26301-20 - Load Calculations

What is the minimum size conductor will be used for a 3∅,208v, 65A circuit at 350' to not exceed 3% VD?

#1 AWG

What is the minimum branch circuit conductor size for a 460v 30 hp 3∅ motor?

#6 AWG

What size branch circuit conductors will feed a A/C with a nameplate rating of 40A 240v 1∅

#6 AWG

According to NEC section 210.11(C)(2) & 210.52(F), How many circuits are required for each 120V 20A (calculated at 1500VA) laundry circuit?

1

How many VA do 8 receptacles have total?

1,440 VA

What is the derating factor of a 75℃ rated conductor in an ambient temperature of 58℉?

1.15

What is the square root of 3?

1.732

What percentage are Noncontinuous loads factored as?

100%

What percentage are Continuous loads factored as?

125%

How many duplex receptacles can be connected on a 20A 120v circuit

13

How many VA are required by 2020 NEC for lighting in a 10,500 sq. ft. library?

15,750 VA

What is the ampacity of a 480v 10.5 kW continuous load?

16 A

Based on 2020 NEC section 210.11(C)(1) & 210.52(B)(1), how many small appliance circuits are required for a 2,500 sq. ft. home?

2

What is the demand in kW for 5 dryers rated at 5,250 VA each?

22.31 kW

How long does a load operate to be determined continuous and what % is it figured at?

3 hours; 125%

What is the total VA for 5 heavy duty lamp holders as described by NEC section 220.14(E)?

3,000 VA

Using the CM formula, What % VD is present on a 1∅, 240v, 50A circuit using #4 CU for 250'?

3.21%

What NEC Table covers conductor adjustment factors for more than 3 conductors in a conduit?

310.15 (C)(1)

What NEC Table covers temperature correction factors based upon ambient temperatures higher than 30°C (86°F)

310.15(B)(1)

What NEC Table covers the ampacities of insulated conductors when not more than 3 current carrying conductors?

310.16

What NEC section covers fixed storage water heaters having 120 gallons or less?

422.13

What NEC article covers fixed electric heating equipment?

424

Based on the 2020 NEC, which table is used to determine ampacity for 3∅ motors?

430.250

What is the branch circuit rating for a 110-gallon hot water tank with a nameplate rating of 8,800 W ,240V

44.27 A

What NEC article covers Air Conditioning Leads?

460

How many 20A circuits does it take to feed 60' of heavy use Plugmold® as described by 220.14(H) and 3.1.0?

5

Based on 2002 NEC Table 310.15(C)(1), What is the adjustment factor for the 11 current carrying conductors in a raceway?

50

If a utilization equipment is fastened in place and connected to other loads, the fastened in place equipment cannot exceed _______ of the branch circuit ampere rating?

50%

What is the required circuit ampacity for a 5,400 W, 480 V, 3∅ load?

6.49 A

Based on the 2020 NEC, what section covers arc welders?

630 part II

What is the demand factor for 5 pieces of commercial cooking equipment?

70

What is NEC table 220.54?

Demand factors for electric clothes dryers

How can you determine Amperage from VA?

Divide VA by Voltage

True/False: 2020 NEC states it is a violation if a branch circuit exceeds 3%.

False

True/False: A continuous load is calculated by multiplying the total amperage by 1.732

False

True/False: Breaker size is the only determining factor for circuit sizing.

False

True/False: Commercial cooking equipment is figured the same as residential.

False

True/False: The % of full load current for a non-time delay fuse used with a Squirrel Cage motor design letter J is 175%.

False

True/False: The 2 in voltage drop formulas is the square reciprocal of 3.

False

True/False: The quantity column on Chapter 9 table 8 is for conductor quantity in raceways

False

True/False: The square root of three (1.732) is used on single phase equations.

False

True/False: Voltage drop is accounted for in all construction drawings and is the engineer's responsibility.

False

What is the difference between the single phase and three phase voltage drop formulas?

Single phase uses the number 2, three phase uses √3

True/False: 125% of a continuous load is the same as factoring the breaker at 80% capacity?

True

True/False: A continuous load is defined as a load that runs for 3 hours or more

True

True/False: K= the constant values of 12.9 for copper and 21.2 for aluminum.

True

True/False: The 60° column is used in table 310.16 to determine wire size up to 100A then switch to 75°.

True

True/False: The coated column in chapter 9 table 8 is for tinned wire.

True

True/False: You use the uncoated kFT column in chapter 9 table 8 for the resistance voltage drop formula

True

What is the following Formula: 2 x L x R x I / 1,000?

Voltage drop for single phase circuits using conductor resistance

What is the total ampacity of a 120v 1∅ circuit with 3 - 250 VA loads that run for 5 hours and 6- 2.5amp loads that run intermittently?

22.8 A

What NEC table is used for calculating lighting loads in non-dwelling occupancies, expressed as a units per square foot?

220.12

Using the 2020 NEC, which code section gives you the VA for a 120v receptacle?

220.14 (I)

What NEC section covers loads for recessed lighting fixtures?

220.14 (J)

What NEC Table covers the calculations of household cooking appliances

220.55

What NEC Table covers demand factors for commercial kitchen equipment?

220.56

What is the total load center length for the following loads- LOAD 1= 80'x 100A, LOAD 2= 75' x 150A, LOAD 3= 50' x 175A?

65.88'

How many VA does 45' of show window require as described by 220.14(G)?

720 VA

How many receptacles are required for 85' of show window?

8

What is the demand load for 1 range rated at 9kW?

8 kW

In the formula 2 x L x K x 1/CM, what does K stand for?

A mathematical constant for resistance depending on conductor material

How do you determine VA?

Both A & C

Which section in the 2020 NEC can you find the area of a conductor used for voltage drop?

Chapter 9 Table 8