3 phase help required (pretty please)

[OldWood]

I don't have Bob's mileage on this topic but I do know a bit about motors, 3 phase and invertors.

Don't even consider the single phase option - it;s a non-starter. I doubt you will easily get a single phase 240v motor that will supply 5hp, and if you did, the start up current will makes demands on your consumer unit, etc that it may not be built for. Add to that you've got to remove the existing motor, do the mechanics of fitting the replacement and cope with a shaft diameter change.

There are thereafter two options - the 240 to 415v 3 phase invertors which are more expensive than 240 to 240v 3 phase ones, but would not need the motor taken out and rewired. The re-wiring is quite straightforward, but it will cost a day's work for someone and there will be the hassle of getting the motor out and in, plus transport. I've done a 1 hp motor of similar vintage and this would just be a bigger version of that, and correspondingly more difficult to handle.

I'm pretty sure that you will need an invertor for the power of the motor, not for the theoretical input power. The invertor will cope with the start-up current and will anyway wind up the motor speed by increasing the frequency rather than just putting all the ac power straight on line so there is virtually no start up surge.

You will need to think about your ON/OFF switching and Emergency buttons. You will be dealing with a remote from the invertor set up which means control wiring and the likes, but there are panels for this on the market. Similarly any emergency switching will need to be taken into account. Bear in mind that the invertor needs to be switched itself by its control panel or remote box, and that it's not just a black box that sits there and responds to the 240v being fed to it - you power it up and then switch it to operate the motor.

Hope this is of some help.

Another company to look at by the way is www haydockconverters.co.uk. Having just looked at their site, it may well be worth you considering going down the rotary convertor route as it is cheaper for a fixed speed set-up, and has the advantage that it is far easier to use with several different machines. I've no experience in this but the option looks worth considering.

Rob

 

[roadman]

i am still a winner?

It depends mainly on the completeness and condition of the sliding mechanism and, if you will depend on it for your work, the scoring mechanism.
When scrit was around he reported that most panel saws released to the s/h market were spanked.

BTW, in the model in the ebay link the scoring saw is belt driven off the main saw arbour, so if your intended is also SP12 then there's only one motor to replace.
From the manual at Dalton's it appears the arbour spindle is only 17mm through the bearings anyway, so maybe repowering to 3 HP would be appropriate as well as less expensive (either way you go - straight to 1ph or to someone's 3HP 240v 3ph discard from a repowered AGS plus a VFD).
A VFD will deliver a soft start and ramped deceleration.
A 3 HP 1ph motor or 3 HP VFD will typically run on a 16A circuit, and BTW the 12 AGS/BGS/BGP and the steel cased saws have much more clearance for the external capacitor shells on a single phase motor, so are much easier to repower with 1ph than is an older iron 10 AGS.

A good point has been made about correcting the supply to other electrical components. This might be as simple as changing a tap on an existing control transformer. [edit: and changing an overload relay setting or changing out the heaters if going to 1ph; typically with a VFD the starter contactor and overload are taken out of service.]

From a quick run through the SP12 manual, it appears that the rise/fall mechanism and riving knife hardware are mostly made up out of the same parts as the AGS 250/300 and/or AGSP, so you can potentially use a less expensive Wadkin Bursgreen saw as a donor if you run into trouble with these subsystems down the road.
But elements of the sliding system, apart from any standard parts, will be incredibly hard to find, so on top of basic completeness of the rest of the saw (which mainly means riving knife hardware and the scoring saw) this should be your main area of evaluation of the specific unit.

Art

 

[chipchaser]

I wouldn't completely rule out a change to a single phase motor You should be able to find one similar to this one on ebay

ELECTRIC MOTOR SINGLE PHASE 240VOLT 4KW/5.5HP 1400RPM,
Buy it Now Price: £202.00
Item number: 200461407457

But you need 2800 rpm so you could watch ebay until one turns up or enquire at local suppliers. You might find that companies advertising on ebay have similar motors in both 2 pole (~2800 rpm) and 4 pole (~1400 rpm) versions in stock. I think its worth asking if you want to go along this route. I bought a motor from Motion Control in Bournemouth via ebay and they sent me the right power but wrong number of poles by error. They had both in stock but only advertised one type on ebay.

This draws 22.2 amps so will need a proper supply from your distribution board. However, that's not a particularly large current, ring mains are fused at 32 amps.

Just a thought

Graham

 

[roadman]

the way i am looking at this is, this one is 1650 plus vat

The prices struck for similar models from completed auctions are a more appropriate measure of the market. If I offered a like saw with a buy-it-now price of £10k would that make the one offered at 600 an even better deal?

On a more positive note, if you change motors the pulley switch is unlikely to be anything like the headaches Andy Dingley or Dave Laker had matching their pulleys with imperial-sized bores to newer IEC framed motors. The depicted plate on the Brook motor says frame D100L, which is a post-1974 standard on your side of the pond with a specified 28mm shaft, and the pulley should move straight across to a new IEC-frame motor with even a little care in its selection.

Art

 

[miles_hot]

Good grief that thing is a monster - you must have a fairly good sized shop Have you had a word with your electricity supplier about 3ph power? I would suspect that in the long run this could work out cheeper - as Moose says if you buy further 3ph kit you don't have the hassle of converting them.

Miles

 

[Anonymous]

it certainly is a big machine, but i need it to be so.

So the cheapest option is to get a new motor fitted? will i have any power problems with this?

Electronics are definitely murky waters for me so need all the help i can get, as i really don't want to be ripped off.

Thank you for all your help, it really is a massive injection of knowledge into the grey matter.

 

[Anonymous]

i don't have Bob's mileage on this topic but I do know a bit about motors, 3 phase and invertors.

Don't even consider the single phase option - it;s a non-starter. I doubt you will easily get a single phase 240v motor that will supply 5hp, and if you did, the start up current will makes demands on your consumer unit, etc that it may not be built for. Add to that you've got to remove the existing motor, do the mechanics of fitting the replacement and cope with a shaft diameter change.

sorry OW completely missed yours out, so a new motor is not an ideal way??

i need wizers dunces cap i am afraid!!!!!

Mark

 

[Karl]

i don't have Bob's mileage on this topic but I do know a bit about motors, 3 phase and invertors.

Don't even consider the single phase option - it;s a non-starter. I doubt you will easily get a single phase 240v motor that will supply 5hp, and if you did, the start up current will makes demands on your consumer unit, etc that it may not be built for. Add to that you've got to remove the existing motor, do the mechanics of fitting the replacement and cope with a shaft diameter change.

sorry OW completely missed yours out, so a new motor is not an ideal way??

i need wizers dunces cap i am afraid!!!!!


Mark

Mark - I wouldn't dismiss the new motor idea. The motor in my saw is 5hp single phase. Runs off a 16a supply.

Cheers

Karl

 

[OldWood]

Karl
Are you absolutely sure of your figures there? The reason I ask is that I have a 2.2kw motor on my saw which is nominally 9 amps peak running current and the start up on that on a 16A supply meant that I had to put in a type B MCB to stop it dropping out. And that's with an electronic starter with adjustable to timing to reduce the surge.

A 5 hp motor is 3.7 kw > 15.5 amp peak running current, and I cannot see how a 16A supply can be coping with the start up. You're talking anything up to 10X run current at start up.

Rob

 

[RobertMP]

Just wondering if buying a 2nd hand generator to run it from would be the cheapest option?

From the motor plate... 415 x 7.3 x 3 = 9088VA. The low power factor will mean that the watts drawn will be significantly less than that figure but the supply has to be up to those volts and amps which is why things are expensive.

You need expert advice!

 

[Digit]

I think Karl is reading pony power not horse power. On the OP the 3.7 kw is motor output. The modern tendency is to state the INPUT power.
A 5HP OUTPUT on single phase with a large blade will have quite a long wind up time, the figure I quoted is a reasonable FULL LOAD current draw.
A good quality modern motor of that size might be in the range of 70 percent efficient, so the 3.7 kw is the 70 % figure.

Roy.

 

[big soft moose]

Good grief that thing is a monster - you must have a fairly good sized shop Have you had a word with your electricity supplier about 3ph power? I would suspect that in the long run this could work out cheeper - as Moose says if you buy further 3ph kit you don't have the hassle of converting them.

Miles

in my, admitedly limited, experience electric suppliers are sometimes reluctant to run 3ph into a domestic property , but so long as there is an appropriate line nearby running it into an industrial unit is no problem and costs between £300 and 500 dependening on the distance between line and unit. (note that this is the price for conection to the premises , you also need to factor in another couple of hundred notes to get a sparky to run 3 phase sockets or hard wiring tails inside the building. (the cost above also assumes the supply can be brought accross your or common property - if it has to cross property owned by a third party you then get into paying for wayleaves and such wheich can inflate things quite a bit)

so cost wise bringing in 3ph isnt much different to buying an inverter - but if you intend to buy more 3ph machinery later (and there are a lot of good deals about on bandsaws, drills, planers etc etc ) if you went the inverter route you would need an inverter per machine , whereas with a 3ph supply you only pay for connection once , so that route starts to make more sense.

 

[9fingers]

OK Guys

I'm back - been away overnight taking the Mrs on a treat and in the mean time this thread has popped up.

We are talking 5hp here which is more than virtually any inverter can provide from a SINGLE phase supply. I think there is an Ormron one that will do it.

HOWEVER, This machine has two motors and therefore not suitable to be run from a single inverter as well as all the switchgear and interlocks will be expecting 415volts. Sorting this out sounds like it is beyond the OPs capabilities

SO Best course of action is to get a CONVERTER - such as a Transwave rated around 6hp or more - might find a secondhand one ??.

There should be no need for a rotary so a static one will be fine and also cheaper. UNLESS, you intend to run other 3 phase machines off it later, in which case a rotary one is best. The rating still only needs to be that of the biggest powered machine you have plus a HP say as only one machine is likely to be running at any one time.

However the OP does this, the workshop will need a very good power feed direct from the incoming mains Consumer Unit.

I feel it would be money well spent to get a spark in to advise on the suitability of the supply before spending money on a converter.

I estimate you will want a 40amp supply coming into the shop which is going to need some serious cable especially if you are any distance from the incoming mains.

If the OP needs any clarification then please come back to me.

HTH

Bob

 

[Anonymous]

OK Guys

I'm back - been away overnight taking the Mrs on a treat and in the mean time this thread has popped up.

We are talking 5hp here which is more than virtually any inverter can provide from a SINGLE phase supply. I think there is an Ormron one that will do it.

HOWEVER, This machine has two motors and therefore not suitable to be run from a single inverter as well as all the switchgear and interlocks will be expecting 415volts. Sorting this out sounds like it is beyond the OPs capabilities

SO Best course of action is to get a CONVERTER - such as a Transwave rated around 6hp or more - might find a secondhand one ??.

There should be no need for a rotary so a static one will be fine and also cheaper. UNLESS, you intend to run other 3 phase machines off it later, in which case a rotary one is best. The rating still only needs to be that of the biggest powered machine you have plus a HP say as only one machine is likely to be running at any one time.

However the OP does this, the workshop will need a very good power feed direct from the incoming mains Consumer Unit.

I feel it would be money well spent to get a spark in to advise on the suitability of the supply before spending money on a converter.

I estimate you will want a 40amp supply coming into the shop which is going to need some serious cable especially if you are any distance from the incoming mains.

If the OP needs any clarification then please come back to me.

HTH

Bob

HI Bob

Thank you for your input.

So what do you reckon?? not worth the hassle?

i have a good spark who i can call upon quite easily.

Any chance of finding a couple of options for me convertor wise? Then i know what i am dealing with?

my wife has told me to suggest a support site for the wives who have lost their husbands to this site and woodwork in general.

Many Thanks

Mark

 

[Doug B]

Mark.

I notice your location is Birmingham, Transwave are at 30 Redfern Road, Tyseley. B11 2BH. well worth the price of a phone call, they are very helpful

If you are thinking you might buy more 3 phase gear, i`d definitely give serious thought to the rotary converter Bob has recommended. I didn`t go down this route 12 odd years ago & regret it.

If i had have bought a rotary converter in the first place, this wouldn`t have happened last weekend.
https://www.ukworkshop.co.uk/forums/the- ... 41253.html
As i would have had the necessary power to use it myself, & Jonlar wouldn`t now have the best bandsaw he used.

Doug.

 

[9fingers]

OK Guys

I'm back - been away overnight taking the Mrs on a treat and in the mean time this thread has popped up.

We are talking 5hp here which is more than virtually any inverter can provide from a SINGLE phase supply. I think there is an Ormron one that will do it.

HOWEVER, This machine has two motors and therefore not suitable to be run from a single inverter as well as all the switchgear and interlocks will be expecting 415volts. Sorting this out sounds like it is beyond the OPs capabilities

SO Best course of action is to get a CONVERTER - such as a Transwave rated around 6hp or more - might find a secondhand one ??.

There should be no need for a rotary so a static one will be fine and also cheaper. UNLESS, you intend to run other 3 phase machines off it later, in which case a rotary one is best. The rating still only needs to be that of the biggest powered machine you have plus a HP say as only one machine is likely to be running at any one time.

However the OP does this, the workshop will need a very good power feed direct from the incoming mains Consumer Unit.

I feel it would be money well spent to get a spark in to advise on the suitability of the supply before spending money on a converter.

I estimate you will want a 40amp supply coming into the shop which is going to need some serious cable especially if you are any distance from the incoming mains.

If the OP needs any clarification then please come back to me.

HTH

Bob

HI Bob

Thank you for your input.

So what do you reckon?? not worth the hassle?

i have a good spark who i can call upon quite easily.

Any chance of finding a couple of options for me convertor wise? Then i know what i am dealing with?

my wife has told me to suggest a support site for the wives who have lost their husbands to this site and woodwork in general.

Many Thanks

Mark

How can I judge if it is worth the hassle?

The transwave prices are here
http://www.powercapacitors.co.uk/Power_ ... files/2010 TRANSWAVE Prices (STC-MT-RT).pdf
you will need a 5.5kw unit minimum

£500 static £850 rotary both plus VAT (buy now before the next budget puts VAT up??)

Have you got a decent supply - the best converter can only achieve what the supply will let it.

Read ALL the info here
http://cgi.ebay.co.uk/TRANSWAVE-SINGLE- ... 5ad8b541a8

and get your spark to talk to Transwave. They are superbly helpful and have been making converters for years (they put one in Noahs ark I understand :lol: :lol: )

As for a support group - we are here for the woodies - dunno about the wives - just take them away for overnight stay some where from time to time - works for me!

Bob

 

[Karl]

Karl
Are you absolutely sure of your figures there?

No - i'm talking rubbish (as has been known to happen from time to time).

It is on it's own feed from the main CU. The fuse end is either 20a or 30a cartridge fuse. Can't remember which.

Cheers

Karl

 

[Digit]

(they put one in Noahs ark I understand

Well if he didn't pay for it now's their chance to get it back Bob!

http://www.express.co.uk/posts/view/171 ... een-found-

Roy.

 

[9fingers]

Karl
Are you absolutely sure of your figures there?

No - i'm talking rubbish (as has been known to happen from time to time).

It is on it's own feed from the main CU. The fuse end is either 20a or 30a cartridge fuse. Can't remember which.

Cheers

Karl

I can only think that the slow blo characteristic of your cartridge fuse is the only thing allowing you to run your saw on a 16 amp commando socket.

My 3hp Xcaliber pulls 20amps plus on startup I have it running on a strand of 15amp fusewire in a old fashioned Wylex CU.

I think you must have a 30amp cartridge to get 5 horses running.
Strictly speaking I think the running current could exceed 16amp so really should have a 32amp commando on there - but lets not lose sleep over it.

Bob

 

[Sheik Hans]

Hi
I've been reading this thread and it has made me question the decision i made yesterday when i ordered a single phase motor. I just had to run into the front room (spare one) and check what motor was on my Wadkin Burgess AGS( i told my missus its a coffee table) . I wish i had started reading this a few weeks ago .Thankfully my Wadkin appears to be a toy compared to this monster being discussed.
I've learnt a lot reading this for which i am grateful . This is a tricky subject ,even for those of us who are electricians. three phase stuff is a doddle ,single phase stuff is a doddle but getting one to work off the other is never as straightforward as people think. If i had a euro for every time i ve been asked to do this i would at least €76 by now .