FLN36 Indoor SF6 Load Switch

Selection

Operating conditions

1. Air temperature Maximum temperature: +40℃; Minimum temperature:-35℃.
2. Humidity Monthly average humidity 95%; Daily average humidity 90%.
3. Altitude above sea level Maximum installation altitude: 2500m.
4. Ambient air not apparently polluted by corrosive and flammable gas, vapor etc.
5. No frequent violent shake.

Technical data

Primary circuit loop of load break switch

Primary loop of FLN36indoor load break switch and its combination is sealed in a epikote casted insulate unit by APG
technology, this insulate unit has features of good insulating property, dust and dirts proof, insulate unit contains upper and lower insulate covers, inside charged 0.4bars pressure SF6 gas, the partial siding of lower cover is very thin, it’s a protective measure and will burst out in the malfunction, the over pressed gas is released to protect the equipment. ***SF6 load break switch and its fuse combination has open,close and earth three working position.

Arc extinction

FLN36-□D load break switch adopts SF6 gas as the medium of arc extinction, when switch on and off, arc occurs and will spin under the magnetic field effect ion by the permanent magnet, cooled by the SF6 gas and extricated finally.
This indoor SF6 load break switch and its fuse combination works with spring type operating mechanisms A and K,FLN36 load break switch equipped with the K spring operating mechanism is applied as the incoming control unit, while that equipped with A mechanism is applied as the outgoing protective unit and transformer unit.

1. “K” Type Spring Operating Mechanism
Working principle of K type spring operating mechanism is spring press and release (see fig 1. it’s in off position)
A) Earthing operation
Driven by the handle, the upper crank arm 4 rotates and compresses the spring 2 to store energy. When the maximum energy is reached, the crank arm continues to rotate, and the energy storage spring begins to release energy to drive the upper trigger, causing the connecting rod to drive the crank arm. The rotation of the crank arm drives the moving contact for earthing.
B) Switch on operation
Driven by the handle, the lower crank arm 1 rotates, the spring 2 is pressed to store energy, and when the energy is released, the trigger 8 is driven to make the connecting rod drive the crank arm, the crank arm rotates, drives the mobile contactor, and the load break switch is turned on.
C) Switch off operation
Rotate the main shaft crank arm counterclockwise by the handle, release the energy storage spring and the load break switch is turned off.
2. “A” Type Spring Mechanism
Working principle of A type mechanism is same as K type, in addition, it has fuse striker trip function. For A type mechanism, electromagnetic trip is also available on customers requirement.(see fig 2)
A) Switch on operation
Driven by the handle, lower crank arm 1 rotates to presse switch on spring 12 and switch off spring 8 at the same time, to provide sufficient energy required by switching off. when the lower crank arm 1 buckles the pin and drives trigger to move, it makes the lower roller wheel tripd, and release the switch on spring and load break switch is turned on.
B) Switch off operation
Press the switch off button or push the trip pin 2 by the fuse striker, release the spring and load switch is turned off .
C) Earthing operation
Earthing operation of A type mechanism is same as that of K type.
3. K type and A type operating mechanism can be operated manually or motorized on request.
Notice: only when the load break is turned off, can on and earthing operation be done.

Operating mechanism & Interlock

Mechanism Interlock
RLS-24D indoor type medium voltage SF6 load break switch and its fuse combination has below interlocks:
A) When load break switch turns on, earthing operation can’t be done
B) When earthing switch turns on, load break switch turns on/off operation can’t be done
C) Interlock outlet of mishandling pretension is equipped

Overall and mounting dimensions(mm)

Matching dimension of SF6 load break switch-fuse combination
Fig 1) SF6 load break switch without upper cubicle

Fig 2) Whole Load break switch outline