Cost to convert to 3 phase

[MusicMan]

I use 240-415 VFDs from Drives Direct on three machines (lathe, miller and saw, two 2kW and one 1kW I think). The variable speed facility is in regular use on the lathe, occasionally on the miller and never on the saw. But on the saw I've programmed the software deceleration so that even this old Wadkin saw will be brought to a stop in 8 seconds. This is a very useful feature of the programmable drives.

They are not cheap, £350-£450 (my motors were not easily rewirable), but do the job brilliantly and have worked flawlessly for some years now. Too small for your big machines though.

 

[Random Orbital Bob]

My problem is this is for a 7.5HP industrial strength spindle moulder running tooling capable of cutting long tenons and it will need a fair bit of power I suspect so if it's the inverter route then it has to be able to cope. On the other hand, there's no way I'm going to be spending n thousands on having a Utility poke red hot needles down my trousers!

 

[Farmer Giles]

its a pity your so far away Bob, you could have brought your spindle moulder around and tried it on my 10hp inverter to see how you like it before buying, however even if your close I guess they are not that portable

Direct Drives are a small family company and I believe they used to sell rotary inverters before moving over to VFD and PWM inverters, I would give them a call and ask their opinion.

 

[graduate_owner]

Random Orbit Bob - a friend has a colchester mascot ( maybe mastiff) which has a 7.5 HP motor, and he runs it from a transwave rotary converter with no issues. No variable speed, being a converter, but uses original switchgear. This could be the solution for you. Not chap though, £1200.

K

Edit - you would need a 10HP version to run a 7.5 HP motor, because of the starting current - £1500

 

[deema]

That's a big spindle moulder with an awful lot of power! You will be able to take some awesome cuts with that.

A 5.5Kw inverter will cost c£450 if you shop around and go for a decent make . I'd definitely run something that size off an inverter if your going down the 1ph route. Soft start and the ability to add a breaking resistor to make it if it's not already compliant for stopping time are big advantages. I would add filters to the inverter for domestic use to prevent interrupting the neighbours tv/ internet/ gaming or what ever afflictions!!

 

[graduate_owner]

That price sounds very reasonable to me. I am glad I went down the inverter route, even if just for variable speed.

K

 

[RogerS]

.......


Cheers
Andy

50 Amps at full load :shock:

My incoming 1/4 mile 240v "extension" cable would die. Sightly OT but I enquired the cost from Northern Power of running in a proper 11kv supply to a new transformer at our property. Estimates were £35k overhead and £66k underground. Decided to pass.

 

[Doug B]

That's a big spindle moulder with an awful lot of power! You will be able to take some awesome cuts with that.

A 5.5Kw inverter will cost c£450 if you shop around and go for a decent make . I'd definitely run something that size off an inverter if your going down the 1ph route. Soft start and the ability to add a breaking resistor to make it if it's not already compliant for stopping time are big advantages. I would add filters to the inverter for domestic use to prevent interrupting the neighbours tv/ internet/ gaming or what ever afflictions!!

+1

I've 3 inverters & they were still way cheaper than getting 3 phase installed, as Deema says on a big machine the extra features an inverter gives you over just providing 3 phase are excellent, I have one on a big old Wadkin planer which I initially converted from 3 to single phase by changing the motor, but the amp draw on start up would dim the lights due to the size of block the motor was trying to get spinning, with the motors swapped back it's now programmed through the inverter to be up to speed in 8 seconds & to stop in 9 & works like a dream.

The only draw back I've found is I can't have the inverters powered up at the same time as that trips the RCD that feeds the workshop, not a biggie for me as they are on machines that don't work in conjunction with each other, worth knowing if you were going to run a machine & dust extractor both off inverters, then again I guess you could do away with the RCD.

 

[wallace]

My spindle moulder is a wadkin EQ and 6hp it can run at 9k rpm. My 5.5kw static starts and runs this no problem

 

[Random Orbital Bob]

That's all very encouraging chaps, thanks for the input. Most appreciated.

 

[Claud1]

I had a Transwave converter for a couple of years and then decided to have 3 phase installed it is the best 6k I have spent in the workshop and now almost everything is three phase The converter was ok but it was noisy and nowhere near as powerful as three phase. all down to cost and personal choice at the end of the day