VFD or replacement for 3-phase motor for Jointer

[ajones]

yes it can if the vfd output matches that of the motor. connected in delta I would expect the motor to be 230/240 v look at the data plate on the motor

 

[Mrjackg]

yes it can if the vfd output matches that of the motor. connected in delta I would expect the motor to be 230/240 v look at the data plate on the motor

Attached is the data plate .. No mention of 240v... Also not sure if gs1 would run this?

 

[ajones]

the data plate shows Y and 415v which is the same as star, you can see the motor can be wired in delta, and what you do when you do this is half the length of the coils hence it will then run on 240v

So I cant see any reason why it would not run happily on 240v. I would use a capacitor for the 2nd leg and spin it up in the first instance..

this is all very basic stuff but... I am not an electrician

 

[Rick Christopherson]

Yes, if you can configure the internal motor wiring for a Delta, it should be operating at 415/sqrt_3 = 240.

If you look at the diagram below, each of the windings (the straight lines) always sees 240 volts regardless how it is configured. In the wye configuration, 2 windings are seeing the total of 415, but each one separately still sees only 240. (The squareroot of 3 term is due to the phase angle between them. That's the meaning of the notation at the bottom "voltage ratio 1.732 to 1")

Yes, the GS1 would run this motor just fine in this low voltage configuration. By the way, regardless how a motor is internally configured, it is always connected to the power source with a delta connection. Some people mistakenly think the terms wye/delta for motors applies to the incoming power. It doesn't. Incoming power to a motor is always delta.

Edit: Oh, care should be taken at this point to ensure that this is not simply set up as a single voltage, wye-start, delta-run motor. If that is the case, the windings are actually designed for the 415 volts, and when in the wye configuration for startup, they are getting less than their rated voltage to keep the inrush current low. If the motor is already in the delta configuration, then it is not dual voltage 415/240. It is wye-start/delta-run, and cannot be connected to 240 volts.

 

[Rick Christopherson]

I did a search for your Trojan model number. It appears that this is a dual voltage 240/415 motor. That is also supported by the nameplate, where it says "CONN Y".

Trojan 1.1MD1A80B-2B3

 

[Mrjackg]

Great news, yes i saw that in the name plate I
And thought that could mean that.  Yes it's currently in y or star, so this should be good to go when re wired into delta.  Great thanks for your help!

 

[Mrjackg]

So to change the Trojan motor to Delta all I need do is move the copper links as shown in the terminal box cover?

I called the company I bought the GS1 from and they suggested that I could use in on the the other motor (star 415v single voltage), but it would be only running it at half the power, is this accurate?

 

[ajones]

Yep move the jumpers as shown on the lid,there should be three jumpers in there, if you can put some crimped terminals  on the ends of the power cables.

if it revolves the wrong way swop two incoming legs does not matter which two.

and do NOT connect both ends of the same coil together ie; u1 to u2...

u1 should connect to w2 or v2 and so on. as in Icks drawing

another important point,do not run the motor at low speeds as the fan that cools the motor does not do its job,motors run at low speeds need forced cooling

 

[Mrjackg]

Hi, just thought Id let you know that I got the GS1 VFD working!  I rewired the (Drill Press) Crompton Parkinson motor with advice from Jim over at Practical Machinist see the thread here if interested.

I tested both motors on the GS1 and all works perfectly!  Thanks for your help!

 

[ajones]

Hi, just thought Id let you know that I got the GS1 VFD working!  I rewired the (Drill Press) Crompton Parkinson motor with advice from Jim over at Practical Machinist see the thread here if interested.

I tested both motors on the GS1 and all works perfectly!  Thanks for your help!

I find the fact that you can rewire for delta internally interesting,while it is logical i would not have thought to do it, if I was in that situation..

well done on not frying yourself or the motor [wink]

 

[Mrjackg]

Others have done this method Here and Here so I figured I'd give it a go and it worked. [tongue]