adjusting the air on a power flame gas burner

zepfan

does anyone know how to adjust the air intake on a powerflame model# fdm 225 gas burner? i have attached some pictures of the burner in question,and have contacted the manufacturer and they were of little help,they just kept saying yes to everything.it was as if they were unsure.it has a damper on the intake side that is attached to the mod.motor it opens as the motor, which is linked to the gas valve turns.the problem is unless the burner is in high fire,which is rare,the buner produces too much co.the manufacturer says to undo the setscrew on the mod. motor and open it that way,that does not seem right to me,but i am unsure as well. thanks to all

RJ_4

powerflame

Look on Yahoo, there is a pdf for the IOM for that burner. You should have a solid background in power burners and have the right tools (draft guage,combustion anyl.and gas press. manometer ) before working on this burner, there is detailed info on setting up and start up.

zepfan

thanks

thanks for the help,however the pdf that is online is the same one that is shipped with the burner.it does not explain how to adjust the air.i have all the combustion test equpment necessary to work on this burner as i have before.i was just wondering if anyone had experience with powerflame,that's all.

RJ_4

burner

I would sub out a burner co to help, I had to do that once, and learned invaluable info on setting up power burners , I just explained to my boss that factory help was needed for start up. Remember the burner goes into high fire damper pos. for prepurge than goes to low fire pos. for pilot ign. high CO can be caused by to little air and to much air

Charlie from wmass

If you take a deep breath

grab a cup of coffee and grab a seat under a good light it is all in that manual. Read it step by step and do it by the numbers. I was sent to work on a power burner a decade, maybe two decades ago, with no back ground on these burners. In half an hour I had it lighting smooth and in an hour is was shifting from high to low and back without spiking the CO levels.

furnacefigher15

Adjust everything

You have to adjust both the linkages, and the air shutter.

The position of the linkange on the crank arm at the firing rate motor effects the rate at which the air shutter opens in relation to the butterfly valve on the gas train. And the linkage adjustment sets the starting point for the damper.

Here is my process, regardless of make or manufacture, as they all essentially work the same. (By the way, I do this day in, day out roughly 6 months a year.)

Before starting the burner, lubricate the air shutter, and be sure it will not bind.



Step one:  Run the unit in high fire, and set the max firing rate to that listed on the appliance. This is done by clocking the gas meter for a minute, counting rotations in that time, then doing the math for one hour. 1050 btu per cubic foot is a general guideline, but the heat content will vary based on the fuel in your area. Manifold gas pressure is virtually irrelevent in a power burner, regardless of what that manual says. On large boilers, it is essential to aquire the actual heat content of a cubic foot of gas from the gas supplier.

Step 2 : Put the burner in manual firing rate mode and divide the potentiometer into 10 or so segments.

Step 3 : Mark all linkange and drive arm positions for reference, then drive the motor to minimum position, and tweak the air settings until clean smooth reliable ignition and quality stack readings are met.

Step 4 : drive firing rate motor to the next segment and see what the results in the stack are, tweak position on the crank arm until clean combustion is achieved, then go back to minimum and see if its still good, repeat process all the way to high fire.

The general idea is to get the O2 readings as low as possible w/o producing excessive CO.

A reasonable target would be 4% O2 10% CO2, and below 50 ppm CO ( air free)

This process can take anywhere from an hour to all day. Some burners are more finicky then others. Do not rush this process, come back on a second day if need be. I've had some burners take me a week to tune in just right.

tim smith

Re: adjustment of Powerflame

Best suggestion is to find a local well seasoned commercial burner guy to set it up and you be there to learn. Will be invaluable if you find a good teacher/tech.  Good luck, Tim