A review of The Home Inspection Book by Marcia Darvin Spada

ISBN: 0324143842

 

Reviewed by Arlene Puentes of October Home Inspections.

 

In the table that follows you will find some of the errors and examples of confusing writing which can be found in Chapter 9 of The Home Inspection Book by Marcia Darvin Spada.

 

Although my limited schedule prohibits me from doing so, I could have created a longer table for Chapter 9 and can create similar tables for the rest of the chapters in this error-filled book.

 

Giving incorrect information to students of the home inspection profession is a serious offense. Home inspectors are charged with giving their clients accurate and objective information and a home inspector's consultation is used to make important decisions about financial matters and matters of safety.

 

In particular, misinformation about electrical components is not simply being fussy. The electrical system involves adequacy concerns (a possible major expense), and safety concerns (fire, shock, electrocution hazards) which need to be addressed as accurately and thoroughly as possible.

 

This table has been reviewed by my professional peers for accuracy and I welcome additional comments from my readers and from the author and/or publisher of this book.

 

Please  contact me with questions and comments, ap@octoberhome.com and (845) 339-7984.

 

 

Page 218

In the "You Should Know"  box:

"A watt is one ampere (discussed later)."

This is wrong. A watt is a unit of measurement. It is used to measure electrical work. The relationship between a watt and an ampere is found in Ohms Law. Specifically it is EI=W. That is, voltage times amperage equals a watt.

Page 218

"The voltage coming in from the transformer is the primary voltage. This voltage can be transformed or changed to 120 volts for household usage."

These sentences are wrong.

 

The voltage going into the transformer (from the electric company) is the "primary voltage" NOT the voltage "coming in from" transformer. Once the voltage reaches our homes it is not "transformed or changed" to 120 volts. That would require another transformer. What comes into our homes is 240 which can be wired for 120 volts.

 

A correct statement would be “The voltage on the secondary windings of the utility transformer is 120 volts from the neutral conductor to either hot conductor, and 240 volts between the two hot conductors.”

Page 219

"Amperage can be identified by the number on the fuse or circuit breaker located on the main panel board."

No. It's more complicated than that, as the author herself states on the same page at the "Putting it to Work" statement and at page 230. It is confusing for students to have this incorrect statement before them even if it's corrected  at the next paragraph and then again 11 pages later. Noting the amperage to a house is an important and sometimes complicated task for a home inspector. It is a poor practice to muddy the waters for them with this incorrect statement stated as fact.

Page 223

"Although electric power is measured in  watt-hours, it is reported in  kilowatt hours because the amount increases rapidly.

This doesn't make any sense and is an example of the poor writing in this book that misleads and confuses.

Page 223

"The service entrance cable is fastened to the building with cable clamps placed approximately four feet apart.

This is wrong. The clamps must be "at intervals not exceeding 750 mm (30 in.)" NEC 250.51(A) and within 12 inches of each box

Page 226

"According to the NEC, the main disconnect switches on the panel board may not have more than six switches or six circuit breakers mounted in a single enclosure."

An example of poor writing which makes for a confusing sentence.

 

What the author is trying to say is that there should be no more than 6 hand movements to shut down all power.

Page 226

"If the wire size or service is not strong enough for the electrical needs of the house, the circuits overheat, causing fuses to melt or circuit breakers to trip and therefore, interrupt the electrical service."

This is wrong.

The "wire size" not being "strong enough" is not why fuses blow or why circuit breakers trip. An overcurrent causes a "fuse to melt or a circuit breaker to trip" because the current on the circuit is greater than the fuse or circuit breaker's amperage rating.

 

The fuse or circuit breaker rating  for a particular wire size is determined by the ability of the wire to carry current at reasonably low (safe) temperatures.

 

Circuit breakers and fuses protect wires of all sizes from overcurrent.

Page 228

"Circuit breakers are more convenient and safer than fuses."

This is misleading and may make students believe that circuit breakers can protect a circuit better than a fuse can. That belief is not academically defensible. Indeed, there are some applications which specifically require a fuse because of a fuse's reliability. Fuses may be less "safe" because changing a fuse entails more risk than pushing a circuit breaker switch and because improper fuse sizes can be installed.

Page 230

"Figure 9.16 illustrates a main panel board with circuit breakers in good condition."

This is dangerously misleading. Figure 9.16 illustrates a panelboard with the cover on. No one can tell that the circuit breakers are in "good condition' by looking at a panelboard with the cover on, nor can they tell the condition of a circuit breaker by looking at it. You can sometimes see negatives but the absence of negatives is not a positive.

Page 230

"Make sure that the main panel board is grounded to a ground rod or main water pipe. If it is grounded to a metal water pipe, it must be bonded."

"Bonding" is the connection of one material to another. To say that the water pipe must be "bonded" is to say something incomplete. Something can only be "bonded" to something else. This sentence can only confuse a student.

Page 233

"Branch circuit wiring conducts all amperage ratings and goes to the switches and outlets within the house."

Another poor sentence that doesn't make any sense. "amperage ratings" are not conducted in wires. Electrical charges and electrical energy (among other things) are conducted in wires.

 

Fuses and circuit breakers have "amperage ratings" which make them trip when they sense an overcurrent, that is, a current over the "amperage ratings."

Page 233-234

"A qualified electrician can change the receptacles that are marked AL/CU with devices marked CO/ALR".

This is the author telling home inspection students how a home with single strand aluminum branch circuit wiring can be made safe.

 

Wiring a home with single strand aluminum branch circuit wiring is a complicated and much debated issue which requires a great deal of study by home inspectors and electric professionals alike. It is therefore improper for the author of this error-filled book to casually tell home inspection students what an electrician can do or cannot do to make a home with single strand aluminum branch circuit wiring safe in one thoughtless sentence.

Page 237

"Boxes must be large enough for all of the enclosed conductors and wiring devices. The only exception to this, according to code, allows multiple cables to be run through a single knockout opening in a non metallic box (Figure 9.19)."

An incomprehensible set of sentences. The second sentence has nothing to do with the first.

 

Try to imagine what this type of error or typo or poor writing can do to a student trying to learn how to inspect electrical systems.

Page 238

"Two-prong or slot outlets do not have a ground slot: three-prong plugs do."

Sloppy writing.

 

A "slot" is a hole in a receptacle. The "slot" accepts "plugs" from our appliances. So a "three-prong plug" does not have a "ground slot."

Page 238

"A ground fault circuit interrupter (GFCI) looks very much like a typical receptacle except that it has a test and reset button. This device shuts off a circuit immediately if it senses a short circuit."

This is wrong.

 

This device shuts off a circuit immediately if it senses a ground fault.

Page 240

"When there is a two-prong receptacle, the outlet is generally not grounded (unless the property owner has placed a two prong outlet over an outlet that was previously three-pronged). The client must be told that there is  no grounding system."

This is ridiculous.

 

A two-prong receptacle is not evidence that there is "no grounding system."

Page 244

Practice Test Question # 10:

Which of the following is TRUE?

  1. Most fuses have to be replaced when melted.
  2. Fuses with different amperage ratings can be placed in to the same socket on the panel board

Both A and C are correct, although the book says that "A" is the correct answer. With Edison based fuses, fuses with different amperage ratings can be placed in the same socket on the panelboard. They're not suppose to be but they can be.

Page 244

Practice Test Question #14:

The larger the diameter of a conductor:

A.

B. the more current it can carry.

The "correct" answer, "B" should say "the more current it can safely carry. " because a smaller diameter conductor can carry as much current as a larger diameter conductor but may not be able to do it safely.

Page 244

Practice Question # 16

Which is the following is TRUE regarding BX cable? It is:

A. in a metallic enclosure.

BX cable is not in a metallic enclosure. BX cable has a metallic covering.