Hi folks,
I need your advice. Does anyone of you has a good idea for a reliable, silent, approved cooling fan? I have some problems with my avionic ( GNS-530, GMA-340, GTX-330, Bendix/King KX-125 and Blue Mountain Avionics EFIS) getting very hot after about 45-60 flighttime. The EFIS starting with showing the temprature in Red and than showing “Overheat”. All the avionics is nearly hot at that time, so I think it is not ideal for a long life. Aircraft Spruce has some http://www.aircraftspruce.com/menus/av/coolingfans.html. I have the choice between cooling fans with 1, 3, 5 and 6 cooling ports. I prefere a fan with 3 ports. One port for the EFIS and 2 ports for the avionic rack. One left and right side. Yes and I need one for 14VDC.
Below a picture of my panel and one of the overheating EFIS. Please no discussion about the EFIS at this place! PLEASE!!!
Thank you
Is there no fan presently? That would be most unusual.
I think not. There is no switch and no fuse labled with avionic fan or so.
An avionics fan should come on with the master switch – because some avionics come on before the avionics master is turned on (e.g. EDM700 etc). But some fans might come on with the avionics master. No separate CB from what I have seen, but there may be a fuse.
Without a fan, these panel mount boxes will rapidly overheat. Your whole centre stack must be cooled, with an individual pipe running to the back of each slide-in tray. So my suggestion would be to look for an existing fan and maybe replace it. They do seize up. I have seen a couple of the KA33 ones pack up – these are probably the most common one used in GA
They are easily found on US Ebay for some $200. However, internally this fan is a piece of junk and probably the “reassuringly expensive” Sandia ones on that Spruce page will be better.
If you don’t have a fan, firstly you should shoot the avionics installer for extreme negligence and then you have a fair bit of work because you have to run the pipework to the backs of the boxes.
Ahhhhh …. I dont’ t have a avionic master switch. 
I know it’s not the perfect aircraft but it’s my. Yes it’s true, the EDM 830 comes on with the, let me say it in my way, normal master switch. All other avionics will be switched on one by one after engine start. Ok 4 switches. Do you think the EDM sustain damage if it’s powered during engine start? Sure all the Coms, Navs, Txpder, Intercom and EFIS are not powered during engine start or shut down. I own the Grumman for 3 years now and operating it this way. All was fine except the hot avionics I don’ t like.
So I consider the CYCLONE 600 – 6 PORT AVIONICS COOLING FAN or the SANDIA ACF 528 5 PORT FAN from Spruce. It’s a good chance for me to pick it up next month in Miami and save some money.
Installation will be done by my local maintenance. I have no heated hangar and I think it would takes at least 4-5 times longer if I would try it. I have no desire any more to work on the plane after my experimental Pulsar XP a couple of years ago. Belive it or not.
OK. I would still check there isn’t a fan in there, because that centre stack should not be functioning (in the summer) without one.
One of the reasons behind an “avionics master” system is that you can have a relay in there which opens when the engine is being started, so the avionics are protected from the starter motor transients which are pretty bad.
I don’t know about the EDM830 but there is this thread which is mostly inconclusive (seems like nobody knows the answer; I suspect it is just down to what the STC says) but the last post mentions the 830.
I have 5 port cooling fan that has become redundant due to fitting GTN650/GNC225 units that have internal cooling fans. Would come with am EASA form 1.
