The home heating oil industry has a long and proud history, and Fuel Oil News has been there supporting it since 1935. It is an industry that has faced many challenges during that time. In its 77th year, Fuel Oil News is doing more than just holding
Issue link: https://read.dmtmag.com/i/739848
42 NOVEMBER 2016 | FUEL OIL NEWS | www.fueloilnews.com times per year. With these criteria established let's look at what would happen. That's right! The stack switch only runs the ignition system for 3.8% of the time that the infamous three wire cad cell control does. The first cad-cell control looked at is half of that, that's an improvement, not the intermittent one! But take a closer look at that one-second unit; it only operates the transformer 0.0005% of the time. Or, put another way, that transformer which previously had a life expectancy of just one year now has a life expectancy of 2,000 years. Remember that burner company I mentioned work- ing for? Well, their burners are the ones that have ignition on for only one second during normal light-off so they have a good reputation for not only lighting-off smoothly, but also for very few ignition problems. But as shown they just know "the secret". As you can see, by changing the control type, you probably won't have to change as many transformers or ignitors any more. You also will lower the number of service calls for electrode adjustments between tune ups and will probably have a happy customer who has no reason to switch to another fuel. Two more things that you may also want to consider: 1. Most commercial/industrial burners are run on inter- rupted ignition, which generally, after proving flame on low or pilot fire, shut off in less than one second. 2. No burner manufacturer that we spoke to has ever recom- mended constant ignition on flame retention designs except for just a couple of unusual problems. As always the manufacturer should be consulted first, should you feel that you have an unusual job. So the original question here was: Did they build transformers better in the old days? I don't know, but who really does? I guess the servicemen who do know are the ones who run their burners with interrupted and not intermittent (constant) ignition. This column is an update on the fifth article that I ever wrote back in January of 1992. In the 24 years that have passed a few things have changed. The PMEF book became the PMAA book and then came out as an entirely new publication as the NORA OTM. In 1992 there was only one primary control manufac- turer making controls available that would provide interrupted ignition. Now there are three. Stack switches were made illegal in Massachusetts on new installations in 1995 and in 2014 Massachusetts made 15-second, interrupted ignition the only thing allowed. Everything changes. See ya! l F O N GEORGE LANTHIER is the owner of Firedragon Academy, a 25-year-old Massachusetts Certified School teaching both gas and oil and other heating subjects. Firedragon Academy has its train- ing facility in Sturbridge, Mass., at the Beckett Training Center. Firedragon is also a publishing firm publishing George's over 60 books and manuals on HVAC subjects. He is a CETP, NATE, NORA, PMAA and PMEF proctor and has been a Massachusetts Certified Instructor since 1975. He can be reached at 608 Moose Hill Road, Leicester, MA 01524. His phone is 508-421-3490 and his website is FiredragonEnt.com. EXAMPLE 1: Intermittent ignition: Ignition is on when the burner runs 800 gallons at 0.85 gph = 941 hours of "ignition-on" time with intermittent (constant) ignition using a three-wire relay, Figure 3. Consider that 941 hours per year. Think that will burn the tips off electrodes, kill the ignitor/trans- former and lead to all kinds of trouble? You're damned right! By the way, the most popular three-wire relay is also the most expensive one to buy and for your cus- tomer to operate! EXAMPLE 2: Interrupted ignition: timed or sequenced ignition A. Stack type relays (typical) 2800 starts x 60 seconds = 46.6 hours' "ignition-on" time. B. Cad cell type relays 2800 starts x 26 seconds = 20.2 hours; based on 15-second pre-purge, one-second TFI and 10-second ignition carry-over time. 2800 starts x 1 second = 46 minutes of ignition on time, that's minutes, not hours.