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By seaco
#332540
This is the one that will do the job I, think I will have to swop out the motor from 3 phase to 240v though?

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By Jake
#332557
Is that the one from a garage?

I'd get a little inverter, the motor won't be huge and they are relatively cheap. Someone was advertising one on here not long ago, dunno if it was the right size or has gone.
User avatar
By seaco
#332559
Jake wrote:Is that the one from a garage?

I'd get a little inverter, the motor won't be huge and they are relatively cheap. Someone was advertising one on here not long ago, dunno if it was the right size or has gone.


Hi Jake I'll have to look into that... as you may have guessed I'm completely green when it comes to motors/electrics
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By big soft moose
#332660
lee has apparently managed to reject it with the buyer so I wont be buying this one as my motivation was more to help a forum member out than an urgent need.

on inspectors point I already have a record two fan chip extractor which does all i need in that respect - my extractor fan issue was to power a homemade fine dust extractor like that on some thread or other here. but thats a back burner project for as and when.... (sometime, never ;) )
By ivan
#332814
The best bet is a second hand booth; but like you I don't have enough room, and as a result have done a lot of research.

A good home made and fold away design can be found at the web site of the US dealer Highland Woodorking's info section. Mine is based on this. The airflow over the whole face of the booth needs to be no less than 2ft/sec. If your (small) booth is only 3x4ft, that's 2x3x4= 24cuft/sec or 1440 cu ft min. Bear in mind the resistance of the filter media will reduce the airflow. For a cheap fan and the folded concertina (see pic above) type filter, the fan will need to pull about twice 1440 cu ft min = 2880 cu ft min in free air (ie. no load)

A 14 inch Clarke plate fan is near this figure, but is not explosion proof. It is an induction motor, but single phase motors have a capacitor which will get hot and smoke (virtually ignite) when it fails. If the blades are steel, an accidental spark may be caused, and organic vapour/air mixtures explode. Your insurance company won't like what you have been doing (the firemen will find you out) and the cost of repair will be all yours, if you survive the bang. Better use waterbased finish, or pressurize your booth with the fan outside the room in clean air

My folding booth has a face of 2Mx1,8M abd I was lucky enough to find a second hand explosion proof booth fan for 100 quid. However this is 3 phase, like all the other s I have seen.
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By seaco
#334031
Me back again, I'm still looking for this bl**dy extractor fan I have come across this one the chap says he's used it for 2 pac paints and laquers etc. and that it's flame proof I'm not so sure it apparently says IP55 on the label and on looking that up it seems to state that IP55 means dust and waterproof, what do ya recon?

It says Sifan I think on it, and on looking them up I can't find any info on this fan!

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By 9fingers
#334041
IP ratings and being flameproof/intrinsically safe are not the same thing; although high IP ratings will be associated with safer motors generally.

IP55 is not particularly sealed anyway and the motor has an internal overload protector which means there is a switch inside hence a source of ignition.
There is also a possibility that being single phase, it will have a second switch for the starting winding.

I suspect that certified explosion proof motors will mainly be 3 phase and you will need an inverter to run it on single phase. This is not rocket science and we can help with selecting one once you have the motor. It also will give you variable speed (up and down from nominal) with which to control the airflow should the fan not be well matched to your needs especially one that is too big.

If you want to take a pragmatic approach, then look at motors that are at least ip66 and are not in the path of the paint fumes e.g. a snail blower. Make sure they are also the type that have the capacitor in circuit all the time. i.e. when they switch off you do NOT hear a click of the centrifugal switch.

hth

Bob
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By seaco
#334110
Thanks bob

What do you think of this one seems to fit the bill but is 3 phase surely converting it to run on 240v and making it variable speed is going to add considerably to the cost, we are only hobbiests and need the to keep costs under control?

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By 9fingers
#334286
seaco wrote:Thanks bob

What do you think of this one seems to fit the bill but is 3 phase surely converting it to run on 240v and making it variable speed is going to add considerably to the cost, we are only hobbiests and need the to keep costs under control?

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One essential thing to look for on a 3 phase motor is the ability to run on 240v. normally the rating plate will say |something like VOltage: 220/415 or perhaps 240/440. This type will be OK
If as the photo shows, 415 only, then there is a doubt that can be resolved by taking the lid off the junction box.

If inside there are 6 terminals usually in two rows of three, then it is very likely to be dual voltage. if there are only three terminals then it is little use for your application.

There are some inverters that produce 440 volts from 240 input. These are more expensive and harder to find.
If however you have managed to pick up a single voltage motor for next to nothing, then clearly there is more in the budget to put into the inverter.

Now to the fan, the one you show is very likely not to be vapour tight because of the belt drive will have to pass through from the motor to the fan. Yes your photo shows a belt guard but the motor shaft still has to get through into the shroud and this is unlikely to be vapour tight.

hth

Bob
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By seaco
#334301
9fingers wrote:If however you have managed to pick up a single voltage motor for next to nothing, then clearly there is more in the budget to put into the inverter.

Now to the fan, the one you show is very likely not to be vapour tight because of the belt drive will have to pass through from the motor to the fan. Yes your photo shows a belt guard but the motor shaft still has to get through into the shroud and this is unlikely to be vapour tight.

hth

Bob


Hi Bob

I think the easiest will be to swop out the motor for a 240v we have a couple about hopefully one will fit!

If you have seen the original pics I posted here the wall is an outside one so we were hoping to just enlarge the hole a bit then fit the fan to the wall on the outside then box around it with some sort of vent and we would make a grill and filter system of some find inside, could that work?





beech1948 wrote:seaco,

try following

http://cgi.ebay.co.uk/A-FERCELL-SPRAY-BOOTH-84-X-89-X-91-HIGH-SPRAYBOOTH_W0QQitemZ370147684239QQcmdZViewItem

alan


Hi Alan

They look fine but it's all to large and includes a booth which we couldn't use or even remove we only need a fan really...
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By 9fingers
#334316
seaco wrote:
9fingers wrote:If however you have managed to pick up a single voltage motor for next to nothing, then clearly there is more in the budget to put into the inverter.

Now to the fan, the one you show is very likely not to be vapour tight because of the belt drive will have to pass through from the motor to the fan. Yes your photo shows a belt guard but the motor shaft still has to get through into the shroud and this is unlikely to be vapour tight.

hth

Bob


Hi Bob

I think the easiest will be to swop out the motor for a 240v we have a couple about hopefully one will fit!




A single phase motor is highly likely to have a switch and hence a source of sparks. Round we go again!

If in your design the fan is only handling clean air ie pressurising the room and the paint vapours take some other route to the outside world then not a problem. If not then there is a risk that you need to feel comfortable with.

There probably is little real risk but we can't tell you that!


Bob
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By seaco
#334340
Well Bob we have made as many adaptions as possible (in our money range) to make it all safe so I think we will have to go with the 240v, that's if we manage to get the fan as it looks like it's going to go for a fair bit, if it does go cheaper than we think maybe we will look at an invertor of some sort but with the prices of those I doubt it...

Still it will be better than our original Vent Axia... :wink:
By ivan
#334360
The duct fan in the picture with external motor is the usual explosion proof set up. The 2nd hand one I got was originally supplied by Devilbiss. I got mine for 100 quid, fans alone often fetch 100's, more than complete booth!

The sealing round the belt drive is not always 100%, but provided any gap is on the input side, air will only be going into the duct, not escaping from it. I can't remember offhand the minimum distance for switches (outside the booth) etc from the front of the booth; a single phase motor would presumably also be regarded as safe at this distance as it would be outside the booth, likely round the back.

I think IP55 motors have a small hole somewhere as a condensation drain, not very helpful (re your plate fan) Blades must be of non sparking material. For a small booth, plate fan could push in clean air if motor on outside of booth. A couple of years back I sprayed a wall of built in wardrobes in situ pressurising the room with a 16" plate fan in window of adjacent room, + fibre filter rigged over door, and spraying room window.