Space Heater problem

[printcom]

Just wondering if anyone has any ideas. I have a 28Kw (Model 30) Andrews space heater which I purchased new in 2005. It hasn't done a lot of work maybe 20hours all told, I dug it out the other day as my indirect one went belly up and found it had developed a problem. It runs fine for about 5 min and then the fan motor slows down and stops working. I have pulled it apart a all seems to be OK, I have checked the air pump clearances and set the air pressure to what it should be but the problem keep repeating.
I am beginning to think it might be an electrical issue - any ideas?

 

[fizzy]

Try turning the fan blades with a stick or something or blow compressed air on them when it turns off. The bearing may be seizing up due to the heat. If the blades spin free then it isnt that obviously. Sometimes motor windings break down with heat as well.

 

[brightspark]

if u can get it out easy and its 240 volt run it off the machine and see what happens and oil the bearings while its out

 

[captain-destructo]

if you cant get it sorted
you could try one of these no electrickery needed

and it just so happens i have some for sale

 

[printcom]

I 've checked the motor bearings their OK. I think I know what the problem is, I just cant get my head round how to fix it. There is an air pump at the rear of the fan motor, Ive stripped it down cleaned it and put it back together ( i can't see any excessive wear) correctly gaped the impeller 6thou, trouble is as soon as I snug up the cover retaining bolts it all goes tight. I have tried lightly lubricating it with silicon oil to no avail. I am leaning towards skimming a few thou of the impeller unless someone has any other suggestions.

 

[printcom]

It never ceases to amaze me how easy some jobs are when you actually know what you are doing. I had a chat with my local Andrew Sykes branch this morning and a very helpful chap explained the the silicon oil I put on it is the main issue. Apparently, the casing, rotors and vanes must be very clean and dry and also gaped correctly. A good idea is to gently rub the rotor down on a bit of fine abrasive paper clean with brake cleaner and put back together. Hey Presto all works great.
I love it when a plan comes together....

 

[captain-destructo]

I love it when a plan comes together....

i hate the way my brain works

A TEAM theam music bouncing around my head now