EE series (ex BS series)

EE SERIES
The newest Buchholz relay release for use in oil-immersed power transformers

KEY FEATURES

• Bottom petcock that allows for gas injection testing
• Waterproof (IP65 protection degree)
• Large inspection window
• Suitable for replacing similar existing and old models (BS standards)

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 PRODUCT DESCRIPTION

A Buchholz relay is a type of oil- and gas-actuated protection relay universally used on all oil-immersed transformers with a rating greater than 500 kVA – conservator type. Buchholz relays are used to protect transformers from faults occurring inside the transformer.
Short circuit faults such as inter-turn faults, incipient winding faults and core faults may occur due to overheating, bad connections and ageing. A Buchholz relay will sense such faults and close the alarm circuit. The Buchholz relay functions based on the fact that an electrical fault inside the transformer tank is accompanied by the generation of gas; if the fault is severe enough, it will be accompanied by an oil surge from the tank to the conservator.
The CEDASPE EE series is equipped with a bottom petcock that allows for gas injection testing. During transformer setup, commissioning or maintenance, proper Buchholz relay contacting can be checked by pumping or injecting compressed air from below.
The EE series Buchholz relay is waterproof and features an IP65 protection degree, enabling its usage even in very rainy and wet environments.
The EE series is even equipped with a large graduated window, allowing clear and easy inspection from the outside.
The EE Buchholz relay has been designed so that it can replace both similar old and new models according to British standards.
The EE series is also suitable for use with a RG3.3 gas collecting device that allows gases to be drained from the relay accumulation chamber operating at eye level; RG3.3 also enables gas injection testing.

Relay type*	Inlet diameter	Transformer Oil	Oil flow rate [cm/s]	Connection design	Flange execution	Standard reference	Catalogue
EE1	1"	up to 1000 kg	100±15	Flanged	Square with 4 holes	EN 50216 and Old BS
EE2	2"	from 1000 kg up to 10000 kg			Round with 6 holes
EE3	3"	from 10000 kg up to 50000 kg
Gas collecting device (suitable for EB 50 and EB 79/EB 80)
RG3.2 model
Others
Wiring diagram
EE series - assembly sketch
Gas analyzer for Buchholz Relay
Pneumatic test
* Special design on demand