Blower On Delay

My Carrier 58MCA furnace has a 66sec Blower On delay. The problem is that I have to have the fan running constantly to assist the HRV Ventilator feeding the return duct. When the Blower Fan stops for "warm up", the ventilator is blowing out the unfiltered return ducts, sending dust and crap into the air.
Can I switch off the Blower On Delay? What if the blower is running off of a FanHandler (so it's quite slow during normal Fan On)? Would disabling the Delay impede the warm-up of the heat exchanger enough to cause a severe performance problem?
How can the Blower On Delay be modified? After studying the wiring diagrams, it seems that the feature is not field adjustable.
Peace, Dan
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What's the fucking problem? You say that you're running the fan continous.

War, AHM
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Yes--but when the call comes for heat, the furnace automatically stops the fan for 66sec while the burners light and the heat exchanger warms up--then the fan comes back on. During this 66sec, my ventilator, whose supply is connected to the furnace return, blows out the return vents (since the furnace has temp. stopped pulling the return air). Get it? Now, how do I disable this damn automatic "pause" in the continuous fan??
Peace, Dan
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wrote:

Put in for a position with Carrier as a Design Engineer and re-design the board to your own specs. Im sure if you'd like, Todd H would be more than happy to help you with those design changes. Bubba
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Way to go Bubba, with a double hedda 2 boids with one stone.
Bob

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You can't. So now what? Think about it. What tells your air-to-air x-changer to turn on? Maybe that's what needs to be controlled? But how?
-zero
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Its easy.... just need to know where to look and what to look for.
(hint.... think Honeywell controls)
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The HRV ventilator runs constantly and is not electrically connected to the furnace or thermostat in any way. I just set it to run "normal" (50cfm) or "Boost" (100cfm) or "recirculation".
No Carrier experts here? In the manual they mentioned a 5sec delay for heat pumps (compared to the 66sec for NG)... what is the difference between the two boards? Maybe I can reproduce that same difference....?
I have to say that Carrier themselves are perhaps the most unhelpful company around... when I found a number (took quite some time), the only respose I got was "call your local installer"... well, too bad that guy doesn't have a clue either.. he doesn't make them; he just installs them... duh..
Peace, Dan
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Told you before.... 1) Call a *competent* tech 2) If you just have to DIY, then talk to some controls folks (Honeywell) 3) You have to be smarter than the piece of equipment you are working with.
After you have re-designed your furnace, don't forget to have it re-certified by UL, GAMA, and have it inspected by your local code enforcement authority, then make sure that your insurance is paid current.
I don't care what kind of degree you have... or what kind of experience you have... but fosile fuel burning appliances are not something that you really need to be playing with *UNLESS* you have the training, education, certifiications, licenses, and experience to do so.
That being said, its an easy fix, and no its not going to be free.
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It's not my intention to play with any part of the appliance that directly relates to the gas or some saftey features etc. But you don't need a lisence to do some simple wiring to the motor (ie. Fanhandler) or make a simple, mechanical adjustment to the board... if there is one possible...

Not free as in "I won't tell you for free" or as in "you have to buy an expensive part"? If it's #1, can I offer you some cash???? If it's #2, then I'm going to look into James' advice above... thanks...
Peace, Dan
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Noon-Air wrote:

Great. Can you direct me to the book with the "Competent Tech" listings in my area? I'm having trouble finding that directory...
Peace, Dan
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Change your filter.
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ya can't get there from here.
Troy

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It's a timer circuit on the board and it's not adjustable. You could alter it but it would be a pain. You won't find a schematic for it either. I'd probably try to use the low voltage side of the fan relay to control a relay at the ventilator so that it get's turned off when the furnace blower is off.

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James wrote:

James, you sound like a superhero... willing to help the weak... do you think shutting the ventilator each time would wear it out faster? When you power it down, some flaps inside close and of course, the motor doesn't sound like it likes to power up much when it does so(obviously designed to run continuous). Any experience with these Venmar HRV 2500 units?
Peace, Dan

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