Harman P68 - 4 RPM or 6 RPM Feed Motor - Which is better?

[Don2222]

Hello

I have worked on older 4s and newer 6s installed in P68s but what is the difference? Does the 6 RPM put out more heat?

Four of the Dip switches on the Circuit Board sets the feed motor for the correct charge of pellets to the burn pot at startup and other differences but is there any real advantage to either setup?

What is your experience if you tried both setups?

See pics

 

[Don2222]

Hello

The auger is different for the old 4 RPM feeder motor than the auger for the new 6 RPM feeder motor - see different part #s below.
So why does the shorter auger have a faster motor ? ? ?
It is only 1 inch shorter, just does not make sense?

Are the fins on the 6 RPM stove father apart than the 4 RPM stove?

Looks like the
Newer 6 RPM motor part #3-20-60906 is for:
Harman P68 (After serial # 008280309)

Harman Auger part # 3-50-00565 This part measures roughly 9 1/2" from end to end.
P68 (After serial # 008280309)
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Older 4 RPM Part # 3-20-40904 motor is for:
Harman P68 (Pre serial # 008280309)

Harman Auger part # 3-50-00465 This part measures roughly 10 1/2" from end to end
P68 (Pre serial # 008280309)

 

[rickwai]

I think it is just a change they made when they redesigned the ultra feeder. It just runs faster for a shorter period of time. Do get the same amount of pellets in. I cant see a advantage unless it just works better w/ the new feeder design

 

[Don2222]

I think it is just a change they made when they redesigned the ultra feeder. It just runs faster for a shorter period of time. Do get the same amount of pellets in. I cant see a advantage unless it just works better w/ the new feeder design

Yes, according to one of my Harman Dealer friends, the new feeder has a smaller opening so a faster motor gets more pellets in to get the 68K BTUs on high.

What if you put the faster motor on the old feeder, do you get 75K BTUs on high on the older stoves?

However if you push unburned pellets into the ash pan then you still only get 68K BTUs

That is really beefing up an old stove!