A hardworking student who love to guide others!!

1. Submitted by:- Bhavesh Manghnani(16EE50)
Submitted to:- MR. DEV PRATAP MAHTO
Topic:-BUCHHOLZ RELAY

2.  INTRODUCTION
 BASIC CONSTRUCTION
 OPERATION
 Types of fault
 ADVANTAGES
 DISADVANTGES

3.  Buchholz relay is a type of oil and gas actuated
protection relay universally used on all oil immersed
transformers having rating more than 500 kVA.
 Buchholz relay located between the conservator tank
and main tank of transformer. Which energised an
alarm circuit and trip circuit during transformer faulty
condition.

7. Minor Internal Faults
 Insulation faults between turns.
 Breakdown of core of transformer.
 Core heating.
Major or Severe Faults
 Short circuit between phases.
 Short circuit between phases to earth.
 Fault in tap changing equipment.

10. Advantages of Buchholz relay
 Buchholz relay indicates inter turn faults and
faults due to heating of core and helps in the
avoidance of severe faults.
 Nature and severity of fault can be determined
without dismantling the transformer by testing the
air samples.
Limitation of Buchholz relay
 It can sense the faults occurring below the oil level
only. The relay is slow and has a minimum
operating range of 0.1second and an average
operating range of 0.2 seconds.

11. THANKYOU!!