NAREW
NAREW non-compartmentalised switchgears are intended for take-up and distribution of three-phase AC electricity at a rated voltage of up to 17.5 kV and frequency of 50 Hz in industrial and large-scale power distribution networks.
Thanks to extremely compact sizes, the NAREW switchgear units can be installed in new or refurbished power engineering projects which lack the space for many panels or for extension of existing switchgear systems.
The NAREW system of MV non-compartment switchgear units was awarded the Silver Medal of Polskie Sieci Energetyczne during the Energetab exhibition in Bielsko-Biała, Poland.
Advantages of switchgear NAREW:
- high safety of operation ensured by:
- mechanical and electrical interlock system, which prevent erroneous switching operations when using the switchgear
- executing all switching operations with the doors closed
- signaling voltage presence in the main circuit
- structural design protecting from internal arc effects
- use of insulation plate in version with fixed C.B.
- compact overall dimensions,
- simple operation and maintenance thanks to easy access to switchgear and connections
- incorporation of the state-of-the-art switchgear ensuring performance reliability of the switchgear
- different switchgears configurations are possible by setting up modules of various functions
- high resistance to corrosion
Application and features of the system
Medium Voltage switchgears NAREW are designed for operation in 50/60 Hz AC power distribution networks and rated voltages up to 17,5 kV.
The NAREW switchgear units were tested at the Institute of Electrical Engineering (IEL) in Warsaw and certified for compliance to prove the ratings and approve for applications in power engineering facilities, power generating plants, industrial settings, and other establishments which generate, transmit, or consume electricity.
The NAREW switchgear units can be installed in:
- step-down substations
- pad mounted transformers
- switchgear solutions for auxiliary consumption
Medium Voltage switchgear NAREW are:
- metal-enclosed
- indoor
- available with fixed circuit breaker or withdrawable circuit breaker
- with a separated bus-bar system (in truck-mounted design)
- arc-proof
- modular design
- with air insulation
- with single bus-bar system
- equipped with modern switching apparatus
Technical data and certificates
Technical data of switchgear NAREW
| Rated insulation voltage | kV | 12 | 17,5 |
|---|---|---|---|
| Rated lightning impulse withstand voltage (1,2/50μs) | kV | 75/85 | 95/110 |
| Rated power frequency withstand voltage | kV | 28/32 42/48* | 38/45 |
| Rated frequency | Hz | 50 | |
| Rated continuous current of busbars | A | up to 1250A | |
| Rated short time withstand current | kA | up to 25/3s | |
| Rated peak withstand current | kA | up to 63 | |
| Withstand for internal arcing fault | kA | 25/1s | |
| Degree of protection | IP 4X | ||
| IAC classification (class of resistance to internal arc) | AFLR | ||
| PM/PI classification (class of partitions) | PM | ||
| LSC classification (class of compartment accessibility) | LSC2A, LSC2 | ||
| Weight of a single switchgear cubicle | kg | 350 - 900 | |
| Busbar system | single | ||
| Overall dimensions (width)** | mm | 600 - 750 | |
| Overall dimensions (depth)** | mm | 1000 - 1085 | |
| Overall dimensions (height)** | mm | 2000 - 2075 | |
* - required according to ΓOCT
** - without external guards, covers, doors
Environmental operating conditions
Switchgear NAREW with installed switchgear are adapted for indoor operation under normal conditions, with the following environmental conditions:
| Installation altitude above sea level | up to 1000 m | |
|---|---|---|
| Ambient temperature: | peak short-time | 313 K (+40°C) |
| maximum daily average | 308 K (+35°C) | |
| maximum yearly average | 293 K (+20°C) | |
| minimum sustained | 268 K (-5°C) | |
| Air relative humidity at 313 K (+40°C): | during the start up | max. 80% |
| during standstill or operation | max. 95% | |
Certificates
The NAREW switchgear units were tested at the Institute of Electrical Engineering (IEL) in Warsaw and certified for compliance to prove the ratings and approve for applications in power engineering facilities, power generating plants, industrial settings, and other establishments which generate, transmit, or consume electricity.