Proud to be an Electrical technician

02/06/2022

Nitrogen Injection Fire Protection System commissioning

02/04/2022

11/12/2021

Nyakanazi substation

10/12/2021

40 Mva transformer assembly

28/09/2016

A weak point on 132kv cable after energizing this is the result

20/03/2016

Transformer loss angle test using Tan delta test equipment

12/03/2016

132kv cable joints

17/02/2016

HV termination preparation

31/12/2015

BUCHOLZ relay functional on tranformer

It is a gas operated relay.It is placed between Main Tank & Conservator Tank,with an angle5-7 Degree.There are2 Mercury switches, one in the top & other in the bottom of Bucholz relay,filled with Transformer Oil. When small amount of vapour passes through the relay Top Float will operate, gives Bucholz alarm.In case of heavy internal fault, Large amount of Bubbles forms,operates the Bottom Float , Gives Bucholz Trip.In case of Bucholz Alarm/Trip Relay contact to checked first(IN Alarm/Trip Relay contact will change).then if there was any gas formation occured.Gas should be relaesed through the top Vent of relay( in that time hissing sound is observed in case of Gas present).Have to release all other top vent in Main Tank & Radiator Top.
In case of OLTC, there are saperare OLTC Surge Relay, same as Main tank Bucholz Relay.
After gas release if Trafo again tripped in Bucholz.Then there must be some hot spot/heavy internal fault in Trafo.other necessory testing to be carried out, like Ratio test,Magnetic Balance test,Vector group test,IR Test for further fault finding.

08/07/2015