[chbot] VFD with Chocolate fish.

Mark Atherton markaren1 at xtra.co.nz
Wed Jun 30 08:08:20 BST 2021

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.


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

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