Letters To The Editor -- August 2004
Controls Are Nothing New
I just read Carol Fey's column "Parallel Vs. Series Circuits" (April 2004). I happen to be a master electrician and a journeyman instrument man. I also run my own electrical contracting firm.I'd like to say I take offense to this column. It was well written until you get to the last couple of paragraphs - in which it states that a control tech is much more capable at troubleshooting a control system.
Most electricians spend four or five years in an apprenticeship learning about controls, loads, series and parallel circuits. That's how we determine wire sizes, current draw, etc. How does a control tech get his training? Most of the ones we have to help out get it on the job.
Perhaps it is my instrument background or my nature of business, but controls are nothing new to the electrical industry. I have been installing Honeywell Controls for 30 years now and have instructed more control techs than vice versa.
David Moser
Moser Electric
Wisconsin Rapids, Wis.
Carol Fey responds: You are the exception to what we often see in the field - and we appreciate the heck out of you! (My dad and granddad were both electricians. I'm a former IBEW member. So don't think I'm anti-electrician!)
Here's what I did a couple years ago. Because so many controls were being burned by electricians (and I'm talking about the ordinary pulling-wires-from-here-to-there-with-no-brain-engaged type of guy), I hired an electrician to just talk. The idea was that I could ask any question, and he would answer it the best he could.
Q: How do electricians learn to wire controls? A: We don't, and we don't want to. It's sissy stuff - low voltage can't hurt you.
Q: How do you think when you're wiring a circuit. A: We don't think in circuits. We pull wires from one place and put them another place.
Q: Why do you accept work wiring controls? A: The plumbers (hydronic heating guys) beg us, so we feel sorry for them and say OK.
In teaching and writing, I'm trying to get heating guys (often plumbers) to see they need to take responsibility for their whole job and learn how to do it. I realize you have a lot of special knowledge. But wiring up the controls for a boiler just ain't that hard. First he needs to get over being scared or thinking he's too dumb to do it himself.
Where can they learn? From the boiler manufacturer reps, from the distributor techie guy, from guys in the field who know, from books and classes.
Siggy's Right On
John Siegenthaler has nailed the lid on the suspended tube coffin! I felt like he was writing about a radiant retrofit we're just in the process of completing. Identical 55 degrees F indoor temperatures on a design day and very upset homeowners.The builder furnished me with pictures taken during the installation, which revealed it was a suspended tube application with little to no insulation between the tubing and the ceiling below. Needless to say, the first floor had both a radiant floor and a radiant ceiling due to the extensive back-loss from above. Warm and toasty downstairs. Frigid upstairs. Adding to the problem were an ineffective control strategy, restricted flow used as a means of creating wide delta-Ts and several carpeted areas further restricting heat transfer to the upper floor.
By using a detailed radiant heat loss program, it was determined that water delivery temperatures exceeding 260 degrees F were required to adequately heat several rooms! It was necessary to abandon the suspended tubing application in place and start over with radiant wall and floor panels. A new control strategy along with more advanced piping methods replaced most of what had been cluttering up the basement. Water delivery temperatures are much lower (by as much as 80 degrees F in some zones).
A couple of things led to the demise of the original two-year-old radiant installation: 1) the installer did not perform his own heat loss or design and, therefore, did not understand the importance of insulation, how much was required to drive the heat upwards or the impact carpet and padding would have on system performance; and 2) there was a lack of communication between the builder, owners, other trades and the mechanical contractor.
Education and communication are the keys that will unlock the doors barring the way to systems that can exceed customer expectations. John Siegenthaler's columns and design software shine like a beacon in a long, cold winter's night.
Dave Yates
F.W. Behler
York, Pa.
