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ooh ! I might have a question for Sir Bob ! extractor motor

PostPosted: 25 Aug 2016, 20:38
by Tusses
SIP dust extractor ..


I'll have a look myself 1st ,when I get a chance, and report back

symptoms so far .. not used it for a couple of weeks
pressed play and nothing .. hand on motor, I could feel it trying.
hose off, and spin the fan with a pencil up the hole, and the motor slowly spins up , but doesn't get very fast.

1st though was the cap .. but I hadn't noticed before .. no cap ?

I'll take the lid off the box when I get a chance, maybe a small cap inside ? .

either way, I'll report back :-)

Re: ooh ! I might have a question for Sir Bob ! extracto mo

PostPosted: 26 Aug 2016, 07:41
by 9fingers
Extremely unusual for there to be no capacitor on all but the most feeble of induction motors. More info needed to prevent unnecessary speculation.
I'll be otherwise occupied most of today but will look again on Saturday.
Bob

Re: ooh ! I might have a question for Sir Bob ! extracto mo

PostPosted: 26 Aug 2016, 20:26
by Tusses
no hurry Bob .. I have to get the down time to stop and take the switch cover off and have a looksee

this is as much as I know so far

Image

Image

Image

Re: ooh ! I might have a question for Sir Bob ! extracto mo

PostPosted: 26 Aug 2016, 22:13
by 9fingers
I'd put money on there being one if not two capacitors inside that box underneath the the NVR switch.

Bob

Re: ooh ! I might have a question for Sir Bob ! extracto mo

PostPosted: 26 Aug 2016, 22:28
by Tusses
when I get round to looking at it, can I raid my scrap/spars bin for caps ? .. mostly audio/psu , or do starter caps have some other peculiarities ?

Re: ooh ! I might have a question for Sir Bob ! extracto mo

PostPosted: 26 Aug 2016, 23:03
by kirkpoore1
Tusses wrote:when I get round to looking at it, can I raid my scrap/spars bin for caps ? .. mostly audio/psu , or do starter caps have some other peculiarities ?


You have to look at the ratings in voltage and microfarads (uF). Anything over 240v will be fine, but the capacitance should be reasonably close to what's in there.

Kirk

Re: ooh ! I might have a question for Sir Bob ! extracto mo

PostPosted: 27 Aug 2016, 08:05
by Tusses
I was thinking more of polarity issues ?

Re: ooh ! I might have a question for Sir Bob ! extracto mo

PostPosted: 27 Aug 2016, 08:12
by 9fingers
Indeed. Electrolytic capacitors are no good for this application and I would go for voltage ratings around 400v.
Motor capacitors are very cheap on eBay and you are possibly better off with a new one.
Bob

Re: ooh ! I might have a question for Sir Bob ! extractor m

PostPosted: 16 Sep 2016, 17:31
by Tusses
finally took the cover off ...

As you said Bob, there it is in the casing

Image

Image

Looking on ebay they're about £3.50 .. like this ..

http://www.ebay.co.uk/itm/Universal-10U ... SweWVXf~Vv

what do the numbers mean under the 450VAC ?
Mine says 40/70/21

the ebay one says 25/70/21

??

Should I just buy the cheapest ?

Cheers
Rich

Re: ooh ! I might have a question for Sir Bob ! extractor m

PostPosted: 16 Sep 2016, 20:00
by DaveL
I think those numbers are the climatic ratings for the capacitor, the first is the lowest temperature -40 , the next is the highest temperature +70, but I cannot find the last one defined, sorry.
So the replacement one you are looking at will be OK a so long as you don't move to the north pole.

Re: ooh ! I might have a question for Sir Bob ! extractor m

PostPosted: 16 Sep 2016, 20:39
by 9fingers
+1

Bob

Re: ooh ! I might have a question for Sir Bob ! extractor m

PostPosted: 20 Apr 2017, 17:25
by Tusses
well , it's been a while !

whilst I re-cooperate, I've been fixing stuff.

Finaly go round to putting that capacitor in.

It ran great for about a minute and then broke again. motor slowed, and made an unpleasant noise.

I'm guessing the start/run switch , inside the motor is the cause ?
If so, are these cheap motors serviceable ?

Re: ooh ! I might have a question for Sir Bob ! extractor m

PostPosted: 20 Apr 2017, 18:52
by 9fingers
Open it carefully and you might find the switch is fixable. Take it steady and observe how the mechanism works and which way round things go (photos to document) WATCH OUT FOR PING-**CKITS

You almost certainly cant get spare parts for these switches but sometimes you can fashion parts out of phosphor bronze sheet.

Bob

PS what is the big white lump with the black leads coming out?

Re: ooh ! I might have a question for Sir Bob ! extractor m

PostPosted: 20 Apr 2017, 20:30
by Tusses
the white lump is the cap in a sleeve

I'll make some workbench space before I attempt dissmantlement

Re: ooh ! I might have a question for Sir Bob ! extractor m

PostPosted: 20 Apr 2017, 20:37
by 9fingers
Tusses wrote:the white lump is the cap in a sleeve



Ah OK the crease is the sleeve made it look like a rectangular block.

Bob