[LarryS]

coming from a slight different angle, yes in a restricted airflow situation the load in most situations would reduce and the speed would increase (its in effect trying to work in a partial vacuum) but would that then lead (long term) to a rise in operating temp's and therefore increase the load and resistance - as like most motors it ultimately relies on air to cool itself, just a thought.

 

[leftlanetruckin]

Larry, so it would make sense that the motors would heat up the relays and thus screw the fuse box up? More draw = more heat right? Especially in the confined spaces of anywhere one a P38 :lol:

Martin

 

[LarryS]

Could be Martin (and i stress could be) there are so many variables, like how close is the restriction to the back of the fan - in that case how much air is able to get behind the fan from the front, does it become in effect completely sealed ...etc....etc...etc.

 

[leftlanetruckin]

A mystery for sure.
Scotty said he was going to inspect the duct work that he has on his bench to see the air flow to the blower fans etc. If it looks like it is all pretty well sealed up and relies heavily on the filtered air, then I could see the pollen filters being an issue in increased amperage draw to the blower motors, then fuse box issues etc. :think:
If there is air able to get to the motors regardless, then the problem could be elsewhere I guess...

Martin

 

[LarryS]

That said this flies away from the main site 'fusebox repairs' theory which acknowledges and also dismisses the pollen theory for the reduced load argument, corrosive battery vapour and spilt coolant. But to my mind if it can't keep itself cool then long term i think the load and resistance would increase regardless of the initial reduction due to the restriction.

 

[p38arover]

That said this flies away from the main site 'fusebox repairs' theory which acknowledges and also dismisses the pollen theory for the reduced load argument, corrosive battery vapour and spilt coolant.

Don't forget, I wrote that page...... :lol:

 

[LarryS]

:lol: exactly, just keeping a balanced view - as their all valid.

 

[leftlanetruckin]

Hoping to get a load to the NW when you make it over here next time Ron :thumb:
Told Carl to keep me posted as to dates and locations etc mate.

Martin

 

[Guest]

That said this flies away from the main site 'fusebox repairs' theory which acknowledges and also dismisses the pollen theory for the reduced load argument, corrosive battery vapour and spilt coolant.

Don't forget, I wrote that page...... :lol:

an awesome write up BTW... it was a great help to me =)

 

[p38arover]

Hoping to get a load to the NW when you make it over here next time Ron :thumb:
Told Carl to keep me posted as to dates and locations etc mate.

Martin

I'd love to catch up. I'll be in SFO for the last 9 days of my trip.

 

[p38arover]

That said this flies away from the main site 'fusebox repairs' theory which acknowledges and also dismisses the pollen theory for the reduced load argument, corrosive battery vapour and spilt coolant.

Don't forget, I wrote that page...... :lol:

an awesome write up BTW... it was a great help to me =)

Thanks very much. I appreciate the feedback. I need to update a few pages on the main site.

 

[leftlanetruckin]

Hoping to get a load to the NW when you make it over here next time Ron :thumb:
Told Carl to keep me posted as to dates and locations etc mate.

Martin

I'd love to catch up. I'll be in SFO for the last 9 days of my trip.

Tell Carl to keep me posted when he knows the dates and I will see if I can get a run out to the north west then mate. I go to Seattle on a semi regular basis, so that shouldn't be too much of a problem :thumb:

Martin

 

[Scotty]

Test completed: The results are very interesting to say the least! :think:

Shows the layout:

Shows the recirculation door closed:

Shows the amp draw with out the pollen filter in place, recirculation door is still closed:

Shows the amp draw with pollen filter in place, recirculation door still closed

Shows a representation of a clogged pollen filter, recirculation door is still closed:

Note: In all three test the duct work from the pollen filter housing to the heater
matrix, has been sealed with foam tape.

I guess were never to old to learn..

 

[leftlanetruckin]

Doesnt make a lick of sense to me neither Scotty, but as you said, never too old etc :lol:
I stand fully corrected

Martin

 

[Scotty]

Yeah what you said Martin, :lol: thanks for your help with the experiment today..

 

[leftlanetruckin]

No problem mate.

Martin

 

[Guest]

You confirmed with your test what was said in this tread before

That is true if you increase the load on the motor. However, if the airflow is reduced by blocked filters, the motors actually have a reduced load so they draw less current.

 

[leftlanetruckin]

You confirmed with your test what was said in this tread before

And admitted being incorrect :thumb:
Nothing like a physical test to confirm/rule out a theory is there?
Not to mention the fact that Scotty is about the only person to have a complete HVAC system ready to lay out on his driveway, AND take the time and trouble to do an accurate test :thumb:

Martin

 

[p38arover]

Thanks Scotty, that's really good. Would you mind if I add that to the main site?

(I was worried that my memory from when I did my electronics training 45 years ago might have been hazy! )

I seem to recall that this may not be the case with axial fans but is with squirrel cage fans.

 

[leftlanetruckin]

Axial and squirrel fans Ron???
Educamate me....

martin