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Generator Size worksheet

Grade 4 · CCSS 4.OA.A.3

Solve each problem and show your work. Round answers to 2 decimal places where needed.

1.
Problem 1.
- Refrigerator or freezer: Yes
- Refrigerator or freezer: running watts: 600 W
- Refrigerator or freezer: additional starting watts: 1,800 W
- Sump pump (1/2 hp): Yes
- Sump pump (1/2 hp): running watts: 1,200 W
- Sump pump (1/2 hp): additional starting watts: 875 W
- Furnace fan (1/2 hp): Yes
- Furnace fan (1/2 hp): running watts: 650 W
- Furnace fan (1/2 hp): additional starting watts: 900 W
- Lights (LED, several rooms): Yes
- Lights (LED, several rooms): running watts: 210 W
- Lights (LED, several rooms): additional starting watts: 0 W
- TV, internet router and phone chargers: Yes
- TV, internet router and phone chargers: running watts: 360 W
- TV, internet router and phone chargers: additional starting watts: 0 W
- Well pump (1/2 hp): No
- Window air conditioner (10,000 BTU): No
- Microwave (1,000 W): No
- Space heater: No
- Other appliance: No
- Headroom on the running load: 24%
Find: Starting (peak) watts needed
Answer
2.
Problem 2.
- Refrigerator or freezer: Yes
- Refrigerator or freezer: running watts: 625 W
- Refrigerator or freezer: additional starting watts: 1,200 W
- Sump pump (1/2 hp): Yes
- Sump pump (1/2 hp): running watts: 860 W
- Sump pump (1/2 hp): additional starting watts: 1,300 W
- Furnace fan (1/2 hp): Yes
- Furnace fan (1/2 hp): running watts: 800 W
- Furnace fan (1/2 hp): additional starting watts: 2,000 W
- Lights (LED, several rooms): Yes
- Lights (LED, several rooms): running watts: 230 W
- Lights (LED, several rooms): additional starting watts: 0 W
- TV, internet router and phone chargers: Yes
- TV, internet router and phone chargers: running watts: 360 W
- TV, internet router and phone chargers: additional starting watts: 0 W
- Well pump (1/2 hp): No
- Window air conditioner (10,000 BTU): No
- Microwave (1,000 W): No
- Space heater: No
- Other appliance: No
- Headroom on the running load: 22%
Find: Starting (peak) watts needed
Answer
3.
Problem 3.
- Refrigerator or freezer: Yes
- Refrigerator or freezer: running watts: 850 W
- Refrigerator or freezer: additional starting watts: 1,200 W
- Sump pump (1/2 hp): Yes
- Sump pump (1/2 hp): running watts: 1,125 W
- Sump pump (1/2 hp): additional starting watts: 1,350 W
- Furnace fan (1/2 hp): Yes
- Furnace fan (1/2 hp): running watts: 800 W
- Furnace fan (1/2 hp): additional starting watts: 1,375 W
- Lights (LED, several rooms): Yes
- Lights (LED, several rooms): running watts: 130 W
- Lights (LED, several rooms): additional starting watts: 0 W
- TV, internet router and phone chargers: Yes
- TV, internet router and phone chargers: running watts: 280 W
- TV, internet router and phone chargers: additional starting watts: 0 W
- Well pump (1/2 hp): No
- Window air conditioner (10,000 BTU): No
- Microwave (1,000 W): No
- Space heater: No
- Other appliance: No
- Headroom on the running load: 18%
Find: Starting (peak) watts needed
Answer
4.
Problem 4.
- Refrigerator or freezer: Yes
- Refrigerator or freezer: running watts: 800 W
- Refrigerator or freezer: additional starting watts: 1,400 W
- Sump pump (1/2 hp): Yes
- Sump pump (1/2 hp): running watts: 900 W
- Sump pump (1/2 hp): additional starting watts: 1,300 W
- Furnace fan (1/2 hp): Yes
- Furnace fan (1/2 hp): running watts: 700 W
- Furnace fan (1/2 hp): additional starting watts: 1,600 W
- Lights (LED, several rooms): Yes
- Lights (LED, several rooms): running watts: 200 W
- Lights (LED, several rooms): additional starting watts: 0 W
- TV, internet router and phone chargers: Yes
- TV, internet router and phone chargers: running watts: 225 W
- TV, internet router and phone chargers: additional starting watts: 0 W
- Well pump (1/2 hp): No
- Window air conditioner (10,000 BTU): No
- Microwave (1,000 W): No
- Space heater: No
- Other appliance: No
- Headroom on the running load: 20%
Find: Starting (peak) watts needed
Answer
5.
Problem 5.
- Refrigerator or freezer: Yes
- Refrigerator or freezer: running watts: 640 W
- Refrigerator or freezer: additional starting watts: 1,400 W
- Sump pump (1/2 hp): Yes
- Sump pump (1/2 hp): running watts: 1,100 W
- Sump pump (1/2 hp): additional starting watts: 1,200 W
- Furnace fan (1/2 hp): Yes
- Furnace fan (1/2 hp): running watts: 650 W
- Furnace fan (1/2 hp): additional starting watts: 1,000 W
- Lights (LED, several rooms): Yes
- Lights (LED, several rooms): running watts: 200 W
- Lights (LED, several rooms): additional starting watts: 0 W
- TV, internet router and phone chargers: Yes
- TV, internet router and phone chargers: running watts: 300 W
- TV, internet router and phone chargers: additional starting watts: 0 W
- Well pump (1/2 hp): No
- Window air conditioner (10,000 BTU): No
- Microwave (1,000 W): No
- Space heater: No
- Other appliance: No
- Headroom on the running load: 16%
Find: Starting (peak) watts needed
Answer
6.
Problem 6.
- Refrigerator or freezer: Yes
- Refrigerator or freezer: running watts: 600 W
- Refrigerator or freezer: additional starting watts: 1,650 W
- Sump pump (1/2 hp): Yes
- Sump pump (1/2 hp): running watts: 860 W
- Sump pump (1/2 hp): additional starting watts: 1,250 W
- Furnace fan (1/2 hp): Yes
- Furnace fan (1/2 hp): running watts: 980 W
- Furnace fan (1/2 hp): additional starting watts: 1,300 W
- Lights (LED, several rooms): Yes
- Lights (LED, several rooms): running watts: 210 W
- Lights (LED, several rooms): additional starting watts: 0 W
- TV, internet router and phone chargers: Yes
- TV, internet router and phone chargers: running watts: 340 W
- TV, internet router and phone chargers: additional starting watts: 0 W
- Well pump (1/2 hp): No
- Window air conditioner (10,000 BTU): No
- Microwave (1,000 W): No
- Space heater: No
- Other appliance: No
- Headroom on the running load: 16%
Find: Starting (peak) watts needed
Answer
7.
Problem 7.
- Refrigerator or freezer: Yes
- Refrigerator or freezer: running watts: 680 W
- Refrigerator or freezer: additional starting watts: 1,000 W
- Sump pump (1/2 hp): Yes
- Sump pump (1/2 hp): running watts: 1,300 W
- Sump pump (1/2 hp): additional starting watts: 1,300 W
- Furnace fan (1/2 hp): Yes
- Furnace fan (1/2 hp): running watts: 750 W
- Furnace fan (1/2 hp): additional starting watts: 900 W
- Lights (LED, several rooms): Yes
- Lights (LED, several rooms): running watts: 160 W
- Lights (LED, several rooms): additional starting watts: 0 W
- TV, internet router and phone chargers: Yes
- TV, internet router and phone chargers: running watts: 375 W
- TV, internet router and phone chargers: additional starting watts: 0 W
- Well pump (1/2 hp): No
- Window air conditioner (10,000 BTU): No
- Microwave (1,000 W): No
- Space heater: No
- Other appliance: No
- Headroom on the running load: 18%
Find: Starting (peak) watts needed
Answer
8.
Problem 8.
- Refrigerator or freezer: Yes
- Refrigerator or freezer: running watts: 780 W
- Refrigerator or freezer: additional starting watts: 1,500 W
- Sump pump (1/2 hp): Yes
- Sump pump (1/2 hp): running watts: 1,300 W
- Sump pump (1/2 hp): additional starting watts: 1,150 W
- Furnace fan (1/2 hp): Yes
- Furnace fan (1/2 hp): running watts: 880 W
- Furnace fan (1/2 hp): additional starting watts: 1,275 W
- Lights (LED, several rooms): Yes
- Lights (LED, several rooms): running watts: 180 W
- Lights (LED, several rooms): additional starting watts: 0 W
- TV, internet router and phone chargers: Yes
- TV, internet router and phone chargers: running watts: 360 W
- TV, internet router and phone chargers: additional starting watts: 0 W
- Well pump (1/2 hp): No
- Window air conditioner (10,000 BTU): No
- Microwave (1,000 W): No
- Space heater: No
- Other appliance: No
- Headroom on the running load: 14%
Find: Starting (peak) watts needed
Answer
9.
Problem 9.
- Refrigerator or freezer: Yes
- Refrigerator or freezer: running watts: 800 W
- Refrigerator or freezer: additional starting watts: 1,500 W
- Sump pump (1/2 hp): Yes
- Sump pump (1/2 hp): running watts: 1,350 W
- Sump pump (1/2 hp): additional starting watts: 1,250 W
- Furnace fan (1/2 hp): Yes
- Furnace fan (1/2 hp): running watts: 1,050 W
- Furnace fan (1/2 hp): additional starting watts: 1,200 W
- Lights (LED, several rooms): Yes
- Lights (LED, several rooms): running watts: 200 W
- Lights (LED, several rooms): additional starting watts: 0 W
- TV, internet router and phone chargers: Yes
- TV, internet router and phone chargers: running watts: 340 W
- TV, internet router and phone chargers: additional starting watts: 0 W
- Well pump (1/2 hp): No
- Window air conditioner (10,000 BTU): No
- Microwave (1,000 W): No
- Space heater: No
- Other appliance: No
- Headroom on the running load: 17%
Find: Starting (peak) watts needed
Answer
10.
Problem 10.
- Refrigerator or freezer: Yes
- Refrigerator or freezer: running watts: 725 W
- Refrigerator or freezer: additional starting watts: 1,500 W
- Sump pump (1/2 hp): Yes
- Sump pump (1/2 hp): running watts: 950 W
- Sump pump (1/2 hp): additional starting watts: 1,500 W
- Furnace fan (1/2 hp): Yes
- Furnace fan (1/2 hp): running watts: 800 W
- Furnace fan (1/2 hp): additional starting watts: 1,500 W
- Lights (LED, several rooms): Yes
- Lights (LED, several rooms): running watts: 150 W
- Lights (LED, several rooms): additional starting watts: 0 W
- TV, internet router and phone chargers: Yes
- TV, internet router and phone chargers: running watts: 340 W
- TV, internet router and phone chargers: additional starting watts: 0 W
- Well pump (1/2 hp): No
- Window air conditioner (10,000 BTU): No
- Microwave (1,000 W): No
- Space heater: No
- Other appliance: No
- Headroom on the running load: 25%
Find: Starting (peak) watts needed
Answer

Answer key: Generator Size worksheet

1. Starting (peak) watts needed: 4,820 W
1. Add the running watts of everything that may be on at once, since they all draw power together
  $600 + 1,200 + 650 + 210 + 360$ $= 3,020 W$
2. Find the biggest start-up burst: the refrigerator or freezer needs 1,800 W extra for a moment as it starts
  $1,800 W$
3. Peak load: add the one biggest start-up burst, since motors rarely start at the same time
  $3,020 + 1,800$ $= 4,820 W$
4. Add 24% headroom (spare room) so the generator is not run at its limit. This is its running (rated) watts
  $3,020 \times 1.24$ $= 3,744.8 W$
2. Starting (peak) watts needed: 4,875 W
1. Add the running watts of everything that may be on at once, since they all draw power together
  $625 + 860 + 800 + 230 + 360$ $= 2,875 W$
2. Find the biggest start-up burst: the furnace fan (1/2 hp) needs 2,000 W extra for a moment as it starts
  $2,000 W$
3. Peak load: add the one biggest start-up burst, since motors rarely start at the same time
  $2,875 + 2,000$ $= 4,875 W$
4. Add 22% headroom (spare room) so the generator is not run at its limit. This is its running (rated) watts
  $2,875 \times 1.22$ $= 3,507.5 W$
3. Starting (peak) watts needed: 4,560 W
1. Add the running watts of everything that may be on at once, since they all draw power together
  $850 + 1,125 + 800 + 130 + 280$ $= 3,185 W$
2. Find the biggest start-up burst: the furnace fan (1/2 hp) needs 1,375 W extra for a moment as it starts
  $1,375 W$
3. Peak load: add the one biggest start-up burst, since motors rarely start at the same time
  $3,185 + 1,375$ $= 4,560 W$
4. Add 18% headroom (spare room) so the generator is not run at its limit. This is its running (rated) watts
  $3,185 \times 1.18$ $= 3,758.3 W$
4. Starting (peak) watts needed: 4,425 W
1. Add the running watts of everything that may be on at once, since they all draw power together
  $800 + 900 + 700 + 200 + 225$ $= 2,825 W$
2. Find the biggest start-up burst: the furnace fan (1/2 hp) needs 1,600 W extra for a moment as it starts
  $1,600 W$
3. Peak load: add the one biggest start-up burst, since motors rarely start at the same time
  $2,825 + 1,600$ $= 4,425 W$
4. Add 20% headroom (spare room) so the generator is not run at its limit. This is its running (rated) watts
  $2,825 \times 1.2$ $= 3,390 W$
5. Starting (peak) watts needed: 4,290 W
1. Add the running watts of everything that may be on at once, since they all draw power together
  $640 + 1,100 + 650 + 200 + 300$ $= 2,890 W$
2. Find the biggest start-up burst: the refrigerator or freezer needs 1,400 W extra for a moment as it starts
  $1,400 W$
3. Peak load: add the one biggest start-up burst, since motors rarely start at the same time
  $2,890 + 1,400$ $= 4,290 W$
4. Add 16% headroom (spare room) so the generator is not run at its limit. This is its running (rated) watts
  $2,890 \times 1.16$ $= 3,352.4 W$
6. Starting (peak) watts needed: 4,640 W
1. Add the running watts of everything that may be on at once, since they all draw power together
  $600 + 860 + 980 + 210 + 340$ $= 2,990 W$
2. Find the biggest start-up burst: the refrigerator or freezer needs 1,650 W extra for a moment as it starts
  $1,650 W$
3. Peak load: add the one biggest start-up burst, since motors rarely start at the same time
  $2,990 + 1,650$ $= 4,640 W$
4. Add 16% headroom (spare room) so the generator is not run at its limit. This is its running (rated) watts
  $2,990 \times 1.16$ $= 3,468.4 W$
7. Starting (peak) watts needed: 4,565 W
1. Add the running watts of everything that may be on at once, since they all draw power together
  $680 + 1,300 + 750 + 160 + 375$ $= 3,265 W$
2. Find the biggest start-up burst: the sump pump (1/2 hp) needs 1,300 W extra for a moment as it starts
  $1,300 W$
3. Peak load: add the one biggest start-up burst, since motors rarely start at the same time
  $3,265 + 1,300$ $= 4,565 W$
4. Add 18% headroom (spare room) so the generator is not run at its limit. This is its running (rated) watts
  $3,265 \times 1.18$ $= 3,852.7 W$
8. Starting (peak) watts needed: 5,000 W
1. Add the running watts of everything that may be on at once, since they all draw power together
  $780 + 1,300 + 880 + 180 + 360$ $= 3,500 W$
2. Find the biggest start-up burst: the refrigerator or freezer needs 1,500 W extra for a moment as it starts
  $1,500 W$
3. Peak load: add the one biggest start-up burst, since motors rarely start at the same time
  $3,500 + 1,500$ $= 5,000 W$
4. Add 14% headroom (spare room) so the generator is not run at its limit. This is its running (rated) watts
  $3,500 \times 1.14$ $= 3,990 W$
9. Starting (peak) watts needed: 5,240 W
1. Add the running watts of everything that may be on at once, since they all draw power together
  $800 + 1,350 + 1,050 + 200 + 340$ $= 3,740 W$
2. Find the biggest start-up burst: the refrigerator or freezer needs 1,500 W extra for a moment as it starts
  $1,500 W$
3. Peak load: add the one biggest start-up burst, since motors rarely start at the same time
  $3,740 + 1,500$ $= 5,240 W$
4. Add 17% headroom (spare room) so the generator is not run at its limit. This is its running (rated) watts
  $3,740 \times 1.17$ $= 4,375.8 W$
10. Starting (peak) watts needed: 4,465 W
1. Add the running watts of everything that may be on at once, since they all draw power together
  $725 + 950 + 800 + 150 + 340$ $= 2,965 W$
2. Find the biggest start-up burst: the refrigerator or freezer needs 1,500 W extra for a moment as it starts
  $1,500 W$
3. Peak load: add the one biggest start-up burst, since motors rarely start at the same time
  $2,965 + 1,500$ $= 4,465 W$
4. Add 25% headroom (spare room) so the generator is not run at its limit. This is its running (rated) watts
  $2,965 \times 1.25$ $= 3,706.25 W$