What external fan to use to cool Alternator

[Seychelles]

Yes, in the back and out the front makes sense from the standpoint of cooling the belt sheaves. Unfortunately, I did not have room in the back of the alternator for a blower. I assume my setup works because the blower cycles on under heavy loads and cycles off periodically, preventing the ramp down circuit in the regulator from kicking in. Mounting the blower in the back may be better if you can do it.

[Ram]

Great Ideas, Seychelles
Inow have the fan and the duct work done and will add the thurmostat,
now I installed this whole setup on June 1 Balmar 120 apm alt with a MAX CHARGE balmar regulator, the regulator failed after 3 months or so , now its out of warrenty because i did not get around to instaling it in time,
anyone have a recomadation on where to buy a new one or is it posssbule to have this serviced?

[akopac]

I'm going to throw these links in here for anybody in the future who hits this thread:

Cool your alternator - Ocean Navigator - March/April 2011

http://www.zrd.com/faq/esdfaqaltcooling.html

http://www.zrd.com/

[Sternwake]

Does anybody have actual Data on how much an external fan on an alternator can pull through the alternator?

I am working on a 'remanufactured' Automotive 50/120 chrysler/Bosch whose slip rings were not set right and the lower brush was able to contact both slip rings.


I decided to rehone the slip rings by using my angle grinder with a cloth buffing wheel, on a Router speed controller, touching the external fan to spin the rotor.

I am not exactly sure how fast I got the rotor spinning. The grinder is rated at 11K rpm and the buffing wheel is smaller than the alternator fan diameter and I was running it upto speed 6 of 10 on the router speed controller. I will guesstimate it was in the 4.5 to 5K rpm range.

Being a bit of a ventilation enthusiast I was quite disappointed at how much air the alternator's fan was moving, although with air it exiting radially it is hard to tell.

This alternator's 50/120 'nippondenso' replacement is proving to have 20% worse output at hot Idle speeds, but just 75 rpm more and it is capable of that 50 amp rating 62 amps at 600 hot engine rpm. but only ~38 at 525 hot engine rpm.

I've been considering feeding the alternator with powerful 12v computer fans.

[akopac]

Anybody know where you can get a fan assembly like the one on the upper left of this alternator on a Perkins 4.108?