Load-Break Drop-Out Fuse Cutouts
Arc Chute + Auxiliary Contacts – Safe Load Switching with Hot-Stick
Load-break cutouts add an auxiliary arc-extinguishing chamber so operators can safely switch rated load current with an insulated hot-stick — no separate disconnect switch needed. Fuse link still protects against faults.
OEM / ODM – Low-MOQ samples – Type-test reports
Overview
A standard fuse cutout can only interrupt fault current — the fuse link melts and the arc is quenched by the tube liner. If an operator tries to open a standard cutout under load, the arc drawn between the separating contacts has no controlled path and can cause a dangerous flashover.
The load-break cutout solves this by adding a secondary set of auxiliary (arcing) contacts housed inside a sealed arc-extinguishing chamber mounted beside the main fuse tube. When the operator pulls with the hot-stick:
- Main contacts remain closed — current still flows through the primary path
- Auxiliary contacts separate first inside the arc chute, drawing the arc into a narrow gap
- Arc chute liner decomposes into high-pressure gas, blasting and lengthening the arc
- Arc extinguishes at current zero — the switch then continues to the fully open position
This three-stage sequence (main contacts hold > auxiliary contacts break > arc chute extinguishes) is the same principle used in MV load-break switches. The cutout then serves double duty: fault protection via fuse link and load switching via arc chute — eliminating the cost and pole space of a separate disconnect switch.
Technical Specifications
| Rated Voltage | 10-38 kV |
|---|---|
| Rated Current | 100 A / 200 A |
| Load-Break Capacity | Up to rated continuous current |
| Fault Breaking Capacity | 6.3-12.5 kA (via fuse link) |
| Arc Chute Type | Enclosed, gas-evolving liner material |
| Auxiliary Contact Material | Copper-tungsten alloy (arc-resistant) |
| Main Contact Material | Copper alloy, silver-plated |
| Operating Method | Insulated hot-stick, single pull action |
| Mechanical Life | >=500 load-break operations |
| Insulator Options | Porcelain or Polymer |
| Standards | IEC 60282-2, GB 15166, IEEE C37.42 |
Range
| Model | Voltage | Current | Insulator | Load-Break |
|---|---|---|---|---|
| FSC-12/100L | 12 kV | 100 A | Polymer/Porcelain | Yes |
| FSC-12/200L | 12 kV | 200 A | Polymer/Porcelain | Yes |
| FSC-24/200L | 24 kV | 200 A | Polymer/Porcelain | Yes |
| FSC-36/100L | 36 kV | 100 A | Polymer/Porcelain | Yes |
Also available with disconnect blade for visible isolation when open. Custom voltage/current on request.
Key Features
Switch rated load current with a standard hot-stick — no arc flash risk, no special PPE beyond standard lineman gear.
Fuse protection + load switching in one unit saves pole space and eliminates a separate disconnect switch installation.
Auxiliary contacts use Cu-W alloy that resists arc erosion over 500+ operations. Main silver-plated contacts carry continuous current without degradation.
Operator pulls once with hot-stick: main contacts hold, auxiliary contacts break with arc chute, then main contacts separate. No multi-step sequence to remember.
After load-break opening, the tube drops to the open position providing the same visible isolation gap as a standard cutout.
Standard K, T, and H-type links fit in the same tube. Overload bimetal links (F-type) can be combined with load-break for dual-element + load switching.
Applications
Line sectionalizing and reconfiguration under load without de-energizing the entire feeder.
Safely disconnect a transformer for maintenance while it is still carrying load — no need to coordinate an upstream breaker trip.
Switch capacitor banks on and off under load for voltage control and power factor correction.
Open/close ring-main loops under load for fault isolation and network reconfiguration without customer interruption.
Frequently Asked Questions
What is the difference between load-break and standard cutout?
How many load-break operations before maintenance?
Can I retrofit a standard cutout to load-break?
Does load-break affect fault interruption rating?
Need Load-Break Cutouts for Network Switching?
Specify voltage, load current, and switching frequency — we quote within 24 hours.
Request a Quote
Send your requirement, model or drawing — we reply within 24 hours.
Thank You!
Your inquiry has been received.
We'll reply with a detailed quote within 24 hours.