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Echo-Star

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Evening all

I would like to ask for some help/put me on the right track for cable EG from mains to VFD and VFD to 3kw motor, and would this have to be 16A
I've been looking at this from VFD to motor, though not sure if adequate RS PRO 4 Core 1.5 mm² Power Cable, Grey Polyvinyl Chloride ...


I also have a 2nd 3ph 3kw motor to be powered, Q:- Can both machines be wired/programmed to the same VFD

I'd much appreciate any help here thank you

Rob
 

Sideways

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Read previous posts. These issues have been covered plenty of times and most will be answered if you have a half decent VFD and just read (all 20 / 35 / 76 / whatever pages of) the manual.

No you can't properly / safely run two motors from the same VFD together or without appropriate reprogramming in between.

For the mains to VFD supply cable, follow the manual and use something 3 or 4 core, stranded and correctly sized to the supply fuse and that should be chosen to satisfy the VFD maximum demand.. Your manual will probably tell you that 16A single phase is too small for a 3kW VFD.

For the VFD to motor cable, use "SY" flexible cable with a protective wire braid, spec and size again according to the manual based on the maximum rating of the VFD, not the rating of the motor

You are asking basic questions. Configuring a VFD properly is more complex. Ask yourself if you have the knowledge and skills to be doing this.
I suggest you get help from someone qualified. You can't sue the internet if you burn your house down because you failed to understand something or you overlooked a line in the manual and gave yourself a lethal jolt.
 

deema

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I would look at getting a digital phase converter. It will allow you to run multiple machines. You would get one, install it and plug any 3 phase machine into it without modification. Doesn’t need to be dual voltage as they produce proper 415v 3 phase. They are the cheapest and most flexible solution for multiple machines. They can run multiple machines all at the same time, so one Phase Converter, the right size can run your shop. If your running just one machine, they can provide speed control etc just like a VFD.
When I supply them, i usually wire them up with a socket so that apart from connecting them into the consumer unit / distribution board they are good to go. It’s an option that works well for anyone not familiar with electrics.
 
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Echo-Star

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Hi deema

I seen your reply to my post, and I've been meaning to get some pic's off the motor plates for you, though I cant get access to 2 of them due to a restoration I'm doing and don't have the room to move stuff around. I have 2x 3kw and 1 x 1.5kw all 3ph the 1.5 has had the winding rewired for Delta 230v as only had 3 wires coming from the motor. I have looked into getting a "Digital Phased Converter" and I would think the right thing for me though at £700+ is a little out off my price range at this time.

Although that is not to say I may get one.

Regards Rob
 

Echo-Star

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Read previous posts. These issues have been covered plenty of times and most will be answered if you have a half decent VFD and just read (all 20 / 35 / 76 / whatever pages of) the manual.

No you can't properly / safely run two motors from the same VFD together or without appropriate reprogramming in between.

For the mains to VFD supply cable, follow the manual and use something 3 or 4 core, stranded and correctly sized to the supply fuse and that should be chosen to satisfy the VFD maximum demand.. Your manual will probably tell you that 16A single phase is too small for a 3kW VFD.

For the VFD to motor cable, use "SY" flexible cable with a protective wire braid, spec and size again according to the manual based on the maximum rating of the VFD, not the rating of the motor

You are asking basic questions. Configuring a VFD properly is more complex. Ask yourself if you have the knowledge and skills to be doing this.
I suggest you get help from someone qualified. You can't sue the internet if you burn your house down because you failed to understand something or you overlooked a line in the manual and gave yourself a lethal jolt.
Hi Sideways

I have been looking at all options open to me at this time, I have #2 x 3ph machines at the moment, and will possibly be adding a 3rd. I have been leaning towards the "rotary phase converter" this could be 5.5kw wired from a dedicated 32A MCB which is about max I believe for the 32a I have for machinery, then it would just be a case off swapping leads over. Cost is a factor "without compromising electrical safety" If I was to go the VFD route, then it would be x #3 at between 2 & £300 a pop. I could only ever have two motors running at anyone time, and extraction being one of them could possibly overload the 5.5 RPC as the TS is 3.3kw on its own. I have 10mm2 SWA running from my cu in house to a 40a unit in ws. So the most appropriate solution for the amperage that is available to me is the advise that I was hoping for. Digital phase is just to expensive for me.

Thank you
 

deema

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A RPC is nosey and not very efficient. You lose power in the motor. Some are genuine 415 and others are 220v 3ph. A 5.5Kw digital Phase converter is £650 delivered and a 7.5kw is £900 delivered. The larger unit is the biggest you can run off your 32A outlet, and will allow you to run everything you will have with no messing about converting the machines to delta / altering the switch gear.
 
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Spectric

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They can run multiple machines all at the same time, so one Phase Converter, the right size can run your shop. If your running just one machine, they can provide speed control etc just like a VFD.
Interested in what ones you are using because I have not come across phase convertors that provide a variable speed, only invertors and we now use more invertors with 400V three phase setup to use the motor configured as Delta. The invertor provides 230V at 50 Hz and then 400V at 87Hz which gives a constant torque upto 87Hz and 1.7 times more power from the same sized motor.
 

deema

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They are made by theses guys

You can also buy them on eBay from Jason, item no 233786567528. I have no connection to this business, other than being an occasional customer.
They have an excellent manual, and although Chinese, it’s a full circa 165 pages written in correct English, and covers everything.

If your looking to have multiple machines that could be 3 phase, then a DFC is a good solution. You can get a profession electrician to install a unit, and then run a 3 phase socket(s) so you simply plug any / multiple machines in to it without any further worries of electrical stuff. The DFC can be located anywhere in the workshop, and preferably away from the dust. Your free then to buy any machine you want, within reason and just plug it in and nit worry about motors, motor starters of VFDs for every machine. For a single machine a VFD or converting it to single phase is the better solution.
I have them up to 15KW, which are big enough to power probably just about anything in a home / small professional shop.

You need to be careful overdriving a motor, cooling is unlikely to be adequate that could lead to infant mortality of the unit.
 
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