Figure 9
sure is felt at the nozzle port, the pressure switch will close and turn on the booster pump. Conversely, as soon as the burner shuts down the booster pump will also. As I said, a small pre-purge makes this type of system work flawlessly, but a post-purge (motor off-delay) doesn't really do much for the oil supply. I'll have more to say about purges and delays in another article and you may be surprised. You can also do this with a vacuum switch, also located on each burner pump, and Honeywell has a catalog full of them that they sell as Hobbs switches. There are other ways to control
Figure 10
the booster with relays and switches, but for my money this is the easiest way. So, this is a new article that will end up in
my "WIRING & Fuel Burning Equipment" series, what we think is the best wiring and controls resource for heating technicians ever and you can buy all five volumes in the "Book Store" on my website. By the way, did you notice how those
return lines terminate in Figure 9? If you pipe them that way you can't get gravity feed out of your pump return line and if you are getting that problem you probably don't need the return line anyway. So, stop ago-
Figure 11
nizing over those problem jobs before it gets cold again and put one of these next gen- eration booster pumps next to the oil tank. The accounts you save and make happy just might mean your job and remember, it's a lot easier to work smart than work hard and oil heat doesn't have to die!
See ya.
George Lanthier is the owner of Firedragon Academy, a teaching, publishing and consulting firm. He is the author of over 40 books and manuals on gas and oil heating and HVAC subjects. He is a CETP, NORA, NATE and PMEF Proctor and can be reached at 608 Moose Hill Road, Leicester, MA 01524. His phone is 508-421-3490 and his website can be found at www.FiredragonEnt.com
www.fueloilnews.com | FUEL OIL NEWS | SEPTEMBER 2012 23
