Thread: 3p -3p 2hp vfd

The men's shed has a 3P Nolex 12" RAS which takes around 3 minutes to come to a stop when turned off. During this time it is very quiet and in the general hum-drum of shed activities it is impossible to hear that it is still running.

I have looked at fitting a mechanical brake but there is nowhere to get any mechanical purchase so I though a VFD might be the way to.

The motor is 415V ∆ and to save stuffing around with the motor I though a 415-415V 3P VFD with a built in braking circuit would be the way to go.
I have looked around and these $215 senseless Vector drive units have come up on eBay.

Variable Speed Drive VSD VFD 1 5 KW 415V 3 Phase IN 3 Phase OUT | eBay

They have a AUS presence

MJB Controls Pty Ltd

Unit 25/205-213 Port Hacking Rd Miranda NSW Australia 2228

Variable Frequency Drives / Variable Speed Drives | MJB Controls
133 page manual seems pretty good

Does anyone know anything about them?

Can't speak specifically about that one Bob but don't all VFD's have the ability to brake the motors these days ?

Looking at the manual for that one
http://mjbcontrols.com.au/sites/file...ser_Manual.pdf
Pg 62 PDF / Pg number 59 - P0-17 Dec Time 1
- this should be for setting the time
Pg 64 PDF / Pg number 61 - P1-05 Stop mode selection
- this should set the braking mode

Originally Posted by MasterSpoon

Can't speak specifically about that one Bob but don't all VFD's have the ability to brake the motors these days ?

Well yes and no, some have the beginnings of a braking system but have some chip missing from the boards. Jhovel has successfully added the chips to some of his SP-3P Huanyangs but I was hoping to avoid doing that. Maybe the 3P-3P Huanyangs already have the braking chips in them but the manual doesn't indicate this one way or the other.

I have also found the GT series Huanyangs are Vector control, 3P-3P, and according to the manual have a built inbraking circuit.

GT series inverters <15kW (380V) are equipped with internal braking unit.Inorder to dissipate the regenerative energy generated by dynamic braking, thebraking resistor should be installed at (+) and PR terminals.

Although I can't see any "+" terminal on the photos provided.
Pricing seems reasonable
eg https://www.aliexpress.com/item/Huan...00023.5.H22cPC

Bob,
I can see the P+ terminal next to the PR connector in the bottom row. Same as the single phase Huanyangs. Their manual proudly states they have a built-in braking circuit .....

Originally Posted by jhovel

Bob,
I can see the P+ terminal next to the PR connector in the bottom row. Same as the single phase Huanyangs. Their manual proudly states they have a built-in braking circuit .....

so "P+" = "+" ? - Maybe I was looking too hard?

Is that where you have your external resistor connected?

Yes, it is Bob. Some single phase manuals call them PR and N, P and N, another one PR and +..... the actual labels on all mine are PR and P+
go figure....

Not exactly what you asked but would it be possible to just switch the motor to a resistor bank?

Originally Posted by Stustoys

Not exactly what you asked but would it be possible to just switch the motor to a resistor bank?

I assume you mean turn of VFD, disconnect VFD from motor, connect motor to resistor bank. If that was not done it could end up sending a bolt of emf back into the VFD.
That's why its better to let the VFD do all the switching as it does it a lot faster and safer than any manual operation.

Hi Bob,

No. It appeared to me the mens shed has 3P and the only reason you where using a VSD in this case was to get braking. If that's the case, couldn't you forget the VSD and just switch the motor from mains to a resistor bank. Wouldnt be as good as the VSD braking because there will be no DC, But you should be able to shorten 3 minutes considerably.
It would be more mucking about to set up than the VSD but may work out cheaper and maybe even more reliable?

Stuart

Originally Posted by Stustoys

It would be more mucking about to set up than the VSD but may work out cheaper and maybe even more reliable?
Stuart

They have the funds so they can afford a VFD. I just wanted a quickish solution.

Hi Stu,
that's how they used to do it in the old days. The bigger the resistor (and lower the resistance) the better it worked. I've seen old machines with a rotary change over switch that did just that: Run - OFF - BREAK/STOP