Neel Electric’s DOS series fully enclosed stainless steel ring main unit – a KEMA certified outdoor RMU – delivers maintenance‑free modularity, corrosion resistance, and internal arc protection (25kA/1s) for reliable power distribution in harsh environments.
The DOS series is a fully enclosed ring main unit (RMU) with a stainless steel enclosure, housing all live parts and primary equipment within a sealed compartment. It is immune to external environmental influences and requires no maintenance. The modular design allows flexible combination of functional units, while the extension busbar adopts fully insulated solid busbars to ensure high reliability and safety. Automation or intelligent solutions are available as options to deliver added value.
· Designed for outdoor applications, the DOS series withstands corrosive atmospheres and intense solar radiation. It offers non-extendable configurations with 2 or 3 units. Pressure relief can be directed either upward or downward, and the internal arc rating reaches 25 kA for 1 second.
· The product holds ASTA, KEMA, and IECEE certifications, meeting both domestic and international market requirements.
|
Parameter |
Value |
|
Rated voltage (kV) |
40.5 |
|
Rated frequency (Hz) |
50/60 |
|
Rated current (A) |
C unit: 630; F unit: 63; V unit: 630 |
|
Rated power-frequency withstand voltage (kV) |
95/118 (across isolating distance) |
|
Rated lightning impulse withstand voltage (kV) |
185/215 (across isolating distance) |
|
Mechanical endurance (Operations) |
C unit: 5000; F unit: 5000; V unit: 10000 |
|
Rated short-circuit breaking current (kA) |
F unit: 31.5; V unit: 20/25 |
|
Rated making current (kA) |
C unit: 50; F unit: 80; V unit: 50/63 |
|
Rated transfer current (A) |
F unit: 1400 |
|
Main circuit rated short-time withstand current |
C and V units: 20 kA for 4 s, 25 kA for 3 s |
|
Main circuit rated short-time withstand current (4 s) |
C and V units: 20 kA (4 s), 25 kA (3 s) |
|
Main circuit rated peak withstand current |
C and V units: 50/63 kA |
|
Internal arc classification |
AFLR, 25 kA, 1 s |
|
Rated working pressure (gauge pressure at 20 °C) |
0.04 MPa |
|
Minimum working pressure (gauge pressure at 20 °C) |
0.03 MPa |
|
Enclosure protection degree |
IP41 |
|
Gas compartment protection degree |
IP67 |
|
Annual gas leakage rate |
≤ 0.01 % |
