Selecting MV Bushings & Cable Connectors For Use With Schneider Switchgear (Medium Voltage)

Published 23 Jan 2018

Schneider Switchgear Nexans Euromold Connectors

Schneider Gas Insulated (SF6) Switchgear, RMU’s & MV Medium Voltage Electrical Equipment

  • Uploaded by Chris Dodds – reading time 8 minutes

Switchgear Bushings & Cable Connectors

The following information has been provided to enable to correct selection and specification of MV Bushings and Separable Connectors used to connect and terminate medium/high voltage power cables into Schneider RM6 gas insulated switchgear and Ring Main Units (RMU) up to 24kV.

General

  • The profiles, contacts and dimensions of the Schneider RM6 connection interfaces are defined by the IEC 60137 standard
  • 100% of the epoxy resin interfaces undergo dielectric testing at power frequency and partial discharge tests
  • Insulated connectors must be used in order to guarantee the dielectric performance

Appropriateness For Use

Types of connection interface

Types of Connection Interface

The bushings carry the electrical current from the outside to the inside of the MV switchgear enclosure, which is filled with SF6 gas, ensuring insulation between the live conductors and the frame for MV power distribution.

There are 3 types of MV bushing, which are defined by their short-time withstand current:

  • Type A Interface Bushing: 200 A: 12.5 kA 1 s and 31.5 kA peak (plug-in)
  • Type B Interface Bushing: 400 A: 16 kA 1 s and 40 kA peak (plug-in)
  • Type C Interface Bushing: 630 A: 25 kA 1 s, 21 kA 3 s + 62.5 kA peak (disconnectable M16)

➡ For further information on Euromold Connectors for all other Interface Bushings up to 66kV please see the following information:

Nexans Euromold Separable Connectors MV HV Elbows Tees Plugs - Interface A Nexans Euromold Separable Connectors MV HV Elbows Tees Plugs - Interface C Symmetrical Nexans Euromold Separable Connectors MV HV Elbows Tees Plugs - Interface D Nexans Euromold Separable Connectors MV HV Elbows Tees Plugs - Interface F
Nexans Euromold

The Euromold brand of MV Cable Connectors manufactured by Nexans for 11kV 33kV 66kV connection of medium/high voltage power cables into gas insulated electrical equipment.

How To Define The Cable Connectors Interface

The connection interfaces depend on specific criteria, such as:

Installation

  • Current rating of the connected equipment: 200, 400, 630 A
  • Short-time withstand current for 12.5 kA, 16 kA, 25 kA switch and circuit breaker functions
  • For the fuse-switch combination function, as the short-circuit current is limited by the fuse, the connection interface will be of type A (200 A)
  • Minimum phase expansion length
  • Connection type: plug in: multicontact ring, disconnectable: bolted
  • Output position: straight or elbow connectors

MV Medium Voltage Cable

  • Specified voltage: of the cable, of the network
  • Type of conductor: aluminium or copper
  • Cross section in mm2
  • Primary insulation diameter
  • Cable composition: single-core or 3-core
  • Insulation type: dry, paper impregnated (non-draining type)
  • Type of screen: copper tape or copper wire screen
  • Armour: SWA (steel wire armour), AWA (aluminium wire armour) or unarmoured (copper wire screened)

Gas Insulated Switchgear – Schneider RM6

  1. Stainless steel tank filled with SF6 gas, sealed for life and containing the medium voltage (MV) busbar and all live switching components such as the switch-disconnector, earthing switch, the fuse switch combination or the MV circuit breaker
  2. One of the five cable compartments with interfaces to connect to the network or medium voltage transformer
  3. User interface with single line diagram, actuators and LV components
  4. Manual or motorised operating mechanism compartments
  5. Earthing circuit with visible earthing contacts

Nexans Connectors

Type A Bushing – Directed field plug-in connector

Dry single-core cable

Performance Cable Connection Manufacturer Connector Reference Cross Section sqmm  Comments
7.2 to 10 kV200 A -95 kV impulse Plug-in Euromold | Elastimold 158LR 16 to 120 T-shaped elbow (Tee)
Euromold | Elastimold 151SR 16 to 120 Straight, Q function only
Prysmian FMCE 250 16 to 95
7.2 to 17.5 kV200 A -95 kV impulse Plug-in nkt cables GmbH EASW 12/250 A 25 to 95 Shaped elbow connector
nkt cables GmbH EASG 12/250 A 25 to 95 Straight
Tyco Electronics RSES-52xx 25 to 120 Shaped elbow
Tyco Electronics RSSS-52xx 25 to 95 Straight connection
7.2 to 24 kV200 A -125 kV impulse Plug-in Elastimold K158LR 16 to 95 T-shaped elbow connector (Tee)
24 kV200 A -125 kV impulse Plug-in nkt cables GmbH EASW 20/250 A 25 to 95 Shaped elbow
nkt cables GmbH EASG 20/250 A 25 to 95 Straight connector
Tyco Electronics RSES-52xx 25 to 120 Shaped elbow
Tyco Electronics RSSS-52xx 25 to 95 Straight connector

 

Further information link: Elastimold Connectors

 

Type A/M8 bushing – Non-directed field disconnectable connector (*)

Dry single and 3-core cable

Performance Cable Connection Manufacturer Cable Termination Reference Cross Section sqmm  Comments
7.2 to 17.5 kV200 A -95 kV impulse Heat Shrink Cable Termination Tyco Electronics EPKT + EAKT + RSRB 16 to 150
Insulating Boots ABB Kabeldon KAP70 70 max

(*) 520 mm plinth must be used

Type B bushing Directed field plug-in connector

Dry single-core cable

Performance Cable Connection Manufacturer Connector Reference Cross Section sqmm  Comments
7.2 to 10 kV400 A-95 kV impulse Plug-in Elastimold | Euromold Euromold 400LR 70 to 240 Limited to Us = 10 kV
7.2 to 17.5 kV400 A-95 kV impulse Plug-in nkt cables GmbH CE 12-400 25 to 300
Tyco Electronics RSES-54xx 25 to 300 Shaped elbow connector
24 kV400 A-125 kV impulse Plug-in Prysmian FMCE 400 70 to 300
Elastimold | Euromold Euromold K400LR 35 to 240
ABB Kabeldon SOC 630 50 to 300
nkt cables GmbH CE 24-400 25 to 300
Tyco Electronics RSES-54xx 25 to 300 Shaped elbow connector

 

Type C bushing – Directed field disconnectable connector

Dry single-core cable

Performance Cable Connection Manufacturer Connector Reference Cross Section sqmm  Comments
7.2 to 10 kV630 A-95 kV impulse Disconnectable Elastimold | Euromold Euromold 440TB 70 to 240
7.2 to 17.5 kV630 A-95 kV impulse Disconnectable nkt cables GmbH CB 12-630 25 to 300
Tyco Electronics RSTI-58xx 25 to 300 “T”-shaped connector (Tee)
7.2 to 24 kV630 A-125 kV impulse Disconnectable Prysmian FMCTs 400 70 to 300
Elastimold | Euromold Euromold K400TB 35 to 240
ABB Kabeldon SOC 630 50 to 300
24 kV630 A-125 kV impulse Disconnectable nkt cables GmbH CB 24-630 25 to 300
Tyco Electronics RSTI-58xx 25 to 300 “T”-shaped connector (Tee)

 

Non-directed field disconnectable connector

Dry single and three-core cable

Performance Cable Connection Manufacturer Cable Termination Reference Cross Section sqmm  Comments
7.2 to 10 kV630 A -95 kV impulse Heat Shrink Cable Termination Tyco Electronics EPKT + EAKT + RSRB 16 to 300
Sigmaform Q-CAP 16 to 300
Insulating Boots Kabeldon SOC 630 50 to 300 Completed by a kit for three core-pole cable
Simplified Disconnectable Tyco Electronics RICS + EPKT 25 to 300
 Universal Bushing Boots Euromold 15TS-NSS 50 to 300 Limited to Us = 20 kV
24 kV630 A -125 kV impulse Disconnectable nkt cables GmbH AB 12-630 25 to 300 (+ATS) For 3-core cable
Simplified Disconnectable Tyco Electronics RICS + EPKT 25 to 300

 

Non-directed field disconnectable connector

Single-core cable, paper impregnated, non-draining type

Performance Cable Termination Manufacturer Cable Termination Reference Cross Section sqmm  Comments
7.2 to 17.5 kV630 A-95 kV impulse Insulating Bushing Boots ABB Kabeldon SOC 25 to 300
Simplified Disconnectable Tyco Electronics RICS – EPKT 25 to 300
Heat Shrink Cable Termination Tyco Electronics EPKT+EAKT+RSRB 95 to 300
24 kV630 A-125 kV impulse Simplified Disconnectable Tyco Electronics RICS – EPKT 25 to 300

 

Non-directed field disconnectable connector

Three-core cable, paper impregnated, non-draining type

Performance Cable Termination Manufacturer Cable Termination Reference Cross Section sqmm  Comments
7.2 to 17.5 kV630 A-95 kV impulse Insulating Boots ABB Kabeldon SOC 630 25 to 300
Simplified Disconnectable Tyco Electronics RICS – EPKT 25 to 300
Heat Shrinkable Termination Tyco Electronics EPKT+EAKT+RSRB 16 to 300
24 kV630 A-125 kV impulse Simplified Disconnectable Tyco Electronics RICS – EPKT 25 to 300

 

Disconnectable Connector Single-core Dry Cable &

MV Medium Voltage Lightning Arrestor

Performance Cable Connection Manufacturer Cable Termination Reference Cross Section sqmm  Comments
7.2 to 17.5 kV630 A-95 kV impulse Disconnectable nkt cables GmbH AB 12-630 + ASA12(5 or 10 kA) 25 to 300 Non-directed field
CB 24-630 + CSA 24(5 or 10 kA) 25 to 300 Directed field
24 kV630 A-125 kV impulse Disconnectable nkt cables GmbH AB 12-630 + ASA12(5 or 10 kA) 25 to 300 Non-directed field
CB 24-630 + CSA 24(5 or 10 kA) 25 to 300 Directed field
7.2 to 17.5 kV630 A-95 kV impulse Disconnectable Tyco Electronics RICS+EPKTRDA 12 or 18 25 to 300
Elastimold | Euromold K400TB + K400RTPA+ K156SA 35 to 300 Cable box enlarged
24 kV630 A-125 kV impulse Disconnectable Tyco Electronics RICS + EPKTRDA 24 25 to 300
Elastimold | Euromold K440TB + K400RTPA+ K156SA 35 to 300 Cable box enlarged
Tyco Electronics RSTI-58 + RSTI-CC-58SAxx05 25 to 300 Directed field 5 kA arrestor
Tyco Electronics RSTI-58 + RSTI-CC-66SAxx10M16 25 to 300 Directed field 10 kA arrestor

Nexans

See How Thorne & Derrick & Nexans Euromold can support your MV Bushings & Connectors requirements

 

Thorne & Derrick International

Since 1985 Thorne & Derrick based in the UK have been specialist distributors of LV, MV & HV Cable Installation, Jointing, Substation, Arc Flash Clothing & Electrical Safety Equipment – customers include UK and worldwide contractors, specifiers, traders and end-users involved in medium and high voltage cable installations, cable jointing, substation, overhead line and electrical construction.

We are specialist stockists and distributors of 11kV-33kV Cable Joints, Terminations & Connectors from manufacturers including 3M, Pfisterer, Prysmian and Nexans Euromold in a selection of cable jointing technologies including push-on, heat shrink and cold shrink joints and cold shrink terminations.

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MV HV | Medium & High Voltage Power Products, Tools, Cables & Electrical Equipment

Further Reading