Nickp
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| posted on 23/11/12 at 07:57 PM |
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Reversing a 240v extractor fan?
I've been given a nice big Vent-Axia extractor fan to put in the back wall of my garage extension. Just stuck a plug on it and it's
blowing the wrong way, so the electrical gubbins would be on the outside of the wall and exposed to the elements. The rear of the motor has 4
terminals with only 3 in use (L,N,E). L is currently connected to A0 and A1 is spare. Is it as simple as swapping the live over to A1 to get it
spinning the other way? Or am I about to blow the thing apart in spectacular fashion?? 
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daniel mason
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| posted on 23/11/12 at 08:04 PM |
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think yove got a window fan. can you fit it on the outside wall instead?
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steve m
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| posted on 23/11/12 at 08:08 PM |
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turn the fan round the other way ?
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Nickp
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| posted on 23/11/12 at 08:10 PM |
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quote:
Originally posted by steve m
turn the fan round the other way ?
First thing I thought of but unfortunately it won't 
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big-vee-twin
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| posted on 23/11/12 at 08:33 PM |
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Can you get the fan blades off the motor and mount it on the other way round
Duratec Engine is fitted, MS2 Extra V3 is assembled and tested, engine running, car now built. IVA passed 26/02/2016
http://www.triangleltd.com
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Nickp
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| posted on 23/11/12 at 08:36 PM |
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quote:
Originally posted by big-vee-twin
Can you get the fan blades off the motor and mount it on the other way round
Unfortunately not. The only options are to get it spinning the other way or get another one.
[Edited on 23/11/12 by Nickp]
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owelly
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| posted on 23/11/12 at 08:53 PM |
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Disconnect the live and see if there's continuity through the spare terminal. If there is, connect your live to it via a piece of 2amp fuse
wire. See what occurs!
http://www.ppcmag.co.uk
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Nickp
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| posted on 23/11/12 at 09:25 PM |
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quote:
Originally posted by owelly
Disconnect the live and see if there's continuity through the spare terminal. If there is, connect your live to it via a piece of 2amp fuse
wire. See what occurs!
Will do, you may hear the bang in Whitby 
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I predict a Riot
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| posted on 23/11/12 at 09:42 PM |
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It is more than likely a shaded pole type motor and therefore designed to only run one way.
Sorry
"Honesty is a very expensive gift. Do not expect it from cheap people ". Warren Buffet on Expectation
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Nickp
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| posted on 23/11/12 at 09:44 PM |
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quote:
Originally posted by I predict a Riot
It is more than likely a shaded pole type motor and therefore designed to only run one way.
Sorry
Maybe, but why the extra terminal then?
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mookaloid
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| posted on 23/11/12 at 09:58 PM |
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quote:
Originally posted by Nickp
quote:
Originally posted by I predict a Riot
It is more than likely a shaded pole type motor and therefore designed to only run one way.
Sorry
Maybe, but why the extra terminal then?
Possibly the permanent live for the timer run on function?
"That thing you're thinking - it wont be that."
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I predict a Riot
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| posted on 23/11/12 at 10:01 PM |
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I've checked my vent axia cataloge and they no longer use that terminal notation so I really don't see why you can't try connecting
the live to the spare terminal and see what happens.
You might get lucky!
"Honesty is a very expensive gift. Do not expect it from cheap people ". Warren Buffet on Expectation
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unijacko67
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| posted on 24/11/12 at 08:36 AM |
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If you have room you could mount it to a bit of ply with a hole in the centre, turn it around then box the sides in.
http://www.kittenkitcar.co.uk
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Peteff
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| posted on 24/11/12 at 08:44 AM |
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If the blades are designed as a pusher it will not be efficient if you just reverse the motor. It will move air but not like an extractor fan. The
spare terminal looks like another neutral shielded from the live and will be a dead short if you put the live in it. I would put the neutral in it
first and see what effect it has.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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Nickp
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| posted on 24/11/12 at 09:20 AM |
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quote:
Originally posted by Peteff
The spare terminal looks like another neutral shielded from the live and will be a dead short if you put the live in it. I would put the neutral in
it first and see what effect it has.
You may be right. A0(L) and A2(N) measure 250ohms between them, possibly through a winding? A0(L) and A1(?) measure exactly the same. So, in theory it
should be safe to connect the N to A1 and see what happens. It kinda makes sense too the way it's wired making it easy to swing the N between
the terminals. Any more thoughts before I blow it up?
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bi22le
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| posted on 24/11/12 at 10:25 AM |
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Yeah,
Its been an hour, are you still alive?!?
Track days ARE the best thing since sliced bread, until I get a supercharger that is!
Please read my ring story:
http://www.locostbuilders.co.uk/forum/13/viewthread.php?tid=139152&page=1
Me doing a sub 56sec lap around Brands Indy. I need a geo set up! http://www.youtube.com/watch?v=EHksfvIGB3I
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westf27
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| posted on 24/11/12 at 10:36 AM |
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If its a shaded pole motor (solid rotor and surrounded by coil wound stator then you can reverse the rotation by flipping 180 degrees the outer
stator.If you look closeley you will see a shading ring to ensure correct rotation.
555
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Nickp
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| posted on 24/11/12 at 10:46 AM |
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quote:
Originally posted by bi22le
Yeah,
Its been an hour, are you still alive?!?
Yeah, because I've only been painting the wood work Still plucking up courage.
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Nickp
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| posted on 24/11/12 at 11:20 AM |
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It works!! 
TBH, I went to rewire it and noticed instructions inside the cover where they were terminated. Saying to swing N between A1 and A2 for intake or
extract, as we suspected anyway. Feel a bit daft but hey it's working now and thanks for all your help / advice
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MikeRJ
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| posted on 24/11/12 at 12:20 PM |
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quote:
Originally posted by big-vee-twin
Can you get the fan blades off the motor and mount it on the other way round
Putting the fan on back to front does not change the direction of airflow! It will simply make the fan less efficient assuming the blades are and
optimal shape.
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