Three phase earthing device for bus bars


Category:

    

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

The single phase earthing device for bus bars (rectangular conductors, flat bars) can be provided with one of the following phase clamps:
 Classic phase clamp, C type (casting from aluminium alloy);
 Universal classic phase clamp, CCU type (extrusion of aluminium alloy);
 Automatic phase clamp, CA type (casting from aluminium alloy);
 Automatic extruded phase clamp, CAE type (extrusion of aluminium alloy);
 Universal automatic phase clamp, CAU type (extrusion of aluminium alloy).

All types of phase clamps have a fixing system on the bar, consisting of a mobile die operated by a tightening screw. This screw is provided – to its extremity – with a bayonet coupling system which allows a quick and safe connection at the insulating stick. The automatic phase clamps are additionally provided with a special system which allows a preliminary fastening of the clamp on bar (by acting the mobile die). This preliminary fastening is triggered by a lightly knocking of the clamp by bar and must be followed by a firm fastening obtained by screwing.

The earthing clamp can be classic (standard models) or with scrapping die (optional models), adapted to the short-circuiting current of the earthing device. The length of the earthing cable should be chosen depending on the positions of application points for phase clamp and earthing clamp. The cross-section of the earthing cable should by chosen depending on the required short-circuiting current.

This equipment is delivered in a carrying bag or a transport case.

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General characteristics for 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)

C / CA / CAE

3,5

6

8

12

16

20

30

CCU / CAU

4

6,25

8,75

12,5

16

23,75

30

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

Isd = 2,5 x Isc

Testing short-circuiting current for t = 1s Itest (kA)

Itest = 1,15 x Isc

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

Ipeak = 1,15 x Isd

Peak factor (SR EN 61230)

2,5

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Phase clamp type

Classic clamp (C) Universal classic clamp (CCU) Automatic clamp (CA) Automatic extruded clamp (CAE) Universal automatic clamp (CAU)

Short-circuiting cable length lf (m)

max. 1,5 max. 1,5 max. 1,5 max. 1,5 max. 1,5

Earthing cable length lp (m)

max. 7 max. 8,5 max. 7 max. 7 max. 8,5

Thickness of rectangular conductor on which can be mounted the phase clamp g (mm)

max. 40 max. 40 max. 37 max. 36 max. 37

Diameter of coupling piece spherical type (mm)

30 30

 

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