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BobL
7th Oct 2016, 10:11 PM
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 (http://www.ebay.com.au/itm/Variable-Speed-Drive-VSD-VFD-1-5-KW-415V-3-phase-in-3-phase-out-/322277782300?hash=item4b0940b31c:g:wpwAAOSwT6pVnfhf)

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 (http://mjbcontrols.com.au/node/43)
133 page manual seems pretty good

Does anyone know anything about them?

MasterSpoon
8th Oct 2016, 10:12 AM
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/files/pdf/SY8600_Variable_Speed_Drive_User_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

BobL
8th Oct 2016, 10:22 AM
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/HuanYang-1500W-1-5KW-2HP-Vector-control-vfd-inverter-Drive-Variable-Frequency-for-spindle-motor-Input/32379146530.html?spm=2114.10010108.1000023.5.H22cPC

jhovel
8th Oct 2016, 06:23 PM
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 .....

BobL
8th Oct 2016, 10:41 PM
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?

jhovel
9th Oct 2016, 02:23 AM
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....

Stustoys
9th Oct 2016, 11:04 AM
Not exactly what you asked but would it be possible to just switch the motor to a resistor bank?

BobL
9th Oct 2016, 11:23 AM
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.

Stustoys
9th Oct 2016, 02:56 PM
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

BobL
9th Oct 2016, 03:33 PM
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.

jhovel
10th Oct 2016, 12:34 AM
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