[encantotom]

hi all,

for several years, the internal fans on my prosine 3000 have not worked.  then it overheats and you get alarms at the control panel.  it started 2 summers ago.  being the redneck engineer that i am, i put a 10 dollar walmart desk fan in front of it and it ran continuously for over a year.  then it failed and i put another exact fan there.  it has ran for over a year nonstop now as well.  but....if there is a large load on the charger, it still overheats.  

xantrex prosine was an innovation at the time that didnt use the large torroidal transformers.  it was a solid state inverter.  it weighed almost half of the current ones.  it apparently was also outsourced and is considered and has been considered non-repairable and they will not work on them.  also, they will not release schematics or anything about them.  

i found someone online had taken a picture of the guts and i was able to zoom in and get the model number of the 3 whisper fans that are inside.  i bought them a long time ago and decided i would see if i could fix it.  

it is simple.  if the dc voltage to the fans is there, then just replacing the fans should be good.  if not, it will likely be a replacement with a new more modern one.  but they dont fit is the same spot and are larger...ugg

so this morning i took the prosine out.  remember, i am the size of sasquatch and it is mounted on the wall in a bay.  i had to take out the built in vacuum, and figure out how to get it off the wall.  kind of like a jig saw puzzle.  after an hour or so i got it out.  fortunately i am in the shop and have good lighting and a big48" fan i put pointed into the bay.  it is hot and humid today....50% humidity here and 105 is yukky for arizona.  

next is to take it apart and see what i can do.  

tom

[encantotom]

i think i am committed now.  i have no idea how they put this zillion piece puzzle together.  bt i just kept taking things apart until i could get to the fans.  getting it back together will be considerably more difficult.

good news is all three fans were bad.  two were seized and were hard to turn by hand and the other would work and spin slowly for a few seconds and then stop.  

so, i will wire in 3 new fans and get it back together and re install it and see what will happen.  

tom

[encantotom]

there were 50 screws that held the case cover on it is in 3 pieces. the case cover is also the heat sink so there are tons of screws to bond the cover to the different things inside that get hot.

it wasnt very dirty inside. i expected it to be thick with dust but it wasnt.

tom

[Fulltiming]

Not that you are an expert, we will have to replace the fan/fans in mine next time we are out your way!! So far the desk fan approach seems to be working for me.

[RussWhite]

I think I might have tried a different internal fan considering the history of Prosine's choice. I like your size description- although I doubt I could have spelled Sasquatch!

[encantotom]

inverter fix update.  

russ,  as you can see, there really isnt any room or ability to put a different kind of fan in it.  there are pictures of the old and new fans below and if you do the math you will see the ones i put in are a little more powerful than the old ones.  

i can say this is not something for the faint hearted.  i could do it now in 3 hours or more but i assure you it took me way more than that this time.  fortunately my inverter was only mounted a couple of feet in from the bay door.  i did have to take the vacuum out to get at it though.

i soldered and heat shrinked the wires for the new fans to the wires for the old ones.  i left way more wire than they had previously and just zip tied up the excess.  

some of the bolts holding it together you cannot reach the way i did it on the bottom side so i used shop surgical instruments to hold the bolt up until i had it together and put the nut on.  you can see them in the pictures.  

one of the things to remember if you take out a prosine is that the mount on the wall stays there and the inverter hangs on it after taking the 3 bolts out on the bottom.  then you loosen the 3 on the top and lift the inverter up and off the wall mount rails.  

i tested the old fans and they were for sure bad (and very hard to turn by hand) and the new fans are bearing ones that will spin by blowing on them.  i bought the fans a while ago and dont remember where i got them.  but just match the ones that are in it.  80x80x25mm computer fans cw rotation.  at least 40cfm and similar amperage or wattage....the old ones were 3000rpm and .13a   the new ones were .23a.  i have to believe that big inverter can power an extra quarter amp dc...

i had no way to test the inverter on the bench because the fans come on under load by a temperature sensor and not just when it is operating at low temps.  so i put it all back together and installed it in the bay and turned it on.  the fans did not come on until it was getting warm and then all three fans started purring.  

i guess the test is that of time and if they keep it cool enough.  

the last picture is of the sr71 print my son got me over the tv and home theatre in the man cave in the shop where i am sitting as i write this.  if you zoom in you can see the newell through the window behind me...

life is good.  

a 20 dollar fix rather than 2k.

tom

[Fulltiming]

That is not a bad hourly wage rate even if it took you 8 hrs.

[Chester Stone]

Neat job Tom, and good instructions for when the time comes.