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-   -   FBH - How to install, test and service (https://www.the75andztclub.co.uk/forum/showthread.php?t=100297)

HarryM1BYT 18th December 2011 17:55

Quote:

Originally Posted by Jakg (Post 878145)
Exhaust (flue?) is hot (or at least it was even before it was working properly!)

Then it must be working :xmas-smiley-004:

There will be some heat in the flue, drawn from the coolant, but that would make it warm.

Hot, as in far to hot to touch, means the FBH is burning.

HarryM1BYT 18th December 2011 18:17

Quote:

Originally Posted by Dragrad (Post 877769)
As requested the How to is here. If you amend or add to your OP please let me know and I will update the How To accordingly. :icon_smile:

An excellent piece of work Harry :xmas-smiley-025:

Thanks Dragrad....

Jakg 20th December 2011 12:31

Quote:

Originally Posted by HarryM1BYT (Post 878157)
Then it must be working :xmas-smiley-004:

There will be some heat in the flue, drawn from the coolant, but that would make it warm.

Hot, as in far to hot to touch, means the FBH is burning.

Went for a ~2 mile drive today... parked up.

Coolant pipe - cold to the touch.
FBH - OWWWWWWWWWWWWWWWWWW hot.

I think it's working :D

HarryM1BYT 20th December 2011 12:59

Quote:

Originally Posted by Jakg (Post 879677)
Went for a ~2 mile drive today... parked up.

Coolant pipe - cold to the touch.
FBH - OWWWWWWWWWWWWWWWWWW hot.

I think it's working :D

Excellent :xmas-smiley-003:

FredSpencer 27th December 2011 09:31

Images
 
For Harry:

Show the overall image at a size acceptable for the forum (usually 800px wide so downloading doesn't take too long).

As you can see I have boxed off an area to draw attention to it. This is the area where items 1, 2 and 3 are located.

Describe this image something like, "Items 1, 2 and 3 are located within the red box marked on this image and a second image shows this area in close up and with the values for each item."

http://www.lakelandphotography.net/./Fred/PCB2-800s.jpg

http://www.lakelandphotography.net/....B2_100pccr.jpg

HTH

HarryM1BYT 27th December 2011 11:44

Quote:

Originally Posted by FredSpencer (Post 884222)
For Harry:

Show the overall image at a size acceptable for the forum (usually 800px wide so downloading doesn't take too long).HTH

Thanks Fred, all sorted not I think, via a Photbucket account.

I'll see if I can add some photos for the FBH servicing, whilst I can still remember how to add them :snowfight1:

ose1665 8th January 2012 19:49

PCB test
 
Quote from almost the last line of your great 'How to'

'The above might be useful to know, so you can plonk a meter straight onto the FET driver output pins, to see if the glowpin and pumps are being fired etc.. '

Could this be clarified a little more please? what does FET mean? and where are the output pins, I know this might be small beer to people who deal with electronics but even if I knew where the output pins are you still need to place the other meter probe somewhere.:confused:

just my thoughts I think this is a masterful piece of work as is.:D

HarryM1BYT 8th January 2012 20:19

Quote:

Originally Posted by ose1665 (Post 893442)
Quote from almost the last line of your great 'How to'

'The above might be useful to know, so you can plonk a meter straight onto the FET driver output pins, to see if the glowpin and pumps are being fired etc.. '

Could this be clarified a little more please? what does FET mean? and where are the output pins, I know this might be small beer to people who deal with electronics but even if I knew where the output pins are you still need to place the other meter probe somewhere.:confused:

just my thoughts I think this is a masterful piece of work as is.:D

FET = Field Effect Transistor, the larger three pinned devices - which you do not really need to know.

There are 4x FET's we are interested in - glowpin, Fuel pump, air and water pump.

If you look at the photo you will see these components marked up with their function in green text. You should also be able to see a green 'o' next to one of the three pins. There is an 'o' adjacent to the output pin of the three pins. If you put a volt meter between ground and each of those marked pins in trun, you can determine from the voltage measured what the FBH is doing. It simply makes it much easier to check what is happening, rather than trying to stick a probe through the insulation.

Does that help?

ose1665 8th January 2012 20:36

Test power and polaraity glowpin FBH
 
OK I have another question on this bit...
Quote
'That gets you access to remove the burner unit and see inside the heat exchanger. Follow the two thick wires (mentioned earlier), to the glowpin, unclip the wires, unclip the glowpin - held by a spring P clip and very carefully remove it from the burner chamber. Test it by connecting its two terminals across 12v, where upon its square section end should in a few seconds become close to white hot. It is not designed to run continuously on 12v, so limit this test to a few seconds - just long enough to satisfy yourself that it glows. If it doesn't glow, then it has failed and no one has yet been able find a source for a replacement, but they are very expensive - maybe £60, even if you can manage to source one. Webasto only seem to sell them complete with the combustion chamber.'

If I understood correctly the glowpin uses quite a few amps so do you need to use a car battery to do the above test or would a battery charger 3-4amp capacity do the job?
Is the polarity of the test connection important? I would guess not but best to ask, as they are expensive and hard to get a replacement.

comments/advise would be appreciated, thanks:frightened:

ose1665 8th January 2012 20:43

Thanks
 
Quote:

Originally Posted by HarryM1BYT (Post 893467)
FET = Field Effect Transistor, the larger three pinned devices - which you do not really need to know.

There are 4x FET's we are interested in - glowpin, Fuel pump, air and water pump.

If you look at the photo you will see these components marked up with their function in green text. You should also be able to see a green 'o' next to one of the three pins. There is an 'o' adjacent to the output pin of the three pins. If you put a volt meter between ground and each of those marked pins in trun, you can determine from the voltage measured what the FBH is doing. It simply makes it much easier to check what is happening, rather than trying to stick a probe through the insulation.

Does that help?

That's great thanks :D understand it now :) think I missed some points you had listed TBH, so much to take in, will try and read more times in future:bowdown:


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