HELP Speed Control on VF3000 Draft Fan
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- New Member
- Posts: 12
- Joined: Mon. Mar. 31, 2008 4:45 pm
- Location: Venango Pa 16440
- Stoker Coal Boiler: Harman VF-3000
- Coal Size/Type: Rice
I just hooked up a paddle fan speed controler on my vf3000 like Highlander explained to do on a previous post.. It is powered by both sockets on the stoker controler ,the combustion blower socket powers it directly,and the distribution blower socket powers it through the speed control. Its supose to run full speed during the stoke, and then revert back to slower speed with power from the distribution socket when not stokeing.But when I hooked up mine it still stokes when running thru the speed controler.Its backfeeding power back into stoker controler. Did I hook something up wrong has any one tried this set up.
- Highlander
- Member
- Posts: 217
- Joined: Tue. Dec. 05, 2006 9:48 pm
- Location: Highland Lakes NJ
- Stoker Coal Boiler: Harman VF3000 Sold
- Hand Fed Coal Stove: Vermont Castings Resolute
- Coal Size/Type: Nut
Yes, there was a problem with the way I described the original hookup, Coalmeister tried it and found the same problem. Here is the response that I PM'd him:
You probably wired it as described, I had opened up a Harman control box a while back and thought I saw 3 relays, one for each socket, I may have been mistaken, or they may have changed the design, don't know, doesn't really matter.
From what you are describing, you are seeing a backfeed of power from the fan control to the stoker motor, if the two recepticals share a common relay, then this would happen.
There are two ways to fix this, the simplest is to plug the combustion blower plug, the direct connect one, into the distribution blower socket and set the extend time to something small say a minute or so. The other plug, the one going to the speed control would then get plugged into the SAME receptical as the Harman stoker control box is plugged into. It is important that you plug it into the same receptical on the wall so that there is no possibility of being on two different legs of your 240V service which is possible. Turn the speed control off, when plugging the circuit in, since there is a posibility of having 120V on the pins of the other plug.
The alternative method is to use a relay with a 120V coil plugged into the combustion blower socket, and then use the contacts of the relay to bypass the fan control when the unit is stoking.
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- New Member
- Posts: 12
- Joined: Mon. Mar. 31, 2008 4:45 pm
- Location: Venango Pa 16440
- Stoker Coal Boiler: Harman VF-3000
- Coal Size/Type: Rice
Highlander thanks for the quick reply .That's what I was thinking. I'll try it one of the other ways ,hope to get it to work .I would like to see if it will help cut down on my unburnt coal in my ash. Love the vf3000 so far, been running a month now.This coal forum is great!