 or 5 Column 2 How many units are there? How are they spread across the 3 phases? 6 Units 3 = 2 Units / Phase Use Colum 3 18 Units 3 66 Units 3 = 6 Units / Phase Use Colum 4 = 22 Units / Phase Use Colum 5 A house consists of the following: Ai 26 x Light points 26 + 4 = 30P 3A + 2A = 5A Ai 2 metres of light track 2 x 2 = 4P Aii 2 x 750W flood lights 1500W (1500W/230V)x0.75 10A + 5A + 5A = 20A Bi 26 x Double 10 A socket outlets 26 x 2 = 52P Bi 5 x Single 10 A socket outlets 4.9A 52 + 5 = 57P Bii 1 x 15A Single socket outlet 10A C 1 x 5.6kW wall oven / cook top (5600W/230V)x0.5 12.2A D 1 x 3.6kW air conditioner (3600W/230V)x0.75 11.7A F 1 x 2.4kW storage HWS (Heat pump) (2400W/230V) 10.4A 74.2A 9 Units consists of the following: 9 Units 3 = 3 Units / Phase Use Colum 3 Ai 26 x Light points 6A Ai 2 metres of light track Aii 2 x 750W flood lights Not counted Bi 26 x Double 10 A socket outlets 10A + (5A x 3) = 25A Bi 5 x Single 10 A socket outlets Bii 1 x 15A Single socket outlet 10A C 1 x 5.6kW wall oven / cook top 15A D 1 x 3.6kW air conditioner (3600W/230V) x 0.75 x 3 F 1 x 2.4kW storage HWS (Heat pump) 35.2A 6A x 3 = 18A 109A 30 Units consists of the following: 30 Units 3 = 10 Units / Phase Use Colum 4 Ai 26 x Light points 5A + (0.25A x 10) = 7.5A Ai 2 metres of light track Aii 2 x 750W flood lights Not counted Bi 26 x Double 10 A socket outlets 15A + (3.75A x 10) = 52.5A Bi 5 x Single 10 A socket outlets Bii 1 x 15A Single socket outlet C 1 x 5.6kW wall oven / cook top D 1 x 3.6kW air conditioner (3600W/230V) x 0.75 x 10 F 1 x 2.4kW storage HWS (Heat pump) 10A 2.8A x 10 = 28A 117A 6A x 10 = 60A 275A 66 Units consists of the following: 66 Units 3 = 22 Units / Phase Use Colum 5 Ai 26 x Light points 0.5A x 22 = 11A Ai 2 metres of light track Aii 2 x 750W flood lights Not counted Bi 26 x Double 10 A socket outlets 50A + (1.9A x 22) = 91.8A Bi 5 x Single 10 A socket outlets Bii 1 x 15A Single socket outlet C 1 x 5.6kW wall oven / cook top D 1 x 3.6kW air conditioner (3600W/230V) x 0.75 x 22 F 1 x 2.4kW storage HWS (Heat pump) 10A 2.8A x 22 = 61.6A 258A 100A + (0.8A x 22) =118A 550A 16 Units 3 A 5 Units Col 3 = 5.33 Units / Phase B 5 Units Col 3 C 6 Units Col 4 But the phases must not be unbalanced by more than 25A NSW S&IR Clause 1.10.3 16 Units consists of the following: 5 Units / A & B Ai 26 x Light points Bi 26 x Double 10 A socket outlets Bi 5 x Single 10 A socket outlets Use Colum 3 6A 10A + (5A x 5) = 35A Bii 1 x 15A Single socket outlet 10A C 1 x 5.6kW wall oven / cook top 15A D 1 x 3.6kW air conditioner (3600W/230V) x 0.75 x 5 F 1 x 2.4kW storage HWS (Heat pump) (2400230V) x 5 = 58.7A 52.2A 176.9A 16 Units consists of the following: 6 Units / C Use Colum 4 5A + (0.25A x 6) = Ai 26 x Light points Bi 26 x Double 10 A socket outlets Bi 5 x Single 10 A socket outlets 6.5A 15A + (3.75A x 6) = 37.5A Bii 1 x 15A Single socket outlet 10A C 1 x 5.6kW wall oven / cook top D 1 x 3.6kW air conditioner F 1 x 2.4kW storage HWS (Heat pump) 2.8A x 6 = (3600230) x 0.75 x 6 16.8A 70.4A 6A x 6 = 36A 177.2A 16 Units 3 A 5 Units Col 3 176.6A = 5.33 Units / Phase B 5 Units Col 3 176.6A C 6 Units Col 4 177.2A Loads that are used by all the unit dwellers • Driveway/ parking lighting • Stairwell lighting • Power points for cleaners • Lifts • Swimming pool pumps 16 Units have a communal load consists of the following: H 20 x 80 W bollard Lights ((20x80)230) + ((30x 60)230) = 14.78A H 30 x light points I 15 x Single 10 A socket outlets 2A x15= 30 but maximum of 15A 15A Ji 1 x 3.6kW HWS for cleaners room (3600230) x 0.5 = 7.8A Jii 1 x 3.6kW Air conditioner for lobby (3600230) x 0.75 = 15A D 1 x 12A pool pump/filter 12A E 1 x 15A lift motor Table C2 Colum 2 15 x 1.25 = 18.75A 83.33A These circuits could also be divided across three phases In a Factory On each Phase 20 x 10A single power points 1000W + 19 x 750W = 15.25kW 15250 ÷ 230 = 66.3 Amps In areas with air conditioning 20 x 10A single power points 1000W + 19 x 100W = 2.9kW 2900 ÷ 230 =12.6 Amps 5 x 10A 3 outlets Treat as B(i) 1000W + 4 x 750W = Per Phase 4kW 4000 ÷ 230 = 17.4 Amps 2 x 32A 3 outlets 5 x 20A 3 outlets 75% x 32A 32A + 24A + 75A = Per Phase 75% x 20A x 5 131Amps In Factories 2 x 30A 3 motors 3 x 15A 1 motors 75% x 30A 30A + 22.5A + 1 per phase 50% x 3 x 15A 22.5A = 75 Amps AS/NZS 3000 C2.5.2.2 (b) 3 x 20A 3 Welders Majority of welders only use 2 phases B A W1 C W2 Only 2 welders on each phase W3 20A + 20A = 40 Amps Per Phase Use for a ‘Ball Park’ figure in early planning stages. Table based on a temperate climate Office Floor area = 850m2 Light/Power = 50 VA/m2 Reverse cycle AC = 25 VA/m2 75 VA/m2 63.750kVA √3 x 400 = x 850 = 63.750kVA 92 Amps/Phase