Fast Earthing switch FES-12
The FES-12 series Fast Earthing switch (FES) is designed to operate as part of Switchgear Panels / Cubicles in three-phase AC networks with a frequency of 50 Hz, nominal voltage of 7.2 or 12 kV, with an isolated neutral or a neutral grounded through an arc-suppression reactor or resistor. The FES is equipped with a spring drive; its toggle spring ensures the movement of grounding blades at a speed independent of the operator's switching speed.
For visual status monitoring, the FES is equipped with a (mechanical) position indicator.
The FES is equipped with Limit switch (auxiliary contacts) for status indication, which are located either on its housing or on the drive shaft, depending on the configuration.
The Fast Earthing switches are designed for the full short-circuit current; they have all the necessary interlocks with the circuit breaker's chassis cart, as well as operational interlocks for external connections. They are fixed in the ON and OFF positions.
For visual status monitoring, the FES is equipped with a (mechanical) position indicator.
The FES is equipped with Limit switch (auxiliary contacts) for status indication, which are located either on its housing or on the drive shaft, depending on the configuration.
The Fast Earthing switches are designed for the full short-circuit current; they have all the necessary interlocks with the circuit breaker's chassis cart, as well as operational interlocks for external connections. They are fixed in the ON and OFF positions.
Technical characteristics:
Parameter
Value
Nominal voltage, kV
12
Highest operating voltage, kV
12
Short-time withstand current (1 sec.), kA
31,5
Peak withstand current, kA
81
Power-frequency withstand voltages of the main circuit insulation, kV:
– 1 min
– lightning impulse
– 1 min
– lightning impulse
– 42
– 75
– 75
Main circuit resistance (per phase), µΩ, no more than
280
Mechanical endurance (number of C-O cycles before major overhaul)
1000
Service life before decommissioning, years, no less than
10
Versions of Fast Earthing switches
FES EK6 (version 01) - standard version
FES JN15 (version 02) - with pre-installed post insulators and static contacts. (Capacitive insulators CG3 for voltage indication can be installed as post insulators)
Fast Earthing switches are supplied in two versions: FES EK6 (version 01) – standard; FES JN15 (version 02) – with pre-installed post insulators and static contacts fixed on them. At the customer's request, capacitive insulators CG3 can be installed as post insulators.
Fast Earthing switch with drive (FES EK6)
Base of FES
Toggle spring
Shaft of FES
Movable contacts (blades)
Position indicator of FES
Bevel gear
Drive shaft of FES
Control window
Interlock kit for chassis cart
Access block to FES control
The delivery set also includes a bevel gear (6). The interlock kit for the chassis cart (9) is ordered optionally. At the customer's request, the interlock kit can be supplemented with guide rails for a mid-mounted chassis cart, as well as a curtain mechanism.
Fast Earthing switch with drive (FES JN15)
Base of FES
Toggle spring
Shaft of FES
Movable contacts (blades)
Static contacts
Drive levers of FES
Drive shaft of FES
Control window
Interlock kit for chassis cart
Access block to FES control
The delivery set also includes an adjustable pull rod connecting the levers (6). The interlock kit for the chassis cart (9) is ordered optionally. At the customer's request, the interlock kit can be supplemented with guide rails for a mid-mounted chassis cart, as well as a curtain mechanism.
Overall and mounting dimensions
"ON" position
"OFF" position
For the FES-12/31.5-150 version - insulating dividing partitions are included in the delivery set.
Table 1:
Designation
L, mm
L1, mm
L2, mm
L3, mm
FES-12/31.5-150
535
204
150
160
FES-12/31.5-210
655
324
210
185
FES-12/31.5-275
810
454
275
210
Static contact of FES
Any additional information, drawings, as well as 3D models of any Fast Earthing switch version are available upon request.