Three-phased earthing device for bus bars

Three-phased earthing device for bus bars

    

Code: Msp – C – 3xSf/lf – Sp/lp – P/p 
           Msp – CA – 3xSf/lf – Sp/lp – P/p 
           Msp – CAU – 3xSf/lf – Sp/lp – S/P/p 

The thrree-phased earthing device is applied on the bus bars of the medium voltage indoor substations.
The phase clamp can be classic (C), automatic (CA) or universal automatic (CAU) and is directly applied on the bus bar.
The earthing device provided with CAU universal automatic clamp can be applied also on spherical pieces permanently mounted on the bus bars of the MV indoor substations.

The C classical clamp and the CA automatic clamp contain a molded body made of aluminum alloy, all the clamps having a tightening screw provided at the end with a bayonet coupling system for the connection with the insulating stic. The CAU universal automatic clamp has an extruded aluminum alloy body.

General characteristics for the three-phased earthing devices for bus bars

Earthing cable section Sp (mm2)

16

25

35

50

70

95

120

Nominal short-circuiting current for t = 1s Isc (kA)

3,5

6

8

12

16

20

30

Nominal peak currrent for t = 0,02 s Isd (kA)

8,75

15

20

30

40

50

75

Testing shortcircuiting current for t = 1s (kA)

4,6

6,9

9,2

13,8

18,4

23

34,5

Testing peak current for  t = 0,02 s (kA)

11,5

17,25

23

34,5

46

57,5

86,25

Maximum length of the earthing cable lp (m) – classic reduced clamp (Cr)

17,5

17,5

17,5

17,5

17,5

10

10

 Peak factor (SR EN 61230)

 2,5

 

Type of phase clamp

Classic
clamp (C)

Automatic
clamp (CA)

Universal automatic
clamp (CAU)

Short-circuiting cables length lf (m)

max. 1,5

max. 1,5

max. 1,5

 Earthing cable length lp (m)

 max. 7

  max. 7

  max.8,5

 Thickness of the bus bar on which the phase clamp can be mounted (mm)

  max.40

  max. 37

  max. 37

Diameter of the spherical coupling piece (mm)

 –

 –

 30

The three-phased earthing device is composed of:
     – Phase clamps – 3 pieces
     – Short-circuiting cables  – 3 pieces
     – Earthing cable – 1 piece
     – Earthing clamp – 1 piece

 The three-phased earthing device is delivered in a transport bag / case.