Difficulty to stat blower fan in lennox oil furnace

[naelec]

Good morning and Happy new year to everybody....
My problem is the following : i have a Lennox elite serie 2003 oil furnace (a big one 140000btu,I think) which is causing me headaches:
After 1 and half year use ,the relays under the control board started to desolder in the blower fan circuit .The fan was set at high speed because the house is big...
After resoldering them correctly the blower works fine till now.....
Same thing,relays need to be resolder but also the wires which plugs for the blower fan get burned....
After fixing them,i get the following result : difficulty to start the blower (take like 6 or 7 seconds to reach its speed). During this time,high starting current of course !! After it starts,current is 6,4A. I check the capacitor it seems alright and test around 6 microfarads.
Also mechanically all is free and the filters are clean !
Is this value OK. For now i set the fan continuously ON operation and medium speed....
I am very anxious about this because we have very cold weather at this time.
Unhappily i cannot find a model or serial number. The motor fan is direct drive but also i cannot read the nameplate.
Assistance would be greatly appreciate.Thanks in advance

[pacnw]

need to post exact model and serial number for any specific information.

this is not a DIY forum, so info may be minimal.

my experience with a similar situation was due to an overload on the furnace circuit, it was not dedicated causing the burnt wire scenario and fixed when those loads removed.

also, without specifics, capacitor sounds weak.

those boards, BCC-3, are known to have the relays fail. usually there is a big black mark on metal behind the board. replacing board is recommended, as weak/bad relays may be a part of the issue.

[t527ed]

cap reading is very low for that furnace if its what i think it is.
furnace should have sticker with model #. probably starts with O23, find it and post it.

[naelec]

First of all PACNW a very huge thanks to reply so fast
Unfortunately ,i cannot find a serial number or model number...I just see on a front panel ,a yellow efficiency sticker showing 81 efficiency !!!
But you are perfectly right,,i got this black mark on the metal under the PCB.
There are a choice of 4 speed connexions on the motor fan itself... Would you tell me roughly what should be the capacitor value .
Have a great day and many thanks again

need to post exact model and serial number for any specific information.

this is not a DIY forum, so info may be minimal.

my experience with a similar situation was due to an overload on the furnace circuit, it was not dedicated causing the burnt wire scenario and fixed when those loads removed.

also, without specifics, capacitor sounds weak.

those boards, BCC-3, are known to have the relays fail. usually there is a big black mark on metal behind the board. replacing board is recommended, as weak/bad relays may be a part of the issue.

[naelec]

Many thanks t527ed.
I cannot find any model and serial number!!!!!!!! Where should they be written
How many microfarads ,roughly, is necessary.....
Have a great day

cap reading is very low for that furnace if its what i think it is.
furnace should have sticker with model #. probably starts with O23, find it and post it.

[t527ed]

Too much DIY

[beenthere]

Sorry, this is not a DIY site.

[t527ed]

Too much DIY

really?????

[naelec]

Sorry everyone,I finally found the model and serail (hidden back in insulation). Model OF23Q5-140/154R-5A
serial 8402G15480

[naelec]

In fact , i think i posted in the wrong section...I am an electronic contractor, Naessens electronic inc, mainly in industrial , but i also repaired electronic printed circuit board from all nature. So this BCC Lennox board that i repaired few times in the past,come from a customer ! Now i have to fix it under warranty, this is why I am asking information ,like the value of the blower capacitor and the exact type of the fan motor.... because i have no contact at Lennox.
So if somebody could answer me ,or give me name,or lennox parts supply ,or some sort of information ,it would be very helpfull.
Thanks in advance.

[pacnw]

you could try calling Lennox, or a local Lennox dealer for that information.

the motor would list the proper capacitor.

now is this your board in your furnace or in a customer's furnace, getting a little cloudy here now.