38kV Three‑Phase Mechanical‑Electronic Sectionalizer
Key attributes
| Brand | Rw Energy |
| Series | RDK |
| Rated voltage | 38kV |
| Rated frequency | 60 Hz / 50 Hz (Selectable) |
| Rated continuous current | 100A/200A/300A |
| Pickup (programmable) | 16–480 A（7 gears） |
| Current accuracy | ±5% |
Description
Introduction:
The RDK-38/300, developed by Zhejiang RockwEll Energy for domestic and overseas 38 kV, 50/60 Hz distribution systems, coordinates with reclosers or autoreclosing breakers to confine outages to the faulted segment . Because it distinguishes transient from permanent faults by counting fault-current events, it acts only on permanent faults — transient faults reset automatically after the programmable memory time (30–300 s) (p.3). Because its electronic controller is powered by line-current induction instead of an external auxiliary supply, it needs no PT, no batteries and no routine maintenance — main-circuit resistance ≤300 μΩ, current measurement accuracy ±5% .
Key Technical Data:
| Parameter | Value |
| Rated voltag | 38 kV |
| Rated frequency | 60 Hz / 50 Hz (Selectable) |
| Rated continuous current | 100A/200A/300 A |
| Minimum line current | 10 A |
| Current accuracy | ±5% |
| Main-circuit resistance | ≤300 μΩ |
| Pickup (programmable) | 16–480 A（7 gears） |
| Counts (programmable) | 1 / 2 / 3 / 4 |
| Reset (memory) time | 30–300 s（ 1 s） |
| Ambient temperature | -40 ℃ ~ +60 ℃ |
| Altitude / Wind pressure | ≤2,000 m / ≤700 Pa |
| USB port | IP68 |
| Event log | 100 records, Excel export |
Application Scenarios:
1.On long main lines with multiple branches, faults risk tripping the substation breaker and blacking out the whole feeder. Installed at branch/segment points, the RDK-15/300 resets automatically on transient faults and drops out load-free on permanent ones, isolating only the faulted branch .
2.With a 1-fast-3-slow substation recloser and sectionalizers set F1=3, F2/F3/F5=2, F4/F6=1 counts, any of 7 line segments is isolated on fault and the recloser restores the other six
3.Requiring no communication channel and no external supply, it fits remote lines without 4G or a master station, supporting local (non-communication) feeder automation
Application Logic:
1.After closing by hookstick, counting starts once line current exceeds pickup .
2.When the upstream recloser trips and the line de-energizes — because the sectionalizer drops out only when load-free, its contacts fall safely to create a visible isolation gap.
3.After the programmed counts (1–4), the controller energizes the mechanism coil, releasing the pre-charged detent; the section drops out and the recloser restores healthy sections .
4.Transient faults never reach the count threshold — because the counter resets after the memory time (30–300 s), no crew visit is needed.
Production Workshop:
Solutions for Sectionalizer
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Communication-Free Feeder Automation: Recloser and Drop-Out Sectionalizer Coordination for Grids Without Communication InfrastructureTarget markets: Africa · Southeast Asia · South America · South Asia | Products: recloser + drop-out sectionalizerDistribution Reliability Challenges in Communication-Constrained NetworksIn Nigeria, a rural distribution feeder trips an average of 8 times per month [source to be confirmed]. Each outage — from the moment the substation protection operates until supply is restored — typically lasts 2 to 5 hours, and overnight outages and outages during the rainy season are routine.When a fault occu -
Distribution Automation — The Evolution from Reactive Repair to Active Self-Healing Smart Grids1. Industry Challenge: The "Physical Blind Spots" of Traditional Distribution Networks1.1 The "Manual Search" Era of Fault LocationIn traditional distribution networks, when a 10kV feeder trips, maintenance crews must patrolkilometers of line pole-by-poleto visually locate the fault point. This outdated operational model directly results in three critical consequences:Degraded SAIDI Metrics: Average outage durations typically exceed 120 minutes.Wildfire Risk: High-impedance ground faults (e.g., -
Coordinated Application Scheme for Reclosers and Drop-Out Type Sectionalizers1. Executive SummaryThis solution proposes a fault-isolation architecture based on the coordinated operation of automatic reclosers and drop-type sectionalizers, featuring “local control without communication.” It is particularly suited for rural and suburban feeders in 15 kV overhead distribution networks in developing countries and regions overseas—areas where SCADA infrastructure is weak, communication maintenance costs are high, and enhancing power supply reliability is the primary objective
