Exam (elaborations)
26401 Load And Feeder Calculations: Q’s And A’s (A+)
- Course
- Institution
26401 Load And Feeder Calculations: Q’s And A’s (A+)
[Show more]
Content preview
26401 Load And Feeder Calculations: Q’s And A’s (A+)What is the minimum demand required for the portion of a feeder that
supplies 30ft of show window? Right Ans - NEC 220.43 (A) Show windows
30ft x 200va = 6000 va
Residential Small apliance circuits must be rated at __________ per NEC
220.52(A) Right Ans - 1500 va
When performing load calculations for farm buildings the load that must be
included in the calculation at 100% demand must be at least _______ . Right
Ans - 60 amps
The demand lighting load for a 20,000 square foot motel with no dining room
or ballroom is ____ per NEC 220.12 and 220.42 Right Ans - 220. 14(M) 1.7
volt amperes per square foot. 18,000 va
What is the demand lighting load for a 100,000 square foot hotel with no
dining room or ballroom is ____ per 220.12 and 220.42 ? Right Ans - 72,000
va
When calculating the feeder load for a motor Control Center supplying several
Motors per 430.24 you must ______ . Right Ans - Determine the sum of all
the motor loads plus 25% of the largest motor.
A commercial kitchen with six or more pieces of kitchen equipment is subject
to a demand factor of ___________ per NEC table 220.56. Right Ans - 65%
demand factor
What is a tap conductor? Right Ans - When the overcurrent protection for a
conductor is located on the load side rather than the supply side of a
conductor, it is considered to be a tap conductor
What is the minimum general lighting load in volt-amps per square foot
required by the NEC table 220.12 for a store? Right Ans - 3va per s.f.
What is the total load center length for a tapped feeder with loads of 120a at
50 feet, 110a at 60 feet, 75a and 90 feet, and 70 amps at 150 feet? Right
Ans - •120a x 50ft = 6000
, •110a x 60ft = 6600
•75a x 90ft = 6750
•70a x 150ft = 10,500
•6000+6600+6750+10,500 = 29,850
•120a+110a+75a+70a = 375a
•29,a = 79.6 ft load center length
The minimum ampacity for a feeder supplying ten 30a shore power
receptacles in a marina is _____ per NEC table 555.12 Right Ans - •Table
555.12
•9-14 receptacles @ 80%
•10 receptacles x 30a = 300a
•Apply the demand factor from 555.12 300a x 80% = 240a
The minimum ampacity for a feeder supplying (30) shore power receptacles
in a marina each rated at 30a is _____ per NEC table 555.12. Right Ans -
•Table 555.12
•15-30 receptacles @ 70%
•30 receptacles x 30a = 900a
•Apply the demand factor from 555.12 900a x 70% = 630a
•What is the total load for a feeder serving
•(4) 2 horsepower motors 7.5a
•(3) 5 horsepower Motors16.7a
•(1) 15 horsepower 46.2a motor
•(1) 25 horsepower motor ? 74.8a
•(all Motors are 208 volts) Right Ans - •Use Table 430.250
•7.5 amps x 4 = 30a
•16.7amps x 3 = 50.1a
• 46.2 amps x 1= 46.2a
• 74.8 amps x 100% = 74.8
•74.8a x .25% = 18.7a (add additional 25% for largest motor load)
•30+50.1+46.2+74.8+18.7=219.8a or 30+50.1+46.2+93.5 = 219.8a
What is the feeder ampacity for a three phase, 120/208 Volt subpanel with a
connected load of 84,563 Volt amps? Right Ans - •84,563 va / 208volts =
406.5522
•Don't forget it's three phase! = 1.732
•406..732 = 234.89a
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller LeCrae. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67163 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now