Reader Response to “Making the Case for Measuring Voltage” (June 2018):
In the article “Making the Case for Measuring Voltage” (June 2018), Charles Buell pointed out that water heaters, clothes dryers and ovens will take 25% longer to heat up and perform their specific task if they are dual-rated 208VAC/240VAC. One thing that Mr. Buell did not point out is that the total amount of energy in each case is the same (kWH), even though the run-time is longer.
Another thing that he neglected to mention is that there are 208VAC-specific heating elements available to restore the heating capability of any normal tank water heater for around $50 for the pair of elements (3500, 4500 and 5500W units are all available). The recovery rate will be restored, or nearly restored, to the rating plate value.
He also stated that voltages measured at any other point will be a bit lower than expected if measured, say, at a dryer receptacle than on the main lugs. This is simply not true if there is no load on the circuit (i.e., the dryer is unplugged to measure the voltage [voltage drop, V = IR, and if I = 0, the voltage will be the same as the entry point if your measurement device is high impedance]).
Going further, regardless if the voltage is 110V-rated or 130V-rated, we should be recommending LED bulbs, which are typically rated for 100VAC-250VAC and consume around 80% to 85% less power per lumen than incandescent bulbs, for our clients to save power and money.
I know I may be nit-picking, but I, too, am a member of the ASHI Technical Review Committee and have been an electrical engineer for 36 years. If we are going to go the extra mile, let’s give our clients the best information we can (and yes, I do measure the voltage in several places in the house, including the main lugs).
-- Victor G. Faggella, ACI, Centurion Home Inspections, Inc., Woodbury, CT
To keep the article from getting too long, I could not include all the possible paths that this topic could take. Of course, the amount of energy consumed will be roughly the same—even while taking longer. Also, I did not discuss 208-specific elements for the same reason. It would not help all the other appliances involved and it could result in having to rewire as the wiring already installed might be too small. Certainly, I should not have said the voltage would drop over distance. It does under a load, but otherwise it will be accurate to measure anywhere in the system.
To add some further context to the article, although I cannot speak for ASHI, if anyone does not want to do this measuring, they certainly do not have to. I discuss in the article how an inspector can comment if they do not measure. In addition, per the ASHI Standard of Practice, we are required to remove the panel cover as long as we deem it safe to do so. Once it is off, it is nowhere near as dangerous to do measuring as it is to take the cover off in the first place. Both can be accomplished safely. Measuring can be done at any 208/240 receptacle and would be no more complicated than using a three-light tester that most inspectors routinely use.
-- Charles Buell, ACI, licensed home inspector in the state of Washington, and instructor, residential home inspection courses, Bellingham Technical College, Bellingham, WA
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