2. BU 3420 - MV fuses / MV Switch Disconnectors
Indoor
NAL/F
AIRSWITCH series
BWMW
Rotary type:
CEF AM

3. BU 3420 - Switch Disconnector type NAL/F
Type NAL / F - INDOOR
Based on modular principle
Simply and reliable design,
A lot of additional equipment,
Wide range of application with easy installation and maintenance.

4. BU 3420 - Switch Disconnector type NAL/F
12, 17,5 i 24 kV / 400, 630 i 1250 A kV / 630 i 800 A

5. BU 3420 - Switch Disconnector type NAL/F
3-pole switch disconnector and switch fuse combination
IEC (actual: IEC ) close / open operations at 630 A
Class E1 24kV
Class E3 12/17,5/36 kV
IEC 420 (actual: IEC ) Alternating current switch-fuse combinations
More than units in service world wide
Production capacity of units per annum

6. BU 3420 - Switch Disconnector type NAL/F

7. BU 3420 - NAL Switches – main types of switches

8. BU 3420 - NAL Switches – main types of switches

9. BU 3420 - Switch Disconnector type NAL/F
Auxiliary switch
2;4;8NO+NC
Motor operation
on switch mounted
Shaft extension for
Left-Hand side operation
Mechanical interlocking
Earthing switch type E
Operating mechanism
Hand operating type HE
(upper part)
- bevel gear
Operating handle
Auxiliary switch for installation
Of fuse interruption
Shunt trip coil for
A-mechanism
(lower part)
Front bearing
Motor operation mounted
in front

10. BU 3420 - Switch Disconnector type NAL/F
Earthing switch type EB
For separate installation
Quick make earthing switch type E

11. BU 3420 - Switch Disconnector type NAL/F
Earthing switches
Earthing switches with making
capacity
Mounted on pivot side of the
switch or on fuse base
Mechanical interlocking
Earthing switch for separate
installation

12. BU 3420 - Switch Disconnector type NAL/F
UEMC 40 K3
NM 24…220
Type UEMC 40 K3 /NM mounted on the mechanism
Type UEMC 40 A mounted on the front panel

13. BU 3420 - Switch Disconnector type NAL/F1 2 3
1. Latched snap action - type KS
2. Stored spring energy – type A
With two springs
3. Snap action -type K
With one spring

14. Hand operating mechanism type HE:
BU Switch Disconnector type NAL/F
Hand operating mechanism type HE:
Bevel gear
Connection rod
Front bearing with cardanic joint- optional blocking coil
Operating handle
Shaft extension
- Left – hand side operation
- Mechanical interlocking

15. BU 3420 - Switch Disconnector type NAL/F
Mounting example for hand operating mechanism
90 - Transmission with HE

16. BU 3420 - Switch Disconnector type NAL/F
Applications
Cable sectionalizer and transformer switch
Motor switch (with motor fuse CMF)
Switching of capacitor banks
Component for local manufactured panels
Used in switch cubicles
Compact substation (kiosk)
Utility and industrial application

17. BU 3420 - Switch Disconnector type NAL/F
Application example

18. BU 3420 - Switch Disconnector type NAL/F
Applications
NAL in substation
NAL in UniSafe and UniGear cubicle

19. BU 3420 - Switch Disconnector type NAL/F
Open switch

20. BU 3420 - Switch Disconnector type NAL/F
Connecting of the switch
Connecting main knife

21. BU 3420 - Switch Disconnector type NAL/F
Connected switch

22. BU 3420 - Switch Disconnector type NAL/F
Switching off
flame arc breaking

23. BU 3420 - Switch Disconnector type NAL/F

24. BU 3420 - Switch Disconnector type NAL/F

25. BU 3420 – AirSwitch series Available in two versions:
The switchboard ROTARY switches and isolators AM
AR/AS
Available in two versions:
AM type switch disconnector
(24kV; 400/630A)
AR/AS type rotary isolators
(24kV; 400/630/ 800/1250A)

26. BU 3420 - Switch Disconnector type AM
Switch Disconnector AM
Air-insulated
Rotary type
630 A breaking capacity
40 kA making capacity
2 positions: LINE – OPEN
Provide segregation between busbar and feeder compartments
Interlocked with a separate eathing switch

27. BU 3420 - Switch Disconnector type AM
Switch Disconnector AM
Voltage signalling device
Key lock
Door lock
Auxliary contacts
Shunt opening release

28. BU 3420 - Isolators type AR/AS
Switch Isolator AS/AR
Air-insulated
Rotary type
400, 630, 800, 1250 A rated current
up to 25 kA short time withstand current

29. BU 3420 - Isolators type AR/AS
Isolators AR/AS
Voltage signalling device
Key lock
Door lock
Auxliary contacts

30. BU 3420 - Switch Disconnector type AM
Switch disconnector applications

31. BU 3420 - Switch Disconnector type AM
Switch disconnector with fuses 1 2 3
Caption:
1 Busbars
2 Switch Disconnector
3 Fuses
4 Earthing switch
5 Cable fixing point 5 4

32. BU 3420 – Isolators type AR/AS
Isolators applications

33. BU 3420

34. BU 3420 – Switches AUSTRALIA CHINA HONG KONG INDIA INDONESIA JAPAN
ASIA:
AUSTRALIA
CHINA
HONG KONG
INDIA
INDONESIA
JAPAN
KOREA
NEW ZEALAND
MALAYSIA
PAKISTAN
PHILIPPINES
SINGAPORE
TAIWAN
THAILAND
VIETNAM
EUROPE: WE+CEE
AUSTRIA
BELGIUM
BELARUS
BULGARIA
CROATIA
CZECH REP.
DENMARK
ESTONIA
FINLAND
GERMANY
GREAT BRITAIN
GREECE
HUNGARY
ICELAND
IRELAND
ITALY
LATVIA
LITHUANIA
LUXEMBOURG
NORWAY
POLAND
PORTUGAL
ROMANIA
SLOVAKIA
SPAIN
SWEDEN
SWITZERLAND
MIDDLE EAST:
ARAB EMIRATES
EGYPT
IRAN
ISRAEL
JORDAN
LEBANON
OMAN
QATAR
SAUDI ARABIA
SYRIA
TUNISIA
TURKEY
SOUTH&NORTH AMERICA:
ARGENTINA
BOLIVIA
BRAZIL
CANADA
CHILE
COLOMBIA
ECUADOR
MEXICO
PARAGUAY
PERU
USA
VENEZUELA
AFRICA:
SENEGAL
SOUTH AFRICA
TANZANIA

35. BU 3420 - Switch Disconnector type NAL/F
Modern machinery
ISO 9001/14001 certified
IEC; ANSI, CSA, GOST Standards

36. BU 3420

37. BU 3420 – switch disconnectors – normal operating conditions
Maximum ambient temperature +400C
Minimum ambient temperature is -250C
The altitude does not exceed 1000m (3300ft)
The ambient air is not excessively polluted by dust, smoke,
corrosive or flammable gases, vapour or salt
Typical conditions of humidity for indoor installations are
fulfilled

38. BU 3420 - switch disconnectors – Standards
IEC Switches for voltage above 1 kV and less than 52 kV
IEC Common specification for high-voltage switchgear
and controlgear standards
IEC Alternating current disconnectors and earthing
switches
IEC High voltage switchgear and controlgear
Part 105-Alternating current switch-fuse combinations
former name IEC 420

39. BU 3420 - switch disconnectors – application
Altitude correction factors for Test and Rating Voltages
Altitude correction factors for Rated Current and Temperature Rise

40. BU 3420 - switch disconnectors – Switch-fuse ratings
Switch nameplate

41. BU 3420 - switch disconnectors – breaking capacity

42. BU 3420 - switch disconnectors – breaking capacity

43. BU 3420 - switch disconnectors – breaking capacity

44. BU 3420 - switch disconnectors – breaking capacity

45. BU 3420 - switch disconnectors – breaking capacity

46. BU 3420 - switch disconnectors – breaking capacity

47. BU 3420 - HV fuses – Coordination with load break switch
Minimum breaking current with switch disconnector coordination

48. BU 3420 - switch disconnectors – Operating methods
When using NALF - A or KS operating mechanism are suitable only

49. BU 3420 - switch disconnectors – Operating methods

50. BU 3420 - switch disconnectors – Coordination with switch
Transfer current (striker operation)
value of the three-phase symmetrical current at which the fuses and the switch exchange breaking duties
NOTE Above this value the three-phase current is interrupted by the fuse only. Immediately below this value, the current in the first-pole-to-clear is interrupted by the fuse and the current in the other two poles by the switch, or by the fuses, depending on the tolerances of the fuse time current characteristic and the fuse-initiated opening time of the switch.

51. BU 3420 - HV fuses – Coordination with load break switch

52. BU 3420 - HV fuses – Coordination with load break switch
The fuses are incorporated in order to extend the short-circuit breaking rating of the combination beyond that of the switch alone. They are fitted with strikers in order both to open automatically all three poles of the switch on the operation of a fuse and to achieve a correct operation at values of fault current above the minimum melting current but below the minimum breaking current of the fuses
The minimum breaking current is normally in the range from 2 to 7 times fuse rated current (dependent of fuse rated current). Naturally the question is what will happen if we get a fault current in the range from minimum melting to minimum breaking current?
If this happen, when the last conductor melts off, an arc starts and we get an arc voltage between the fuse terminals as described earlier. The fuse will withstand the arc and the energy dissipated for 200 to 400 ms. Due to the arc voltage the striker system will operate and combined with a load break switch, tripping on signal from the striker, the load break switch will open and interrupt the current before the fuse is damaged.

53. BU 3420 - HV fuses – Coordination with load break switch
That means in the range from minimum melting current to minimum breaking current the fuse gives the signal and the breaker clears the fault. In this way by combining a load break switch with a pre charged operated mechanism which can be tripped by the fuse striker system, we can obtain protection from minimum melting current and up to the max breaking current for the fuse.
When we reach a certain fault current level the fuse will break and clear the fault before the breaker is able to open due to the mechanical operating time of the switch (this is normally ms dependent of type) and we do not get any problem with the breaking capacity of the load break switch, the fuse has already cleared the fault when the breaker opens. We will have a certain range where fuse and switch have approximately same clearing time. This happen at the take over current as shown on earlier slide.
The switch itself must have a max. breaking capacity which overlaps the take over point. The requirement to a fuse switch combination is given in IEC (former IEC 420). and will determine what max. rated current the fuse can have to be sure you have the necessary safety margin for coordination between fuse and switch.

54. BU 3420 - switch disconnectors – general rules
Low over-currents

55. BU 3420 - switch disconnectors – general rules
Minimum breaking current

56. BU 3420 - HV fuses – general rules

57. BU 3420 - HV fuses – Coordination with load break switch

58. BU 3420 - HV fuses – Coordination with load break switch

59. BU 3420 - HV fuses – Coordination with load break switch

60. BU 3420 - HV fuses – Coordination with load break switch

61. BU 3420 - HV fuses – Coordination with load break switch

62. BU 3420 - NAL Switches – Tightening forces

63. BU 3420 - NAL Switches – Assembling mistakes

64. BU 3420 - NAL Switches – Assembling mistakes

65. BU 3420 - NAL Switches – Assembling mistakes

66. BU 3420 - NAL Switches – Your questions?

67. © BA PTMV – Page41