3M-電力接地帶
Electrical Grounding Braid
● 25 電力接地銅帶是一種接地用鍍錫編織銅帶。
● 可承受6AWG 導體所能承受之電流負戴容量。
● 由240 股的30AWG 鍍錫銅線所編織而成之編織帶，故柔軟而適形性良好。
● 一般使於電纜遮蔽型接頭或終端接頭之接地用。
Product Description
Scotch 25 Electrical Grounding Braid is an all-metal woven grounding braid in a flat, cable -like form. It is conformable due to its woven construction of 240 strands of #30 AWG tinned copper wires.
Features
●High current-carrying capacity (approximately that of #6 AWG wire)
●Tinned copper wires
●Stable at elevated temperatures
●Oil resistant
●Compatible with all power cable installations
●Fire resistant
●Easy conformity to irregular surfaces
●Corrosion resistant
●Compatible with high-voltage jointing and termination materials
●Unaffected by solvents, ultra-violet, ozone, and moisture
●Usable for indoor and outdoor applications
●Can be easily soldered to high-voltage cable shields
Applications
●To provide a fault current path across shielded cable joints
●For grounding high-voltage joints, terminations, cables or other cable accessories
Specifications
●Product
Conducting metal braid must be woven from 240 strands of #30 AWG tinned copper wires and be capable of carrying fault current comparable to that of #6 AWG copper wire. It must be usable with or without covering, both indoors and outdoors, without corroding, tearing or splitting. It must be capable of being soldered to high voltage cable shields while being non-flammable and yet must be compatible with cable oils, common solvents, adhesives and high-voltage jointing and terminating insulations.
●Engineering/Architectural Specifications
Jointing and terminating shall be done according to the engineering print supplied by the manufacturer of the jointing or terminating materials for the specific cable and approved by the specifying engineer.
●Alternate
Jointing and terminating engineering drawing shall be compatible with specific cable or cables and approved for specific voltage of cable.
Characteristics and Test Data
Test method, as show in Figure 1 was designed to determine fault current carrying capacity of a 30.5cm specimen of 25 Braid. The test ended when the braid separated, due to melting of tinned copper wires. Graph (Figure 2) illustrates the results.
The data indicate that 25 Braid has excellent fault current carrying capacities for replacing shielding in high-voltage cables. It can be used as a ground strap or jumper wire because it can carry fault currents and lightning currents that can appear in high-voltage cables. Figure 3 is representative of the method used for testing fault current carrying capacities of 25 Braid in a high-voltage cable joint.
Every cable tested had a single half-lapped layer of 19mm x 0.13mm tinned copper metallic shielding tape for fault current protection. In all cases, the cable’s metallic shield was destroyed (by current), whereas, grounding braid remained unharmed.
Installation Techniques
When grounding termination or joints:
Solder Scotch 25 Ground Braid to cable metallic shields and bring remainder of braid out of joint or termination. Construct a 51mm solder block on ground braid to prevent moisture penetration into joint.
Figure 4.
Wrap two half-lapped layers of Scotch 130C Rubber Jointing Tape, covering the end 51mm of cable jacket. Wrap two half-lapped layers of 130 Tape for 76mm along ground braid, beginning at a point where ground is soldered to shield.
Lay ground braid over 130C Tape applied on jacket for 25mm then bend strap away from cable. Apply outer sheath over ground braid. For bonding jumper wire across joint, lay Scotch 25 Ground Braid across joint and solder ends to cable’s metallic shielding.
Maintenance
25 Braid has an indefinite storage life and is not impaired by freezing nor by over-heated conditions. Braid can be checked for flaws by visual inspection.
Availability
Scotch 25 Braid is available in 12.7mm x 2.38mm x 4.57mm and is available from your local 3M authorized electrical distributor.
Save
Download Datasheet
