MILE MP 12,MP17 and MP 24

The MILE MP series switchgear is designed for primary distribution networks with the rated voltages of 12kV, 17.5kV and 24kV 50/60Hz intended for indoor installation. The MILE MP series switchgear  is  air-insulated  LSC2B-PM class, with single busbar design. The switchgear concept meets today's owner requirements such  as reliability, personnel and operational safety, economy and efficiency in an optimal way.

The switchgear is modular and is built up by placing standardized units side by side in a coordinated way. The switchgear is easy to configure and selection  of the apparatus  and instruments  does not imply dedicated solutions.

The functional units of the switchgear are guaranteed arc proof AFLR 31,5kA  1s in accordance with the IEC 62271-200 standard, appendix AA, class A  accessibility, criteria 1 to 5. All the start-up, maintenance and service  operations  can  be  carried  out  from the  front.  The switchgear and the earthing switches are operated from the  front with the  door closed. The MILE  MP  series  switchgear can be with front access  or with  front and rear access.

Type testing

The MILE  switchgear has successfully passed all the tests specified by relevant IEC (International  Standard) and GOST  (Russian national  standard) standards.  As noted  within the  regulations  of these  standards, the tests were carried out on the switchgear units considered to be the most sensitive to stresses applied within the tests and therefore assigned to be valid on the whole range.

Degrees of protection

The degrees of protection of the switchgear conforms with IEC 60529  tandard. The  MILE MP series switchgear is  normally  supplied  with  the   following  standard degrees of protection:

IP4X on the external housing

IP3X with the doors open

IP 42 on request

Normal service conditions

The rated characteristics of the switchgear are guaranteed under the following ambient conditions:

*with   selected microprocessor   electronic only
**in accordance with IEC 60721-2-1 for altitudes above 100m,it is required to take into  consideration the decrease of dielectrical strength applying factor from the table

The MILE MP series switchgear are suitable for operation in the climate of Wda type in accordance with IEC  60721-2-1 standard.

Vacuum  Circuit  Breaker

MILE switchgear  is  designed  solely for Tavrida Electric advanced vacuum  circuit  breakers.  Tavrida Electric has  simplified  the  mechanical structure of the circuit breaker  to the greatest possible degree. It uses  three  single-coil  magnetic actuators, one  per pole.  All switching  elements are assembled along  a single axis. All mechanical movements are therefore direct and linear. The three  actuators are mounted in a steel frame and are mechanically  linked by a synchronizing shaft.

Completely avoided is failure of critical components such as

•  mechanical  latching

• gears, chains, bearings and levers

• tripping and closing coils

• motors  to charge springs

The result is up to 150,000 C-O cycles at rated current or up to 100 operations at full short circuit breaking current without the need to replace or adjust any parts.Tavrida Electric vacuum circuit breakers are maintenance free over the total life expectancy of at least 25 years.

Main Busbars

Main busbars rated current , А	Busbar, mm x mm
1250	1*10*80
2000	2*10*80
2500	3*10*80
3150	3*10*100

Magnetic actuator

The actuator is held in its two end positions without the use of mechanical latches:

in the OPEN position the armature is held by the opening spring in the CLOSED position the armature is held by the magnetic flux produced by a ring magnet.This actuator  has only one coil. To close and trip the  actuator it is necessary to inject current into the coil in different directions.

Vacuum interrupters

Several major benefits result from this design:

• high interrupting capacity;

• very compact dimensions;

• low  chopping  current  (4-5   amps)  This   limits inductive switching over voltages to safe values;

• Axial magnetic field minimizes contact erosion and ensures a very long and reliable life.

CONTROL  MODULE   DESIGN

The control module is intended for actuator operations using the energy stored in the closing and opening capacitors. It is an intelligent, microprocessor-based device capable of providing optimal control of the magnetic actuators irrespective of the quality of external power or environmental effects. The module also incorporates monitoring features providing supervision of the state of the magnetic actuator coil circuit as well as self-monitoring functionality.

The control modules are totally enclosed in an extruded aluminum housing designed for   simple,  flat  surface, 4-hole  mounting.

Basic   Structure

An indoor switchboard consists of different number and types of MP panels with switching devices, control and protection relays, signaling and metering devices and Other  auxiliary equipment, which are interconnected by control cabling. The basic structures of the MP panels are given below.
Cross-Section

Cassette type

1. Vacuum circuit breaker	15. Bushing insulators
2. Voltage transformer aux connector 1	16. Earthing switch (make type)
3. Support insulator with a voltage indicator	17. Current transformers
4. Vacuum circuit breaker	18. Surge arresters
5. Circuit breaker aux connector	19. Outgoing cables
6. Live shutters	20. Bottom with sealed cable entries
7. Busbar earthing switch operation switch	21. Main earthing bar
8. Earthing switch control box	22. Earthing switch operation slot
9. Circuit breaker pressure relief flap	23. Ventilation provision
10. Operation mechanism for earthing switch	24. Cassette operation slot
11. Busbar compartment pressure relief flap	25. Circuit breaker emergency trip
12. Earthing switch top installation	26. Permission for operation with draw-out unit
13. Cable compartment pressure relief flap	27. Inspection window
14. Through insulator

Overall Dimension

A- Busbar Compartment

B- Circuit Breaker Compartment

C- Low-Volatge Compartment

D- Cable Compartment

 

 

 

 

 

Voltage	Width,  A mm	Depth, B mm	Height, C mm
12kV	600, 750, 1000	1350	2200
17,5kV	600, 750, 1000	1350	2200
24kV	750, 1000	1560	2200

12,17.5 Kv Depth (mm) 1350 Height (mm) 2200 Width (mm) 1000 750 600 Weight (kg) 780 930 1050 Rated current (A) 630 1250 1600 2000 2500 3150 IF OF BC BR BRES M MES LBSF* STP*

24 Kv Depth (mm) 1560 Height (mm) 2200 Width (mm) 1000 750 Weight (kg) 1010 1100 Rated current (A) 630 1250 1600 2000 2500 IF OF BC BR BRES M MES LBSF* STP*

*STP and LBSF cubicle maximum ratings are 630A