RELF 2S - Double busbar medium voltage switchgear

The page presents RELF 2S type medium voltage switchgear:

air insulated,
metal-clad,
withdrawable,
double busbar,
with rated voltage 12 kV,
for indoor use.

RELF 2S is a modular, withdrawable, metal-clad, air insulated switchgear for primary distribution. It was equipped with double busbar system, which enable the creation of state of the art, complex supplying systems in distribution stations for industry and for generation and distribution sector. The use of interlocks system and an arc-proof design ensures highest possible operational safety and switchgear maintenance. It is intended for operation in normal conditions, as specified by the (PN-EN) IEC 62271-1 standard.

Types of bays

The switchgear may be composed of various functional units:

feeder bays with a circuit breaker and with optional voltage measurement,
transverse bus coupler bay,
longitudinal, double cubicle bus coupler bay with a circuit breaker and sectionalizer,
metering bay,
feeder bay with switch disconnector.

The withdrawable module of the switchgear may be equipped with a circuit breaker, contactor, sectionalizer, set of fused voltage transformers. It may be placed in the positions of: service, test/disconnection and separation.

Characteristics and advantages

Main advantages

visual inspection of the state of switches - disconnectors, circuit breaker and earthing switch
doors in the rear of the switchgear - excellent access to cables and instrument transformers
removable inspection plates - easy access to disconnectors
advanced gas blow-out system - specially designed pressure relief duct discharges pressure from inside the bay
optional gas exhausting duct - discharges gases outside of the switching room
remote control - optional electrical drives for all switches
possibility of equipping with current and voltage sensors
bay with a fused switch disconnector - auxiliary transformer feeder

Characteristic features

air insulated,
frame-less, self-supporting design constructed with zinc-coated riveted steel sheets,
double busbar system,
IAC AFLR internal arc classification,
interlocks and protections against performing incorrect switching operations,
free-standing with access to cable connections from the rear of the cabinet,
ease of operation,
versions with manual drives or electrical drives of main switches and withdrawable module are available, depending on requirements and configuration of switchgear bays,
high operational safety.

The switchgear is designed in a manner that ensures that normal operation, inspections and maintenance operations may be performed in a safe manner.

High operational safety is achieved through:

internal arc resistance of the switchgear enclosure,
interlocks between switching operations and opening of doors,
racking the withdrawable module with doors closed,
controlling the switches remotely or locally,
the use of internal compartments and partitions,
the possibility of visual control of switching operations through inspection windows,
bay voltage indication system.

Basic technical data

Compliance with standards:

The RELF 2S type switchgear meets the requirements of the following standards:

(PN-EN) IEC 62271-1 - “High-voltage switchgear and controlgear. Common specifications”,
(PN-EN) IEC 62271-200 - “High-voltage switchgear and controlgear. AC metal-enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV”,

The switchgear is certified by appropriate accredited bodies.

Basic technical data
PARAMETERS		TYPE
		RELF 2S
Rated voltage	[kV]	12
Main busbars and incoming feeder rated continuous current	[A]	630		1250	1600	2000	2500
Rated power-frequency withstand voltage	[kV]	28
Rated lightning impulse withstand voltage	[kV]	75
Rated frequency	[Hz]	50
Rated short-time withstand current	[kA/3s]	31,5
Rated peak withstand current	[kA]	80
Withstand for internal arcing fault	[kA/1s]	31,5
Degree of protection		up to IP4X
Cubicle width	[mm]	650	800¹⁾	800 (650)	800	1100	1100
Cubicle height	[mm]	2700²⁾
Cubicle depth	[mm]	1800
Compliance with standards	(PN-EN) IEC 62271-200; (PN-EN) IEC 62271-1; (PN-EN) IEC 60529
¹⁾ Width of bay with a switch disconnector ²⁾ Height of the cubicle without the gas exhausting “I” (gas exhausting duct as optional equipment)

Design

The RELF 2S switchgear bay is designed as a cubicle with separate functional compartments:

Functional compartments of a feeder bay with circuit breaker:

busbar compartment of system I
busbar compartment of system II
disconnector compartment of system I
disconnector compartment of system II
internal pressure relief and blow-out duct
auxiliary circuits LV compartment
main device compartment
cable compartment
gas exhausting duct (optional)

Feeder bay with a circuit breaker (option with voltage measurement)

Longitudinal bus coupler bay with circuit breaker

Transverse bus coupler bay

Longitudinal coupler bay with sectionalizer

Metering bay – SYSTEM I and II

Metering bay – SYSTEM II

Metering bay – SYSTEM I

Bay with switch disconnector

Designations of devices used in the switchgear bays
Q1	circuit breaker
Q2	switch disconnector
Q3	earthing switch
Q4	sectionalizer
Q5	disconnector
F	fuse link
T1	current transformer
T2	voltage transformer
H	voltage indicator

Other types of bays on arrangement with the manufacturer.
Bay equipment may be adapted to special requirements on arrangement with the manufacturer.