• Love, not pay, draws teachers • Understanding the utility Love, not pay, draws teachers I am not a teacher, nor am I related to one. Hawai‘i public schools are a miserable mess, ranking 43rd among the 50 states. Attitudes
• Love, not pay, draws teachers
• Understanding the utility
Love, not pay, draws teachers
I am not a teacher, nor am I related to one. Hawai‘i public schools are a miserable mess, ranking 43rd among the 50 states. Attitudes like Howard Tolbe’s are among the main reasons. (“Teachers, not schools, should pay for drug testing,” Letters, Dec. 28)
He writes, “… teachers are already in a very high paying profession.” Are you kidding? For the years of education required, teaching is the lowest-paid of the professions. Truck drivers are better paid. Most teachers struggle to make ends meet. It is only love that keeps our dedicated teachers showing up every day.
To expect teachers to pay for their own drug testing adds injury to insult. Tolbe’s insinuation that our teachers are drug users and pushers is outrageous. It is the students who need to be tested for drugs!
Our schools will improve only when teachers are empowered to take control of their classrooms. They need the authority to kick the unruly and disruptive out of the room. Only then will classrooms become places where learning can actually happen.
• Jeff Knope, Kapa‘a
thegardenisland.com
Editor’s Note: This is the first of a two-part letter discussing electric utility. The second part will appear tomorrow.
Understanding the utility
I would like to expand upon the readers’ comments expressed in letters from Ken DaVico (“KIUC a disaster,” Letters, Dec. 27) and Bobby Ritch (“KIUC’s fluctuations,” Letters, Dec. 28. I apologize in advance for the length of this discussion but, the subject cannot be dealt with properly by using a few, simple, generalizations.
While both letters mention some of the problems we all experience due to being KIUC’s customers, they have, in my opinion, some correct and some incorrect statements within them.
I have spent more than 50 years in the electrical industry as an electrician performing construction, maintenance and design of virtually every type of electrical and electronic systems for residential, commercial, industrial, military and government facilities.
The two letters referred to above mention voltage drop and, by suggestion, infer that there is too much variation in voltage at their home. The truth is that there will always be voltage drops and variations with any utility company. There is no such thing as a constant voltage supply for any utility customer.
The reason a constant voltage is not possible is that every wire in the utility’s and the customers’ electrical circuits have resistance. The longer the wires are, the more resistance in the circuit. Voltage drop is the product of the line’s resistance and the current flowing in the line.
In a neighborhood, the current flowing in the utility’s wires are always changing due to customer loads turning on and off at random. As an example, if one customer lives next door to a utility’s generator site and their electrical service always provides exactly 120 volts (perfect regulation by the utility) but you are connected to this same circuit and live several blocks away, along with other customers, your service may show noticeable variations.
There is only one national standard for utilization voltage regulation and this is the American National System Institute document C84.1 which suggests that the utility provide a 120 volt “nominal” standard voltage to be within +/- 5 percent (114 to 126 volts) for distribution service (the connection point where your house or business connects to the utility’s wiring).
This standard then acknowledges that customer utilization (the wiring between the utility’s connection point and the farthest load within your house or business) allow for a total voltage range of +6/-13 percent (104.4 to 127.2 volts). This means that any equipment you plug into your wiring should be able to survive voltage fluctuations from about 104 volts up to 127 volts. Some equipment manuals do not specify their voltage tolerance range; and, may only state that the voltage be 120 volts. This implication is suggesting the “nominal” voltage input only.
The National Electrical Code, which governs the size of wiring in your house or business, states that your wiring system must be designed to allow no more than a 5% voltage drop from the utility connection to the farthest load in your house/ business. The implication here is that you may measure different voltages at different locations within your house or business and still be “within the code”. The NEC defers to ANSI C84.1, mentioned above, for definitions and descriptions of various voltages.
Further complicating the voltage discussion is the fact the motors are treated separately by the National Electrical Manufacturers Association which recommends that all electrical appliances and motors should operate at their nameplate rating +/-10 percent. Interestingly, motor “nameplate” nominal ratings are 115 volts which means they should operate correctly from 103.5 to 126.5 volts. In other words, 103.5 volts may be OK for your refrigerator, but not for your TV which is on the same circuit and needs 104.4 volts minimum to operate reliably.
Utility companies try to regulate their sources starting at their generating sites and larger substations as the power is distributed to their customers.
In times of light load, the generated voltage could be high, so the utilities reduce their generator outputs (if the entire system is lightly loaded); and may individually and automatically adjust substation transformer ratios in local neighborhoods to try to provide a reasonably constant voltage at the far end of their longest lines.
Conversely, if the load becomes greater causing the voltage to drop excessively, neighborhood transformers will increase their outputs; and, if the total system load becomes heavy, the generator outputs will be increased.
There is “good news” and “bad news” about the utility’s regulation systems. If the electrical service of your house or business is close to a regulation device, your voltage will be more constant. The farther away you are, the more voltage drops from the longer wires and more customers connected between you and the regulator, the more extreme the voltage variations. Being close to a regulator is not always ideal either since the transients generated when the regulator switches values may be more severe and thus could be more damaging.
• Elton Davis, Kapa‘a
