1. Calculation Speed Drill #1
©Ted “Smitty” Smith 2008

2. Instructions
This speed drill is designed to help you practice calculations. The slides will transition in three and one half minutes instead of two minutes.
Attempt to answer the questions and then when the slide show completes, Check your answer. When you reach the end of the drill all of the slides will be repeated without the timer so you will have time to check and verify your answers at that time.
Click on the left mouse button to begin.

3. Conductor Ampacity
A 1/0 AWG THHN conductor installed in an ambient temperature of 103 degrees F. will have an ampacity of _________.
Copyright 2005 Ted "Smitty" Smith

4. Conductor Ampacity
Amperes

5. Conductor Ampacity
What is the ampacity of a 250 kCMIL aluminum THW conductor installed in an ambient temperature of 44 degrees Celsius?
Copyright 2005 Ted "Smitty" Smith

6. Conductor Amapacity
amperes

7. Box Fill
What is the volume allowance required for the following junction box which has a total of nine 12 AWG THHN conductors entering the junction box, one of which is an equipment grounding conductor. The box will contain one duplex receptacle, has no internal clamps, and no luminairie studs or hickeys.

8. Box Fill
24.75

9. Cooking Calculations
What is the demand on the main service entrance of a range that has a nameplate rating of 240V and 9.5 kW?

10. Cooking Calculations
8000 watts

11. Conductor Ampacity
A load of 23 amperes is being fed by a circuit consisting of 10 AWG THHN copper conductors. The conductors are installed in a conduit that is installed on a rooftop in the direct sunlight. The conduit is installed 12” above the roof from the bottom of the conduit. The average ambient temperature for the area in which the conduit is installed is 87 degrees F. The conduit contains a total of three current carrying conductors. Is this an acceptable installation?
Copyright 2005 Ted "Smitty" Smith

12. Conductor Ampacity
Yes, it is rated to carry 32.8 amperes.

13. Conductor Ampacity
A 39.6 ampere load is fed with a 6 AWG THW conductor that is installed in a conduit with a total of 7 current carrying conductors. The conduit is installed in a room that has an ambient temperature 38 degrees Celsius. Is this an acceptable installation?

14. Conductor Ampacity
Yes it is acceptable. The conductor is rated at amperes.

15. Raceway Fill
Three 10 AWG THHN, four 6 AWG THW and five 8 AWG TW conductors are installed in a one and one half inch electrical metallic tubing conduit that is 280 feet in length. Is this an acceptable installation?
Copyright 2005 Ted "Smitty" Smith

16. Raceway Fill
Yes, the wires make up a volume of and at 40% fill an EMT 1 1/4” conduit is
Copyright 2005 Ted "Smitty" Smith

17. Conductor Ampacity
What is the ampacity of 2 AWG TW aluminum conductor installed in a conduit that is installed in a boiler room with an ambient temperature of 103 degrees F and the conductor is installed in a conduit with a total of 17 current carrying conductors?

18. Conductor Amapacity
30.75 Amperes

19. Cooking Calculations
What is the demand on the main service entrance of a dwelling unit for a range that has a nameplate rating of 14.5 kW at 240 volts?

20. Cooking Calculations
9200 watts

21. Box Fill
A 4 x 1 ½ square metal box is installed with two duplex receptacles. The box has a total of three 12 AWG MC cables entering the box, each MC cable is a 12/2 with ground. The box contains no internal cable clamps, and no luminairie studs or hickeys. Is this an acceptable installation?

22. Box Fill
No, the conductors and devices require a volume allowance of and Table (A) lists a 4 x 1 ½” metal box as having a volume of 21.0

23. Raceway Fill
Is it allowable to add three 10 AWG THHN conductors to an existing conduit that is 150 feet in length and currently has eight 6 AWG THWN conductors and one 12 AWG THHN conductor installed? The conduit is a 1 ¼” inch electrical metallic tubing.

24. Raceway Fill
No. The total area used by the conductors once the three 10 AWG conductors are added will be inches and a 1 ¼” EMT at 40% fill has an allowance of only .598 inches.

25. Stop This is the end of the presentation.
You can now review the slides and answers without the timer.
Click the slide to advance to the next slide

26. Conductor Ampacity
A 1/0 AWG THHN conductor installed in an ambient temperature of 103 degrees F. will have an ampacity of _________.
Copyright 2005 Ted "Smitty" Smith

27. Conductor Ampacity
Amperes

28. Conductor Ampacity
What is the ampacity of a 250 kCMIL aluminum THW conductor installed in an ambient temperature of 44 degrees Celsius?
Copyright 2005 Ted "Smitty" Smith

29. Conductor Amapacity
amperes

30. Box Fill
What is the volume allowance required for the following junction box which has a total of nine 12 AWG THHN conductors entering the junction box, one of which is an equipment grounding conductor. The box will contain one duplex receptacle, has no internal clamps, and no luminairie studs or hickeys.

31. Box Fill
24.75

32. Cooking Calculations
What is the demand on the main service entrance of a range that has a nameplate rating of 240V and 9.5 kW?

33. Cooking Calculations
8000 watts

34. Conductor Ampacity
A load of 23 amperes is being fed by a circuit consisting of 10 AWG THHN copper conductors. The conductors are installed in a conduit that is installed on a rooftop in the direct sunlight. The conduit is installed 12” above the roof from the bottom of the conduit. The average ambient temperature for the area in which the conduit is installed is 87 degrees F. The conduit contains a total of three current carrying conductors. Is this an acceptable installation?
Copyright 2005 Ted "Smitty" Smith

35. Conductor Ampacity
Yes, it is rated to carry 32.8 amperes.

36. Conductor Ampacity
A 39.6 ampere load is fed with a 6 AWG THW conductor that is installed in a conduit with a total of 7 current carrying conductors. The conduit is installed in a room that has an ambient temperature 38 degrees Celsius. Is this an acceptable installation?

37. Conductor Ampacity
Yes it is acceptable. The conductor is rated at amperes.

38. Raceway Fill
Three 10 AWG THHN, four 6 AWG THW and five 8 AWG TW conductors are installed in a one and one half inch electrical metallic tubing conduit that is 280 feet in length. Is this an acceptable installation?
Copyright 2005 Ted "Smitty" Smith

39. Raceway Fill
Yes, the wires make up a volume of and at 40% fill an EMT 1 1/4” conduit is
Copyright 2005 Ted "Smitty" Smith

40. Conductor Ampacity
What is the ampacity of 2 AWG TW aluminum conductor installed in a conduit that is installed in a boiler room with an ambient temperature of 103 degrees F and the conductor is installed in a conduit with a total of 17 current carrying conductors?

41. Conductor Amapacity
30.75 Amperes

42. Cooking Calculations
What is the demand on the main service entrance of a dwelling unit for a range that has a nameplate rating of 14.5 kW at 240 volts?

43. Cooking Calculations
9200 watts

44. Box Fill
A 4 x 1 ½ square metal box is installed with two duplex receptacles. The box has a total of three 12 AWG MC cables entering the box, each MC cable is a 12/2 with ground. The box contains no internal cable clamps, and no luminairie studs or hickeys. Is this an acceptable installation?

45. Box Fill
No, the conductors and devices require a volume allowance of and Table (A) lists a 4 x 1 ½” metal box as having a volume of 21.0

46. Raceway Fill
Is it allowable to add three 10 AWG THHN conductors to an existing conduit that is 150 feet in length and currently has eight 6 AWG THWN conductors and one 12 AWG THHN conductor installed? The conduit is a 1 ¼” inch electrical metallic tubing.

47. Raceway Fill
No. The total area used by the conductors once the three 10 AWG conductors are added will be inches and a 1 ¼” EMT at 40% fill has an allowance of only .598 inches.