remote gen fan

[christopher]

what brand model# and how many cfm should you use for the gen remote radiator?
thanx
chris
mci5c

[tekebird]

Brand?
Model?
CFM: Depends on the application

[Dallas]

That's an easy one...

It depends on Brand, Model, HP, fuel, output, cooling needs of the generator

[JackConrad]

When we remoted the generator (PowerTech 10 KW/3 cylinder Kubota) radiator on our MC-8 to the rear of the former spare tire compartment, we purchased the largest fan the would fit on the radiator. I think it was a 14" 2000 CFM, 12 volt. It was purchased on Ebay and was similar to this one
http://cgi.ebay.com/ebaymotors/PROCOMP-14-INCH-ELECTRIC-RADIATOR-COOLING-FAN-14-BLADE_W0QQcmdZViewItemQQcategoryZ33600QQihZ013QQitemZ230162167709QQrdZ1QQsspagenameZWDVW 
  We also installed 3   4" bilge blowers in the generator compartment (240 CFM each) to vent the compartment (PowerTech recommends a minimum of 400 CFM air flow through the compartment when radiator is not in the compartment).  Using the Temperature monitoring gauge, we have found generator compartment runs 5-10 degrees above outside air temps, whether running down the road or parked. This applies up to the hottest temps we have been in (102*).  Jack

[DavidInWilmNC]

Jack,

Do you have a way of keeping the gen. compartment fans on for a bit after the generator is shut off?  I'm thinking of a thermostat with a time delay (to keep the batteries from running down).  It'd be nice to get some of that heat out of the compartment.

David

[JackConrad]

Do you have a way of keeping the gen. compartment fans on for a bit after the generator is shut off?  I'm thinking of a thermostat with a time delay (to keep the batteries from running down).  It'd be nice to get some of that heat out of the compartment.


    That is what I am working today.  I am going to start by simply adding a switch that I can turn on to keep one of the 3 fans running to see how that works. I may have to use 2 or even all 3 fans.
    I have considered a thermostat set at 100*, but I do not want it to come on unless generator has been shut down. If bus is sitting in the sun on a 95-100* day, compartment may be 100+ and fan (s) would come on.
    I have also thought about adding a timer to keep the fans on for a set amount of time. That is probably what I will do and why I am running the test using a SPST switch to see how long the fans(s) need to run. 
     Anyone have any sources for 12 volt delay off timers?  Jack

[luvrbus]

Jack,when you solve this problem would you please post the results i try to use the thermostats that you buy for the fans at a auto parts but they won,t last but for a couple of months. You could check out Arizona Mobile Air i just haven't had the time to check glad you are working on this problem

[DavidInWilmNC]

Anyone have any sources for 12 volt delay off timers?  Jack

I think what you (we, actually) want are delay-on-break relays. 
http://www.artisancontrols.com/PGF-DOB.htm
http://www.airotronics.com/site/timing_delaybreak.php
and my favorite source for just about anything:
http://search.ebay.com/search/search.dll?from=R40&_trksid=m37&satitle=delay+on+break&category0=

It might be a lot easier / cheaper a 24VAC relay and a transformer off the generator output.  The 24VAC units are often used for HVAC... I bet Nick can give us some insight on these!

I assume this is what you want (it's what I'm planning, anyway):
When the generator is running and it exceeds xx°, the thermostat closes allowing the fans to cool the generator enclosure.  When the generator is turned off, the relay will keep power to the thermostat (via a relay) for a preset time.  The fans will run for this period or until it cools down inside the enclosure.  I don't think this will take much time to set up or be expensive at all.  It'll take me longer to rig up the fans than anything else.

David

[Len Silva]

To repeat something I've mentioned before, if you are using electric fans or blowers for remote generator cooling, I would include a sail switch for shutdown or just an alarm.

Len

[TomC]

I have the Powertech 10kw with 4 cylinder Kubota mounted next to the drivers seat like a front engine (transit).  The squirrel cage blower for the remote radiator and the 8" inline blower for ventilation is mounted under the driver's seat.  I used a single inlet squirrel cage blower from Graingers (2C986) that has the radiator mounted on the inlet side with a 1/2hp totally enclosed fan cooled 2 speed GE motor belt driven-high for during the day and low for quiet night time use.  I just came through Mojave desert on Monday and it was 107 degrees.  With two roof top A/C's going, it kept cool.  Tried three and the temp started to creep up, so just left the two roof tops on-which was comfortable.  I used an 8 inch inline wet area blower also from Graingers (DLX200) to draw fresh air into the tightly enclosed gen compartment.  The 8 inch outlet splits into two 6" inlets and have two screened 6" outlets on the back side of the gen compartment to exhaust the hot air.  So far, the system works well, and both blowers are 120vac operated.  Can run them extra when I plug into the power pole at a RV park.  Good luck, TomC

[H3Jim]

I have the 13 kw Wrico.  I added one of those slim line electric fans for use in hot rods.  3600 cfm.  Dick Wright suggests that I might want to keep a spare, that  it may have a short life. It does draw a lot of current.  Supposedly 10 amps at 12 volts.  I have to use 10 gauge wire and a 30 amp fuse to keep it from blowing.

The fan cools great, I have not had any issues in 3 years - although only about 50 hours of usage.  I haven't bought a spare yet, I hope Dick is wrong.  He recommends the squirrel cage fans.

[christopher]

guys
thanx for the imput
i have one side of the gen exposed to the outside but i guess that is not enough
the water temp says 180 but it shuts down at 160. wrico said it was not a faulty temp sending unit that i need to get air over the gen. i have a slim radiator fan dont know what the cfms are.
chris

[tekebird]

you need to either duct the incoming air or the outgoing air.

chances are you are just circulating the heated air over and over with very little cool coming in or hot going out

[akbusguy2000]

Spal makes a variety of wiring kits designed to power aftermarket fans - with or without relays, thermostats, etc.  Here's one source:

http://www.jaycorptech.com/showcategory.aspx?categoryid=19

tg