Wiring Brook Crompton 3 phase motor to Delta.

[raynerd]

Hi guys, I`m trying to re-wire my 3 phase Brook Crompton motor to delta. I`ve taken the cover off the back and the first thing that hit me was the fact that it classes the two wiring types as Star and Mesh....I take it Mesh is Delta?   I`m confident I can follow the layout, I just wanted to confirm that mesh is Delta?

[John Stevenson]

Yup.

You have it right.

John S.

[raynerd]

Cheers John, I do google it but didn`t come up with anything. I thought it must be right so thanks for confirming.

How tricky are the inverters to wire up? - obviously I guess I`ll find out when it arrives!

Chris

[DMIOM]

......How tricky are the inverters to wire up? ......

Physical wiring is easy - just three suitably insulated cores (ideally of equal length) plus really good earth.

Also, if your inverter provides it, make use of their E-Stop.

You do need to be careful, especially when doing the initial wiring, to remember that the capacitors in the inverter can hold their charge for a wee while after the incoming mains power is removed.

Depending on what inverter you've bought, you've then got some setup to do (the ABB ones I use have hordes of parameters!) but many are adaptive and will learn the motor's inductance etc. on their first run.

Key things to watch out for though are setting the min & max speeds for your motor.  Max speed for the bearings etc. , min speed for cooling.  Many motors have a fan on the end of the shaft, sized to provide sufficient cooling when running at normal mains frequency, but if you run too slow there may not be sufficient airflow.

The inverter itself will need some airflow and possibly forced cooling if its in an additional enclosure.

There's also a chance that the hash from the actual inverter appears on nearby mains and you may just find you need extra filtering (either on the inverter, which can be expensive) or just as a suppressor on the affected computer etc.

Dave

[raynerd]

Thanks for the advice.

The inverter and controller are shown below.

Jaguar VXS Inverter.(0.75KW/1HP). Good Used condition, set up ready to go with 2 Sec soft start & stop, Forward, reverse & Jog and variable speed control. Complete with programming module & manual on CdRom. 230V single phase in, 230V 3 phase out for delta connected 3 phase motor up to 1HP. Ideal for lathe/Drill/Mill. with free remote control box kit

He did mention that the inverter is "ready to run" and that most of the parameters have been set. I guess I`ll find out how easy it is to hook up when it arrives!

[John Stevenson]

If this is one of Gavins inverters you should be set to go out of the box.

If not shout up, we used to build inkmixers with these inverters fitted and have literally fitted 100's

They do have 7 pages of parameter settings but only a few are needed.

Main thing to check and I'll dig the book out tonight is that you will have to set the Kw of your motor so the overload / safety trips in at the right point.

[DMIOM]

..... He did mention that the inverter is "ready to run" and that most of the parameters have been set.....

OK, those'll be the parameters for the pendant, and his motor/machine.  You'll need to review them for your motor/machine.

If the "Stop"s are all set for 2 sec run-down, then you may want to check if there is a more expeditious E-Stop input -  a 2 sec slowdown is reasonable for a planned stop, especially on, say, a mill - but an awful lot of mischief can happen on a lathe in 2 seconds ....

Jaguar VXS Inverter.(0.75KW/1HP). Good Used condition, set up ready to go with 2 Sec soft start & stop, Forward, reverse & Jog and variable speed control. Complete with programming module & manual on CdRom. 230V single phase in, 230V 3 phase out for delta connected 3 phase motor up to 1HP. Ideal for lathe/Drill/Mill. with free remote control box kit

Have used Jaguar cub inverters before & they're good kit.  The advert mentions its for a 230v three-phase motor - I don't recall seeing a plate illustrated for your 3 phase Brook Crompton motor - it is one that'll operate on 230v 3 phase isn't it? ......

[raynerd]

Cheers John. Yes, it is one of Gavins - it was a good price and nice bloke to deal with so far.

Question for you - what does the jog button do to the motor?? Sound like it is going to move it in one direction but isn`t this the same as the "on" button? Or does the ON just turn on the inverter and power up?

Chris

[raynerd]

The advert mentions its for a 230v three-phase motor - I don't recall seeing a plate illustrated for your 3 phase Brook Crompton motor - it is one that'll operate on 230v 3 phase isn't it? ......

I take it the 220/250v means it`ll work on 230v ??

[John Stevenson]

If the "Stop"s are all set for 2 sec run-down, then you may want to check if there is a more expeditious E-Stop input -  a 2 sec slowdown is reasonable for a planned stop, especially on, say, a mill - but an awful lot of mischief can happen on a lathe in 2 seconds ....

[ The advert mentions its for a 230v three-phase motor - I don't recall seeing a plate illustrated for your 3 phase Brook Crompton motor - it is one that'll operate on 230v 3 phase isn't it? ......

Yes Craynard's motor will be 230 v three phase in delta as it uses two coils per phase,
2 seconds will be fine, remember you don't have any control over normal motors, it's down to the load  / speed that determine the spool down time.

Most people make the mistake of having these things stop dead because they can. It causes untold damage to mechanical components like keyways etc and worst case can unscrew a chuck.
Dropping below 1 second without the optional braking module often throws up error messages causing you to have to reset the inverter.
Sticking at about 2 seconds cures all this and gives faultless running.

[John Stevenson]

Missed the query about jog.

Jog is normally programmed to a lower frequency like 10 Kh so when held it rotates at a lower speed, ideal for clocking up etc. I think the VXS has 15 preset speeds [ rusty memory ] so you can use it with 15 switches like a manual gearbox.

[raynerd]

That sounds great! I think and hope this is going to be a worth while mod to make to this lathe.

When you say:

I think the VXS has 15 preset speeds [ rusty memory ] so you can use it with 15 switches like a manual gearbox.

Do you mean physical switches...so you can literally have 15 preset speeds along with the variable speed pot on the pendant?

Thanks for all the info.
Chris

[John Stevenson]

Not both,
variable or presets.

[raynerd]

If this is one of Gavins inverters you should be set to go out of the box.

If not shout up, we used to build inkmixers with these inverters fitted and have literally fitted 100's

Here I am shouting out !!!! 

It has just arrived and I can say it doesn`t seem quite as ready to run as I expected!! Perhaps I was nieve but I just expected a little diagram of which wires to connect to the motor and off I went. Sadly, the pendant isn`t even built and is in bits so you have to build that yourself! It has only been with me 20 minutes, but at present I can`t see where or what to connect to the motor and the more concerning bit is that I can`t find where anything should be plugging into the mains to power it all 

I`m sure I`ll be fine when I sit down with it later on and take a proper look but first impressions are concerning me. 

I`ll post some pics and more info of exactly what I have in the box later. And by the way, certainly not criticising the sale, OK I expected the pendant to be built but the inverter looks in mint condition and is cheaper than anywhere else I have seen them!

Chris

[raynerd]

Just so I don`t look too much of a dumb a!s3, I`ve not taking the top of the inverter yet and from the little reading I have done, it mentions a "high voltage rail of the inverter" so I take it there is a live, neutral and gnd for the power connection in there?!

[raynerd]

OK thanks for the help on here. This will soon be going on the Boxford so to keep it all together I`m going to start posting further info regarding this motor on the Boxford thread...

http://madmodder.net/index.php?topic=1231.msg36932#new

Thanks again!