[chbot] VFD with Chocolate fish.

Mark Atherton markaren1 at xtra.co.nz
Wed Jun 30 08:13:33 BST 2021


Have you checked continuity between mains in and the bridge rectifier 
using a meter, or just by inspection ?

Not sure of the rating of the unit you have purchased, but I might also 
expect some kind of power-factor correction before the main reservoir 
caps. Are you 100% sure that the input terminals don't dive off around 
somewhere and then back to the caps ?


On 30/06/2021 7:08 PM, Mark Atherton wrote:
> Sounds like the factory modified the product (wrongly) then shipped it 
> without testing it.
> Three phase inputs (L1, L2, L3) should go the the bridge rectifier via 
> R, S & T.
> I have a couple of 3 ph VSDs that don't trip with under voltage if you 
> use single phase, and attach phase to L1, and neutral to L2.
> Before you go any further, what is the voltage rating of the reservoir 
> cap(s) directly after the bridge rectifier ?
> I would expect at least 385V caps for the 240V model and 620V caps (can 
> you get these ?) for the 3 ph 415V variant.
> -mark
> On 30/06/2021 6:04 PM, Marshland Engineering wrote:
>> I'm stumped with a VFD from Aliexpress. Here it is
>> https://www.aliexpress.com/item/1005002038502819.htm
>> Nothing turn on with power. As a true engineer, off came the cover. 
>> Now I'm
>> either blind, missing something  completely or its a faulty design.
>> It has a 3 phase rectifier in it, + and - go to the HV caps. One of the 3
>> phase input leads is cut off. Looks like a factory job. The other 2 input
>> leads are soldered together on the PCB and go to the input live 
>> terminal. I
>> cannot find any connection on the PCB from the neutral terminal. 
>> Stumped. Now
>> I did get a complete new PCB when I discovered they sent me a 240V out 
>> instead
>> of 380V one . It is exactly the same.
>> Anyone got a few minutes free tomorrow ? I come loaded with chocolate 
>> fish or
>> similar.
>> Cheers Wallace
>> 03 3237449

More information about the Chchrobotics mailing list