Hermetically Sealed Transformer

Hi, I am currently working on a project where we are require to purchase 4 units of 1600 kVA hermetically seal transformer. I come to a situation where a few of our vendors are proposing a hermetically seal type transformer that the tank top of the transformer is NOT welded, but instead it is bolted with gasket to prevent oxigen ingress.

Based on my limited experience on transformer, I always understand that hermetically seal transformer shall be welded, including the tank top. This is applicable to our transformer which is purchased 10 years back, where the tank top is welded.

However, these vendor had now reply that the due to the advancement of the gasket technology, they are confident to propose a bolted type. Would like to understand anyone could share their experience on this issue ??

Rgds,
AK

Star Delta Starter - Open Transition Vs Close Transition

Star Delta Starter - Open transition VS Close transition

L & Gs,

In my project I had come across a selection between a close transition and open transition Star Delta Starter.

Having an open transition I will definately benefit from smaller space requirement.

But I would like to know is there any advantage for close transition over open transition ?

Your valuable experience is greatly appreciated.

Rgds,
rome

Motor Starting Study Using Vsd With Skm Powertool

Hi,

I am trying to model the power system in a offshore platform using the SKM software but I am stuck on how to model the motor starting using variable speed drive.

The motor is a 160 kw 415V motor , driving condensate export pump and the VSD is ACS-800.

How can I model the starting characteristic and validate it ?

Appreciate anyone can give me a direction.