Zone and bulk supply substations
Incomer, feeder and bus section switchboards for 11, 22 and 33 kV networks.
Switchgear
MV primary switchgear, air or gas insulated.
Robustly engineered for a very long service life and excellent reliability, with competitive pricing and lead times.
Metal clad medium voltage switchgear from 3.6 to 40.5 kV for zone and bulk supply substations, industrial plants and renewable generation.
Withdrawable air insulated cubicles with vacuum circuit breakers, and gas insulated cubicles in a sealed stainless steel tank, rated up to 4,000 A and 40 kA.
- Voltage class
- 3.6 to 40.5 kV
- Rated current
- 630 to 4,000 A
- SC breaking current
- Up to 40 kA
- Insulation
- Air or SF6 gas
The range
MV primary switchgear is supplied as individually configured cubicles for incomers, feeders, bus sections and metering, matched to your network fault level, busbar rating and protection scheme.
Withdrawable, 3.6 to 12 kV
Handcart vacuum circuit breaker cubicles for 630 A to 4,000 A and fault levels from 20 to 40 kA, in 800 and 1,000 mm wide cubicles. Built for single busbar and sectionalised busbar substations.
Withdrawable, 24 kV
Cubicles rated 630 A to 2,500 A and 20 to 31.5 kA for 11, 22 and 24 kV networks, in 800 and 1,000 mm widths.
Withdrawable, 40.5 kV
Single busbar and sectionalised busbar switchboards for 33 kV networks, rated up to 2,000 A and 31.5 kA, with vacuum or SF6 circuit breakers.
Slim Cubicles for Restricted Switchrooms
Cubicles only 500 mm and 550 mm wide, rated 12 kV, 1,250 A and 31.5 kA, that can be installed against a wall with a single operating aisle at the front, reducing switchroom floor area.
Gas Insulated, 40.5 kV
Circuit breaker and load switch cubicles in a sealed stainless steel gas tank, 500 mm and 450 mm wide, for sites where space, pollution or maintenance access is a constraint.
Digital Monitoring
Optional online monitoring of temperature and arc light, with real time data, risk warning and remote access, for operators who want condition information from the switchboard.
Specifications
Typical ratings for the standard range. Final values are confirmed for each project.
Customised designs available. If your project needs ratings, features, design requirements or arrangements outside the standard range below, we design and manufacture to your requirements and application.
Technical dataMV primary switchgear
| Parameter | Standard | Optional or on request |
|---|---|---|
| Rated voltage | 3.6 to 12 kV, 24 kV and 40.5 kV | |
| Rated frequency | 50 Hz | |
| Rated current | ||
| 3.6 to 12 kV | 630 to 4,000 A | |
| 24 kV | 630 to 2,500 A | |
| 40.5 kV air insulated | 630 to 2,000 A | |
| 40.5 kV gas insulated | 630 A | |
| Short circuit breaking current and short time withstand current (4 seconds) | ||
| 3.6 to 12 kV | 20, 25 or 31.5 kA | 40 kA |
| 24 kV | 20, 25 or 31.5 kA | |
| 40.5 kV air insulated | 20, 25 or 31.5 kA | |
| 40.5 kV gas insulated, circuit breaker | 31.5 kA | |
| 40.5 kV gas insulated, load switch | 25 kA | |
| Peak withstand and making current | 50, 63 or 80 kA | 100 kA (up to 12 kV) |
| Internal arc classification (1 second) | ||
| 3.6 to 12 kV | 40 kA | |
| 24 kV | 31.5 kA | |
| 40.5 kV gas insulated, circuit breaker | 31.5 kA | |
| 40.5 kV gas insulated, load switch | 25 kA | |
| Circuit breaker | Withdrawable vacuum circuit breaker | SF6 circuit breaker (40.5 kV air insulated) |
| Degree of protection | ||
| Air insulated | IP4X enclosure, IP2X compartments | |
| Gas insulated | IP4X enclosure, IP67 gas tank | |
| Cubicle size, 3.6 to 12 kV | ||
| Width | 800 or 1,000 mm | 500 or 550 mm slim cubicle |
| Depth | 1,500 or 1,700 mm | |
| Height | 2,300 mm | |
| Cubicle size, 24 kV | ||
| Width | 1,000 mm | |
| Depth | 1,860 mm | 2,260 mm deep version |
| Height | 2,430 mm | |
| Cubicle size, 40.5 kV air insulated | ||
| Width | 1,400 mm | |
| Depth | 2,800 mm | |
| Height | 2,600 mm | |
| Cubicle size, 40.5 kV gas insulated | ||
| Width, circuit breaker | 500 mm | |
| Width, load switch | 450 mm | |
| Depth | 1,000 mm | |
| Height | 2,200 mm | |
| Gas insulated power frequency withstand voltage | ||
| Phase to phase and to earth | 95 kV | |
| Across open contacts | 118 kV | |
| Gas insulated lightning impulse withstand voltage | ||
| Phase to phase and to earth | 185 kV | |
| Across open contacts | 215 kV | |
| Gas insulated mechanical life | ||
| Circuit breaker | At least 10,000 operations | |
| Load switch | At least 5,000 operations | |
| Earthing switch | At least 3,000 operations | |
| Gas insulated SF6 | ||
| Gauge pressure at 20°C | 0.04 MPa or less | |
| Annual leakage rate | 0.01% or less | |
Design and performance
Air insulated cubicles keep every function in its own compartment, and gas insulated cubicles seal the live parts away from the environment altogether.
Metal Clad Compartments
Circuit breaker, busbar and cable compartments are separated, with IP4X enclosures and IP2X compartments. Cubicles for up to 12 kV have passed internal arc testing, and 24 kV cubicles are classified to 31.5 kA for 1 second.
Corrosion Resistant Construction
Cubicle bodies are folded from aluminium zinc coated steel on CNC machinery, giving strong resistance to corrosion and oxidation, high mechanical strength and low weight.
Slim and Compact Options
Cubicles 500 mm and 550 mm wide reduce switchroom footprint, by up to 60% in the slimmest case, and can be connected directly to high current cubicles for easy extension.
Sealed Gas Insulation
In the gas insulated range all primary live parts sit in a stainless steel tank filled with SF6, unaffected by dust, humidity, pollution and temperature variation. The circuit breaker uses a maintenance free vacuum interrupter, and the load switch uses a low pressure SF6 puffer arc extinguishing principle.
Integrated Isolation and Earthing
Gas insulated cubicles combine an isolating and earthing function with the vacuum circuit breaker, or use a three position load switch, for a compact footprint.
Condition Monitoring
Optional temperature and arc light monitoring, real time data display, risk warning and remote operation through cloud and mobile platforms.
Applications
Delstar supplies primary switchgear for:
Industrial plants and mining
Reliable MV distribution for process loads and large motors, with internal arc protection for people and plant.
Power stations and generation
Station auxiliary supply and generator connection switchgear.
Wind farms and solar generation
Collector and connection switchboards, including gas insulated cubicles for onshore and offshore sites.
Urban and commercial substations
Compact and slim cubicles where switchroom space is limited.
Sourcing and quality assurance
Our primary switchgear is produced in a factory that holds ISO 9001, ISO 14001 and ISO 45001 certification. Sheet metal is CNC punched, laser processed and folded, and surfaces are cleaned, degreased and coated on an automated powder coating line for uniform thickness and strong corrosion protection. Type test reports are available for the range. Delstar delivers to site across New Zealand, Australia and the Pacific.
Lifecycle support
- Specification and configuration: we help select the cubicle arrangement, breaker rating, protection and monitoring for your network.
- Installation and commissioning: see Installation and commissioning.
- Training and demonstration: hands on training or demonstrations at your workshop or facility, provided through our engineering services.
- Spares and asset management: spares and ongoing support through our asset management service.
Talk to our team
Specify your primary switchgear requirement.
Tell us the voltage class, rating, fault level and installation environment, and any customised requirement. We will match the specification to the right configuration, or design and manufacture to suit.