On load tap changer (OLTC) explode?
Transformer
Vector group: Ynd11
Rated Power: 353MVA
Rated Current: 693A
Voltage:294/20KV
OLTC
Type: T III Y1000 110/c 12193w
Max Operation Current: 295A
Step Voltage: 550V
Arrangement in Tx windings: Y Connection
Problem: Damage of Unit 1 Generator Transformer On Load Tap
Changer (OLTC)
Description of Incident:
9.00 a.m. :- Generator No Load test on excitation system
started
10.30 a.m :- Carried out AVR change over
test
11.30 a.m :- Preparation for Generator Manual Synchronizing
test
12.00 a.m :- Manual Synshronizing test started.
Observed incoming generator voltage higher than running voltage.
CECR operator operated Generator Transformer OLTC to bring down
the incoming generator voltage
12.03 a.m :-Generator Transformer abnormal alarm operated at
Gen.Control Desk (CECR)
CECR operater at Generator transformer bay informed that the
transformer
oil splashed out from OLTC.
CECR operater informed that he heard explosion inside OLTC.
Observed Oil level & Oil Flow alaram operated at Tranformer
local annunciator.
12.05 am :- CECR operator 'Open Gen Field Breaker”
12.10 a.m. :- Elec1 team inspected the OLTC and found the
OLTC rupture disk was broken
and oil spilled at OLTC area.
- Elec1 found the OLTC top cover bulging.
Do anyone know why and possibility cause happen in this OLTC.
Answer Posted / j.ikesavan
my friend please check your inter lock system how to
working motor on load tap changer your winding failure its
going up and down voltage thats why this disc is breake.
| Is This Answer Correct ? | 1 Yes | 4 No |
Post New Answer View All Answers
Why are the laminations insulated from each other?
Can you used moeller lzm1 mccb in a dc system with 125vdc and 20ka short circuit current , beside is it have 24 or 48 volt shunt ? Beside how long current can through from An MCB shunt contacts? (like Z7-AS 24 V)?
I want single line diagram for AMF & DG syncronizing panel
what is the constructional difference between a power transformer and potentian transformer?
why should the lowest unit of a testing transformer ( cascaded transformer ) have higher power rating??
What is the equivalent circuit of a transformer and its vector diagram?
i karmveer bharti persuing b.tech . plz send me syllabus and name of reference books. for preparation of section eng.
Please define ampere?
What happens when ac supply is given as excitation voltage instead of dc supply
How many VSC based HVDC are there in India and the world
I have iti elec, 1st aid, and 5 yrs experience in 7.5 mw power plant. Am i eligeble for 11kv license in telangana state..when, how to apply for that.?
Why is remote backup preferred to local backup?
Give the topology of current amplifier with current shunt feedback?
What is the difference between solid grounding and impedance grounding?
why we can use 1 to 5V dc