HOT inverter... repairs.

[birdhouse]

hello-
i run a 24v xantrex prosine 1800 at my offgrid ranch.  i bought it used and have been VERY happy with it for the last 2 years until it recently.  it has been going into "system shutdown" when loaded hard. 

i noticed the long duration medium to heavy loads were tripping it out.  then i noticed the case was kind of hot, yet the fan wasn't running.  i did a stupid quick test and hot glue gunned a 24v muffin fan right over the top of the non-working oem fan and wired it right to the bank.  presto, the prosine cooled and would run everything it used to without issue! 

so now i'm stuck with leaving a hot glue gunned fix that runs the fan the whole time the inverter is on, or trying something else.  the fan that doesn't work (oem) does spin freely, but i didn't have time to pull the case and dig any further. 

is it common for factory inverter fans to die?  or maybe the circuitry (thermostat) to turn it on/off has died? 

might it be easier to add an aftermarket thermostat to a new fan rather than fixing the thermostat in the inverter? 

just curious as to weather any of you have had similar problems, and what you did to remedy the situation. 

i'm not very good at small electronics, but aren't most thermostats 24v?  could i use one of them to control the fan without relays, ect, as the fan load is very small?  or would the thermostat use more juice than the muffin fan running 24/7?? 

i've found some 24v muffin fans that pull around 4 watts that i think would do the trick. 

thoughts?

adam

[joestue]

yes, it is common for fans to die.

can you poke volt meter leads through the wires leading into the fan? if its got voltage on it i'd rip it out and replace it.

if not then you'd have to poke around on the board to fix the thermister/opamp/transistor etc.

[SparWeb]

Hot glue:  you've taken a page from the Ghurd Book of Electronics Repair.

If there's a voltage across the fan's leads, when the inverter is loaded and hot, but the fan isn't turning, then it's probably the fan's fault.  You don't have much to lose if you just cut off the leads of the old fan, and splice in the leads to the new fan.  Mounting the fan in the old fan's spot requires matching holes, space in the case, etc., but maybe the hot glue on the outside approach is fine, too.

If no fan will work, because the leads from the board aren't powered at all, then a different approach is needed.  You could get a snap-disk thermostat that trips ON above 50C, roughly, and off below 40C, and attach it to the inverter's outer case, or some other convenient spot that will get hot under high load.  Use heat-sink thermal grease, not hot glue.  This thermostat, in series with the hard-wired fan's power supply, will prevent it from running when the inverter isn't hot.  I don't have a thermostat catalog in front of me, so I don't know if that specific temperature range is available, but something close will do.

[thingamajigger]

@Birdhouse
All fans, muffin or not will crater at some point as all mechanical things will ---  it is simply a matter of time. I would get the factory part number and order a new one, well actually "I" wouldn't  . Many times electronic devices use cyclic on/off controls which are archaic and no real energy efficient device uses this control scheme anymore. Anything I build has variable speed control using cheap circuits so that if the heat load is 10% then the fan load is 10%, not 100% or zero, the fans last way longer and use less energy.


here is an easy circuit which will work ---- http://www.devhardware.com/forums/pc-cooling-8/howto-homebrew-fan-speed-controller-283464.html
See section 2 Automatic Speed Control

Regards
Thing

[Bruce S]

Thing
So that's where my wire wrap tool got of to 
Nice circuit, I'm tempted to build one just because.
Bruce S

[birdhouse]

thanks all for the info! 

yes, i have followed in ghurds footsteps when it comes to using hot glue!  if only i had his elec. knowledge as well!   

i had just learned the fan wasn't working and was in a rush for our annual party, and thus the hot glue to keep an aux fan attached to keep the unit cool while brewing 6-8 pots of coffee per morning...   no one enjoys their coffee if it took a genset to brew it! 

i'll try replacing the fan, as that would be best.  if that doesn't work, i'll look into snap disks ect. with an aux fan. 

FYI:  the party was a huge success!  100+ folks, 10 kegs, turbine tower raising, 4 live bands, no a$$holes and a jolly good time!  my system is small compared to many here, so a 5500w coleman genset was used for the amps, PA ect.  the little prosine and my batterry bank did great with the house lighting, LOTS of coffee, a cell phone charging station, and cordless tool chargers! 

adam

[SparWeb]

Now, THERE is the important part of the story. 
Hosting a party with live music (FOUR bands?!!) is no small job. 
Pulling it all off with RE power is an accomplishment worthy of the front page.

FYI:  the party was a huge success!  100+ folks, 10 kegs, turbine tower raising, 4 live bands, no a$$holes and a jolly good time!  my system is small compared to many here, so a 5500w coleman genset was used for the amps, PA ect.  the little prosine and my batterry bank did great with the house lighting, LOTS of coffee, a cell phone charging station, and cordless tool chargers! 
adam

[spottrouble]

the party was a huge success!  100+ folks, 10 kegs, turbine tower raising, 4 live bands, no a$$holes and a jolly good time!  my system is small compared to many here, so a 5500w coleman genset was used for the amps, PA ect.  the little prosine and my batterry bank did great with the house lighting, LOTS of coffee, a cell phone charging station, and cordless tool chargers! 

adam

Sounds like great party

Kristi