ISO 9001 2015 ISO 14001 2015 RƠ LE ÁP SUẤT ĐỘT BIẾN TỔNG CÔNG TY THIẾT BỊ ĐIỆN ĐÔNG ANH – CÔNG TY CỔ PHẦN Địa chỉ Thị trấn Đông Anh – Hà Nội ĐT (84 4) 38833779 – Fax (84 4) 38833113 Email mail@eemc co[.]
Trang 1ISO 9001:2015 ISO 14001:2015
RƠ LE ÁP SUẤT ĐỘT BIẾN
TỔNG CÔNG TY THIẾT BỊ ĐIỆN ĐÔNG ANH – CÔNG TY CỔ PHẦN
Địa chỉ: Thị trấn Đông Anh – Hà Nội ĐT: (84.4) 38833779 – Fax: (84.4) 38833113
Email: mail@eemc.com.vn * Website: www.eemc.com.vn
Trang 3INSTRUCTION MANUAL
SUDDEN OIL PRESSURE RELAY TYPE PVOAY2 2
(2 contact )
HYODA INSTRUMENTS CORPORATION
Trang 4reactors shall be provided with safety device that is securely protect an equipment from potential damage caused by internal faults
1 Features
(1) If an accident occurs in a equipment, this relay quickly responds
to fluctuations in the internal pressure and works even if a pressure difference is slight
Therefore the time between the occurrence of an accident and
shutdown can be extremely shortened
(2) Since this relay is mainly to be installed the tank side of a
transformer
(3) This relay uses microswitch for the electric contact, which ensures switching and high reliability
2 Structure
The structure of this relay is shown in Fig 1 As shown in the figure,
The body is made of aluminum alloy casting which provides high air
tightness The internal section is composed of a movement bellows,
pressurereceiving bellows, orifie(equalizer) and micrositch The switch terminal is to be taken out of the upper terminal box
3 Operation
When the internal pressure of the transformer tank rises rapidly due to
an accident in the transformer, the hydraulic pressure compresses the pressurereceiving bellows, which pushes UP the movement bellows
The motion of the top of the movement bellows pushes in the microswitch lever activating the contact
If hydraulic pressure fluctuation in the transformer are negligible, the microswitch will not be activated regardless of the numerical value of the pressure
Due to the capacity limit in the bellows, if the normal pressure at the Installation position exceed 0.027MPa (about 3m of oil head), this Relay may not operate properly
Trang 52
Fig.1 SUDDEN OIL PRESSURE RELAY
1 Cover
2 Equalizer
3 Movement bellows
4 Case
5 Operation check shaft
6 Operation check cap
7 Pressurereceiving bellows
8 Microswitch
9 Name plate
10 Rellef plug
Trang 6represents the value of pressure increase in the transformer tank: the x axis represents the time between the occurrence of pressure increase and the activation of the microswitch The diagonal broken line in the figure indicates the rate of pressure increase in the transformer The intersection of the broken line and the curve thick line indicates the corresponding operation time
Minimum operating pressure difference: 0.025+30% (MPa)
Minimum operating pressure increase rate: 0.005+40% (MPa/ sec)
As this evident from the operating characteristics shown in Fig.2, this
Relay instantly responds to such a rapid pressure increase as expected
in the case of an accident in a transformer: the higher the rate of
pressure increase is, the quicker the operating time becomes
Fig.2 Operating characteristic curve of Impact Hydraulc Relay
Type: PVOAY22
Trang 74
5 Contact operation check
(1) Keep a value open it a valve is provided in between the Relay and the transformer tank
(2) Disconnect an auxiliary Relay circuit from the Relay Connect a test
light circuit
(3) Dismount the cap of the inspection shaft that is attached under the
Relay housing
(4) Quick push the inspection shaft brim by hand
So that the pressurereceiving bellows is pushed up and actuate a
switch
(5) After the test is carried out, the cap of inspection shaft should be
screwed original oosition
6 Handling caution
(1) If the Relay is given a shock during transportation, its function could
be deteriorated For the transportation, remove the Relay from the
transformer and transport it separately
(2) This Relay is mounted on the transformer tank side wall in between
0.5~3meter below an oil top level, using a butterfly valve, etc
whose opening area should be as large as possible
(3) After the Relay is properly mounted the air vent (fig,1 number 10)
should be opened to allow a little of an oil to flow out Then, close the
air vent