Two Minute Drill #9 Copyright 2005 Ted "Smitty" Smith.

 Left click on the presentation ICON located at the bottom of the slide directory to the left of the this slide.  Each slide will transition to the correct answer automatically in 3:30 minutes. The correct answer will transition in 10 seconds. You may also left click on the slide to manually transition.  Do not worry about writing down the correct answer for now. You will have the opportunity to do that at the end of the two minute drill  Good luck  Remember to start the slide show to activate the timer. Copyright 2005 Ted "Smitty" Smith

 This drill is calculations only.  Concentrate on the correct answer not on the speed.  Remember do not worry about writing down the right answer for now. When you reach the end all of the slides will be repeated without the timer so you can take your time to find the ones you missed and write down the correct answers then.  Click on the slide to proceed. Copyright 2005 Ted "Smitty" Smith

 What is the minimum/ maximum overload relay range that would be allowed for a 230 volt, single phase AC motor that is rated at 2 horsepower and a marked temperature rise of 30 degrees Celsius?  15a-16.8a  20a-22a  12a-14a  12a-15a Copyright 2005 Ted "Smitty" Smith

 What is the minimum required length of a pull box that is placed between two 4” EMT conduits? The conduits will enter on either end and the wires will pull straight through the box. The conduits will contain six #1 THHN conductors, three #4 THW conductors and fifteen #12 THHN conductors. In addition a #4 ground conductor will be run in the conduits. The ground conductor will be THHN.  22”  18”  32”  24” Copyright 2005 Ted "Smitty" Smith

 What is the minimum required service for a single family dwelling that is 1100 square feet and is equipped with 12kw range, a 4.2kw water heater and 8.6kw of fixed electric heat? The house also has a 1.1kw dishwasher and a.75kw garbage disposal. The house is fed by a 230v, single phase service.  110a  125a  119.64a  120a Copyright 2005 Ted "Smitty" Smith

 What is the minimum sized THHN conductor that can be used to feed a set of non-motor generator arc welders? The set is made up of four arc welders that have I 1eff ratings of 40a, 50a, 65a and 75a. The termination lugs are rated at 75 degrees Celsius and the over current device is rated at 90 degrees Celsius.  4/0  2/0  3/0  1/0 Copyright 2005 Ted "Smitty" Smith

 What is the minimum sized THHN conductor that can be used on a branch circuit with a load of 42 amps? The load is a single motor for a control servo on a crane. The motor is designed to operate no more than 30 minutes at a time. The crane is permanently in place and is expected to operate at an ambient temperature of 46 degrees Celsius. The termination lugs are rated for 75 degrees Celsius.   6 awg  4 awg  8 awg  10 awg Copyright 2005 Ted "Smitty" Smith

 What is the minimum sized neutral that can be used for the service entrance for a single family dwelling that is 56’ x 125’. The home is equipped with a 16.8kw range, 230v, 4.6kw dryer, 230v, a 1.2 kw dishwasher and a.89 kw garbage disposal.  6 awg  3 awg  1/0 awg  2 awg Copyright 2005 Ted "Smitty" Smith

 If six #14 TW conductors at.0319 square inches each, and eight number 8 THWN conductors were installed in an 18” conduit between two cabinets, the minimum sized PVC, schedule 80 conduit, permitted by the NEC would be __________.  A. ¾”  B. 1”  C. 1 ¼”  D. 1 ½” Copyright 2005 Ted "Smitty" Smith

 What is the minimum required service for a dwelling that is 1000sf and is equipped with two wall a mounted ovens each rated at 240v and 25 amps and one cooktop rated at 240v and 20 amps. It also has 1.2kw dishwasher?  110a  125a  75a  100a Copyright 2005 Ted "Smitty" Smith

 What is the minimum sized 480v, three phase service that would be required for a commercial restaurant that is 18,000 square feet and equipped with 110 receptacle outlets, 150 feet of non-simultaneous 3000 series wire mold, 2000 VA lighted sign circuit, 300 ft of decorative track lighting, two 19.6kw ovens, three 9.2 kw grills, a 9.8kw walk in freezer, a 7.2 kw walk in refrigerator, two 5.9 kw deep fryers, a 4.2 kw ventilated cooking hood and a 480v, three phase, 7.5 hp squirrel cage motor for the RTU for HVAC purposes.  225a  205a  200a  150a Copyright 2005 Ted "Smitty" Smith

 What is the minimum sized schedule 80, rigid nonmetallic conduit that could be used for a branch circuit requiring 11 phase conductors and 4 neutral conductors and one ground conductor? The phase conductors will all be #10 THHN, the neutral conductors will all be #8 THHN and the ground conductor will be #12 THW. The conduit will be run ¾ of its distance underground and approximately ¼ of its distance encased in 6 inches of hardened concrete with sand under-footing.  1”  2”  1 ¼”  1 ½” Copyright 2005 Ted "Smitty" Smith

 What is the ampacity for each conductor when a raceway contains nine No. 4 THW copper current carrying conductors that are installed in a room with an ambient temperature of 96 degrees F?  70 amperes  85 amperes  59.5 amperes  52.36 amperes Copyright 2005 Ted "Smitty" Smith

 A 480 volt three phase motor that has a nameplate FLC of 52 amps will require what sized minimum overload protection? The motor also has a marked service factor of 2.0.  65 ampere  59.8 ampere  67.6 ampere  72.8 ampere Copyright 2005 Ted "Smitty" Smith

 What is the minimum size copper grounding electrode conductor required for a 120/208 volt, 3 phase 4 wire service using three No. 250 kcmil copper conductors per phase?  #2 AWG  1/0 AWG  2/0 AWG  3/0 AWG Copyright 2005 Ted "Smitty" Smith

 What is the minimum sized service that would be required for the following school using the optional method of calculation. The school is fed with a 480 volt, 3-phase service. It is 120,000 square feet and has a total connected load of 4,752,000-volt amps.  1500 ampere  5000 ampere  3000 ampere  6000 ampere Copyright 2005 Ted "Smitty" Smith

 What is the total demand of the kitchen equipment in a restaurant that is 3000 sf and is equipped with a 19.6 kw oven, a 22.6 kw oven, a 4.9 kw grill, a 9.7 kw grill, two 5.8 kw fryers, a 11.9 kw walk in freezer, a 11,6 kw walking refrigerator, a 9.6 kw ventilated cooking hood with environmental control. A 6.7 kw dishwasher and a 4.7 kw dough kneader.  42200 VA  73385 VA  67145 VA  55000 VA Copyright 2005 Ted "Smitty" Smith

 What is total demand on the main service entrance for a single range in a single family dwelling that has a nameplate rating of 19.6 kw?  19600 VA  12000 VA  11200 VA  10800 VA Copyright 2005 Ted "Smitty" Smith

 What is the average locked rotor current of a three phase motor with a design letter K and a nameplate rating of 15 hp? The motor is operating at 480 volts three phase.  265.63 a  21 a  169 a  153.36 Copyright 2005 Ted "Smitty" Smith

 Each of the slides will now be repeated.  They are not timed in this segment. To change a slide, click on the side with your left mouse button.  Be sure to physically look up the answers in your code book to improve your look up speed and skill. Copyright 2005 Ted "Smitty" Smith

 What is the minimum/ maximum overload relay range that would be allowed for a 230 volt, single phase AC motor that is rated at 2 horsepower and a marked temperature rise of 30 degrees Celsius?  15a-16.8a  20a-22a  12a-14a  12a-15a Copyright 2005 Ted "Smitty" Smith

 What is the minimum required length of a pull box that is placed between two 4” EMT conduits? The conduits will enter on either end and the wires will pull straight through the box. The conduits will contain six #1 THHN conductors, three #4 THW conductors and fifteen #12 THHN conductors. In addition a #4 ground conductor will be run in the conduits. The ground conductor will be THHN.  22”  18”  32”  24” Copyright 2005 Ted "Smitty" Smith

 What is the minimum required service for a single family dwelling that is 1100 square feet and is equipped with 12kw range, a 4.2kw water heater and 8.6kw of fixed electric heat? The house also has a 1.1kw dishwasher and a.75kw garbage disposal. The house is fed by a 230v, single phase service.  110a  125a  119.64a  120a Copyright 2005 Ted "Smitty" Smith

 What is the minimum sized THHN conductor that can be used to feed a set of non-motor generator arc welders? The set is made up of four arc welders that have I 1eff ratings of 40a, 50a, 65a and 75a. The termination lugs are rated at 75 degrees Celsius and the over current device is rated at 90 degrees Celsius.  4/0  2/0  3/0  1/0 Copyright 2005 Ted "Smitty" Smith

 hat is the minimum sized THHN conductor that can be used on a branch circuit with a load of 42 amps? The load is a single motor for a control servo on a crane. The motor is designed to operate no more than 30 minutes at a time. The crane is permanently in place and is expected to operate at an ambient temperature of 46 degrees Celsius. The termination lugs are rated for 75 degrees Celsius.   6 awg  4 awg  8 awg  10 awg Copyright 2005 Ted "Smitty" Smith