Using UK 110V Kapex 120 with 240V Midi dust collector

[PJGWiltshire]

I am looking to buy second hand Uk 110 V Kapex 120 saw and Rotex 90. I will be running these through a transformer. Does anybody know if plugging the transformer into the 240V Midi will still make everything work correctly when the saw/Rotex are started up (ie the auto start for the vac)

many thanks

 

[Distinctive Interiors]

As soon as you plug the 110v transformer into the outlet socket on the Midi, the dust extractor will start running if you have set the switch on the Midi to Auto.
It will make no difference whether you have plugged a 110v tool into the transformer or not.

The transformer will draw enough power on its own to trigger the Auto start function on the Midi.

Tim.

 

[Womble]

This is really not a good idea...

If you plug a transformer into the Midi & its set to "auto" it is just going to run the Dust Extractor 100% of the time & not shut off until you unplug it. If you set the Midi to Manual it will still run the Transformer but you will need to manually start & stop the dust extraction. Also the amount of current 110v Transformers draw especially with bursts really wouldn't do the Midi any good especially with how fussy they are with power supplies even when being run normally.

Can i ask what you're trying to achieve with this sort of set-up?

This isn't going to work as a Site set-up regardless as you would still need a 240v supply which youre not going to get on a site, surely it makes more sense to just purchase as 110v Midi and run that off a transformer. I run my Midi off a 110v Transformer unless on site in which case i use the 32Amp outlet on the site power distribution boxes and then a fly lead to drop down to standard 16Amp 110v cables as TBH the Festool is a pile of crap on long 110v cable runs and is like an elderly asthmatic gerbil is powering them, this issue is amplified when running things like TS55 via a Midi so best to keep cable runs as short & possible & used 2.5mm 110v cables not 1.5mm.

 

[PJGWiltshire]

Many thanks for the useful info. I am not a site worker just keen hobby /DIY who has a lovely wife but loves his Festools more(Glad she don't read this site its and age thing!!!!).

I got a couple of drills then the T55 and a sander all using the Midi. Have an opportunity to pick up the Kapex and Rotex in 110 V half price thats why I ask re the 110V through the Midi

Shall have to give some thought to manual running without the auto

 

[Womble]

ok, if you not already purchased the 240v Midi i would looking at getting a 110v Midi & just running everything properly with a 110v transformer powering the Midi & the 110v tools off the 110v outlet on the Midi then you can use the Auto as intended then also if powering a 110v Midi & you got some 240v tools you can just power them both up separately on the respective power & hook up the dust connections & just manually turn it on for the 240v tools.

There is other options you may want to look at like the iVac remote power sockets which Toolovation sell (site is currently down though) but they are a first class supplier with absolutely superb customer service & do various other Festool accessories just an FYI like the rare Collins Jigsaw Bases & many other very unique & hard to source things in the UK.

 

[PJGWiltshire]

Thanks, just looked up the IVAC on their E bay site. Clever idea aged option when using the 110V tools?

 

[PJGWiltshire]

Just been reading up on the IVAC, would Not still have the same problem if I plugged my MIDI into the IVAC along with the transformer for the Kapex or Rotex. If by so doing directly into the MIDI it would run straight away, will this not happen when the transformer is plugged in.

 

[thudchkr]

Am curious. Is the transformer you use to step down to 110 something more than just a transformer with connectors for input and output? Normally, an AC transformer will not use any current on the primary unless something is pulling current off the secondary. When voltage is applied to the transformer it creates the magnetic field for the secondary, but without a load there, the field never collapses so there should be no current flowing at that point.

I would have expected that the transformer wouldn’t trigger the dust extractor unless there was an item actually in operation on the transformer.

However, I don’t know if there is additional circuitry in your step down transformers that use power all the time they are connected,regardless of whether a load is applied to them or not. If they don’t use power when no load is applied, I would think a transformer then shouldn’t trigger the extractor by itself.

Has anyone tried plugging a transformer in, without a load, by itself and had the extractor run?  I’m not saying it doesn’t do so, but trying to grasp why it would, based on what knowledge I remember about how transformers operate.

Thanks. Enquiring minds want to know.

 

[Womble]

These are UK site transformers we are discussing.

In the UK we have to use 110v tools on commercial projects which is different from the standard 240v used in homes & office. The plug types are totally different & also the voltage/amps. When working on sites they are either wired out with 110v distribution boxes located at various locations throughout the buildings or you have to use generators. When at domestic properties you need to use a 110v transformers plugged into a 240v socket. This is a typical examplehttps://www.axminster.co.uk/110v-site-transformers-ax23256 these draw power continuously & also easily trip lots of MCBs in domestic fuse-boards if they are not of the Type C or D due to the inrush of current when initially plugged in.

Many tradespeople who do not do any site work in the UK just purchase 240v tools eliminating the need for 110v transformers. But if you do any commercial site work this is not an option as you will not be allowed to use the tools, this isn't actually a Law but more a standard that has been adopted over the decades & is just the situation thats been uniquely created in the UK but hey ho it is what it is.

 

[Bohdan]

When voltage is applied to the transformer it creates the magnetic field for the secondary, but without a load there, the field never collapses so there should be no current flowing at that point.

The current in the primary sets up a magnetic field in the transformer and when the sine wave reverses thru the other half of the cycle a reverse magnetic field is generated. Unfortunately the steel in the transformer core has a property called hysteresis which results in the magnetising effect using or losing a small amount of power.

I think that that small amount of power is enough to trip the CT.

Very good quality magnetic steel has a very small hysteresis effect but that steel is expensive so it might be that the better quality transformers may not trip the CT but the only way to find out is to try the particular transformer that you intend to use.

 

[thudchkr]

So, evidently, these transformers are always using some power when connected to mains. As such, I agree they would cause the extractor to run. As long as that was enough current to trigger the extractors circuitry.

I would be taking a transformer to a Festool dealer and trying it there before buying myself the 220 extractor, in a situation such as the OP was considering, based on my belief on what I expected to happen. (Actually, I would have probably gotten the items and then been dismayed if they didn’t function as expected.)

Thanks for the responses.

 

[Job and Knock]

I really wouldn't go there. I think that a 3.3kVA transformer (really the minimum you should be running a Kapex on, alone) will potentially draw enough power on startup to fry the circuitry in a CTL over time, or worse fry the electronics in the Kapex. As said elsewhere the transformer is "lossy" and will draw current all the time it is plugged-in. At the end of the day it is effectively a type of heating coil - feel one at the end of a session and you'll know what I mean - and that heat is just electrical energy being converted into heat. Go the other way, to a 110 volt extractor, and you really do need to look at either a 5kVA or 6kVA transformer to run both the vacuum and the Kapex simultaneously - unless you like the idea of frying your Kapex electronics. And we know all about that issue on FOG

Very good quality magnetic steel has a very small hysteresis effect but that steel is expensive so it might be that the better quality transformers may not trip the CT but the only way to find out is to try the particular transformer that you intend to use.

These are UK site transformers, so whilst that is a nice idea in theory, that's all it is. A theory. These items are always built down to a price - not up to a standard

 

[PJGWiltshire]

Well thats made my mind up. Your clear advice has sent me back to 240v all round. So although there are some good young second hand Festool110V power tools i out there in the UK, I shall not get them. Looks like I shall extend Dry January- Dry February into a Dry March and the saved pennies will buy my Kapex120

Thanks for the most useful heads up on my first post.

 

[Distinctive Interiors]

As I said in my original reply, I have tried 2 different transformers on all 3 of my CT extractors (CT11, CT Midi and CT26) and they all start,
no matter whether there is a tool plugged into the transformer or not......!!!