johnweaver
Member
A commercial building with two tennants. What is the service conductor load in amps?
Tennant 1
5100 square feet,
20kw heat at 240 volts,
0ne 2 hp 120 volt water pump,
12 amp refer,
4 kw hot water tank at 240 volts,
12 feet of show window lighting,
one 25 amp 240 volt AC unit,
24 duplex recepticals,
1500 va Microwave oven,
sign 1200 va
Tennant 2
23,300 square feet,
120 kw heat at 240 volts,
two 5 hp 120 volt motors,
one 1/2 hp 120 volt water pump,
12 amp refer,
4 kw hot water tank,
two 240 volt 32 amp rated transformer arc
welders at 50% duty cycle,
50 feet of show window lighting,
65 amp 240 volt AC unit,
one 10 hp 240 volt motor,
45 duplex recepticals,
1500 va microwave at 120 volts,
sign 1200va
Totals of both tennants
sq footage = 28,400 x 2va = 56,800 va
Heat = 20kw + 120kw = 140,000
A/C = 90 x 240 = 21,600 (omit)
Refer = 12 x 120 x 2 = 2,880
Hot water = 4000 x 2 = 8,000
Show window = 62 x 200va = 12,400
Receptical 69 x 180va = 12,420va
12,420 - 10,000 x 50% + 10,000 = 11,210
Microwave = 1500va x 2 = 3,000
Sign = 1200 x 2 = 2,400
Welders = 2 x 32 x 240 x .71 = 10,906
Table 630.31 50% duty cycle
Motors
one 2hp 120v (24 FLA x 120)= 2,880
two 5hp 120v (56 FLA x 2 x 120) = 13,440
one 1/2hp 120v (9.8 FLA x 120) = 1,176
one 10hp 240v (50 FLA x 240) = 12,000
25% Lgst mtr. 10hp (12000 x .25) = 3000
Total = 280,092 va
280,092 / 240 = 1,167 amps
This is the answer I come up with but it dosn't match any of the answers given to choose from.
What am I doing wrong?
Thanks John
Tennant 1
5100 square feet,
20kw heat at 240 volts,
0ne 2 hp 120 volt water pump,
12 amp refer,
4 kw hot water tank at 240 volts,
12 feet of show window lighting,
one 25 amp 240 volt AC unit,
24 duplex recepticals,
1500 va Microwave oven,
sign 1200 va
Tennant 2
23,300 square feet,
120 kw heat at 240 volts,
two 5 hp 120 volt motors,
one 1/2 hp 120 volt water pump,
12 amp refer,
4 kw hot water tank,
two 240 volt 32 amp rated transformer arc
welders at 50% duty cycle,
50 feet of show window lighting,
65 amp 240 volt AC unit,
one 10 hp 240 volt motor,
45 duplex recepticals,
1500 va microwave at 120 volts,
sign 1200va
Totals of both tennants
sq footage = 28,400 x 2va = 56,800 va
Heat = 20kw + 120kw = 140,000
A/C = 90 x 240 = 21,600 (omit)
Refer = 12 x 120 x 2 = 2,880
Hot water = 4000 x 2 = 8,000
Show window = 62 x 200va = 12,400
Receptical 69 x 180va = 12,420va
12,420 - 10,000 x 50% + 10,000 = 11,210
Microwave = 1500va x 2 = 3,000
Sign = 1200 x 2 = 2,400
Welders = 2 x 32 x 240 x .71 = 10,906
Table 630.31 50% duty cycle
Motors
one 2hp 120v (24 FLA x 120)= 2,880
two 5hp 120v (56 FLA x 2 x 120) = 13,440
one 1/2hp 120v (9.8 FLA x 120) = 1,176
one 10hp 240v (50 FLA x 240) = 12,000
25% Lgst mtr. 10hp (12000 x .25) = 3000
Total = 280,092 va
280,092 / 240 = 1,167 amps
This is the answer I come up with but it dosn't match any of the answers given to choose from.
What am I doing wrong?
Thanks John