Errata

Errata

2016 Printings:


On Pg 34 Figure 33 should say:

“Figure 33 – Circuit for Example 17 with values”

On pages 37&38, (Vbaseold/Vbasenew) should be written in units of KV.

Ex 18 should say: If the low-side transformer ratings are chosen as the base values in the generator circuit, find the base values and per unit quantities for the system in the diagram.

Ex. 29 should say:

What is the synchronous speed of an induction motor with 2 poles per phase and a frequency of 60 hz?

Ex. 31


On ex. 32:

Page 99 – There are two definitions that say Static Var Compensators. The first should say Synchronous Condenser.

Errata - Jan 2015 Printing:


Important!

There is an error in the PT section of the book that will be corrected in the next printing:

There is a Copy & Paste error. Where it says:

“Just as in CTs, never open the secondary of a PT while current is flowing in the primary circuit, as large periodic secondary voltages develop during periods of flux change. Because of this, if a meter or relay secondary circuit of a PT must be disconnected, you must first short-circuit the secondary winding, and then remove the component. The short across the secondary winding may be removed after the secondary circuit is closed”

This is incorrect information.

While the secondary winding may seem to be isolated from the primary winding, There may be large voltages built up due to the distributed capacitance. Never short circuit the secondary winding. As this may lead to a fatal shock.

P 4 The RMS formula should be:

P 8 ex. 2, The concepts shown in this problem are correct. However for this size load & generator, we should be using a three phase solution:

P 9, Ex 2.

Vp should be as follows:

P 19

On page 21, I should have been more specific on my formulas:

P 23 334.49 should be in VA, not W

Calculation should say 87.34 angle -11.3 V (not Amps)

P 26 ex. 12 Power should be in KW not KVA

P45 The dot on the secondary coil for the subtractive polarity diagram should be on the lower right.

P 49 - Ex. 22 Should say 4% - 0.3 = 3.7%, So the range will be 3.7% to 4.3%

P 54 It should say:

P 60

P 65 Ex 30.

Coil pitch = 20 deg X 8 = 160 deg

P 69 Ex. 31 The final answers are correct but the lagging pf angle should be +35.9 deg, the leading pf angle should be -35.9deg.

P 71 Ex. 32b is incomplete:


P 81. Use THHN CU wire. It should be 28A X 125% (for cont motor loads) = 35A

P 127 I missed the generator impedance on this one. The positive sequence impedance should be 0.2 + j0.546 instead of 0.2 + 0.466

Join Our E-News List

Contact Us

Questions? Feedback? Feel free to reach out to us via email: This email address is being protected from spambots. You need JavaScript enabled to view it.