Coastal distribution networks face severe erosion from sea fog and salt particles, leading to equipment corrosion and insulation aging. Ordinary switchgear cannot adapt to such harsh conditions. Чуаньли develops an outdoor vacuum circuit breaker with professional salt fog resistance and a multi-layer anti-corrosion coating. This article analyzes corrosion risks and product strengths to offer selection guidelines for coastal power projects.
Salt fog contains a large amount of chloride ions; once attached to the metal brackets of electrical equipment, operating transmission parts, and copper and aluminum conductive parts, it will form a conductive electrolyte film with water vapor in the air, quickly triggering electrochemical corrosion. The long-term rust and perforation of the metal surface and the corrosion of the conductive terminal lead to a sharp increase in contact resistance, causing local overheating, burning, and even wire breakage, seriously threatening the reliability of power supply in coastal distribution networks.
Salt crystals deposit on the surface of insulating sleeves and solid insulators, forming conductive creep channels in humid weather; Ordinary epoxy resin insulation is weak in salt spray performance, and the long-term accumulation of salt will cause the surface leakage current to surge, and the surface flashover discharge will occur on foggy and rainy days, accelerating the aging and breakdown of insulation, causing frequent tripping of distribution line switches.
The temperature difference between day and night along the coast is significant, and the equipment heats up quickly during the day, causing salt to adhere, and the temperature drops at night, causing condensation to form inside the cabinet, which dissolves the salt and penetrates into the crevices of the components, causing continuous corrosion of the internal structure and secondary control circuit, forming a vicious cycle of salt fog deposition, condensation, and corrosion.
The indoor vacuum circuit breaker has a low protection grade and is only equipped with ordinary single-layer anti-rust paint. There is no special anti-corrosion coating, which cannot block the invasion of external salt fog and condensation water. After being put into operation in coastal areas for 1-2 years, the internal structure will rust extensively and the insulation creep will be serious, requiring frequent replacement of accessories or even the entire equipment, which will bring high operation and maintenance costs and power outages to the coastal power grid.
Chuanli provides two sets of anti-corrosion metal configurations for coastal projects, suitable for different salt spray concentration requirements: Scheme 1 uses 304 stainless steel cabinets and all metal structural components, naturally resistant to chlorine ion corrosion, no need for additional coating; Option 2: carbon steel base material, whole machine Dacromet pre-treatment + thick epoxy anti-corrosion double-layer spraying process, neutral salt spray test duration of more than 1000 hours, far exceeding the industry standard of 500 hours for ordinary circuit breakers. All conductive copper parts are silver-plated and passivated to prevent terminal corrosion and increase contact resistance in salt-spray environments.
Chuanli ZW series outdoor vacuum circuit breaker operation box, the overall protection level of the pole is IP65, the cabinet door and the inlet and outlet holes are all equipped with double-layer three-dimensional ethylene rubber sealing strips, and the bottom of the cabinet is equipped with a breathable anti-condensation valve. The fully enclosed structure can completely block the intrusion of salt mist, rainwater, and dust into the internal mechanism, cut off the source of chlorine ion corrosion from the outside, and fundamentally avoid the attachment of salt mist to the metal and insulating parts inside the cabinet.
All of the outdoor circuit breakers of Chuanli use large climbing distance silicone rubber umbrella skirt insulating sleeve, which has the characteristics of water drainage and self-cleaning, and the salt crystal is not easy to adhere to the surface, and can withstand 70kV lightning impulse voltage; The built-in current and voltage transformers use integral epoxy solid insulation, which is not easy to form a creepage channel in the long-term accumulation of salt, and completely solves the insulation flashover hazard in the coastal high humidity and salt fog working conditions.
All the springs and linkage components in the cabinet are made of a galvanized + passivation composite anti-corrosion process; The secondary wiring terminal is selected as a nickel-plated corrosion-resistant terminal, and the cabinet space can be equipped with a constant-temperature dehumidification heater. When the humidity exceeds the standard, the heater will automatically start to eliminate condensation water to avoid saltwater corrosion of the secondary circuit, ensuring the protection and remote signal transmission module can operate stably in a long-term salt spray environment.
| Coastal Application Scenarios | Salt Spray Corrosion Class | Recommended Product Models | Anti-Corrosion Configuration |
| Offshore High-Salinity Areas (Offshore Wind Farms, Island Substations) | Severe Salt Spray (C4) | ZW32-24 / ZW□-40.5 Vacuum Circuit Breaker | 304 Stainless Steel Enclosure + Silicone Rubber Bushings (Extended Creepage Distance) + Built-in Dehumidifying Heater |
| Near-shore Industrial Parks (Moderate Salinity) | Moderate Salt Spray (C3) | ZW32-12 Вакуумный автоматический выключатель для наружной установки | Carbon Steel with Dacromet + Dual-Layer Epoxy Anti-Corrosion Coating; IP65 Standard Sealing |
| Remote Island Microgrid Power Supply | Continuous Long-term Salt Spray Exposure | ZW32 Integrated Intelligent Recloser | Comprehensive Anti-Corrosion Mechanism + Salt-Spray-Resistant FTU Control Terminal |
| Coastal Urban Overhead Lines | Mild Salt Spray (C2) | Standard ZW32 Pole-Mounted Outdoor Circuit Breaker | Standard Anti-Rust Coating + Silicone Rubber Insulation Components |
Stainless steel cabinet products must be selected for C4 severe corrosive environments such as offshore wind farms to avoid coating peeling and metal corrosion caused by long-term seawater erosion. The island equipment has been unattended for a long time, and it needs to be equipped with dehumidification, heating, and fully corrosion-resistant secondary terminals to reduce the frequency of corrosion faults and on-site repairs.
Offshore wind power and offshore substations belong to the high-salt fog C4 severe corrosion environment all year round, and the ZW32-40.5 high-voltage outdoor vacuum circuit breaker from Chuanli should be preferred. The whole machine is made of a 304 stainless steel shell, with a large-diameter silicone rubber insulating sleeve, and an optional built-in thermostatic dehumidification heater can be installed. The entire stainless steel structure avoids the risk of coating aging and falling off due to long-term sea wind erosion, and the dehumidification device eliminates condensation in the cabinet, preventing saltwater corrosion of the operating mechanism.
The coastal chemical industry and port industrial park belong to the C3 moderate salt spray environment, and the outdoor vacuum circuit breaker ZW32- 12 with carbon steel double anti-corrosion coating is the most cost-effective. The cabinet body is pre-treated with Dacron + thick epoxy anti-corrosion spraying, which can pass the 1000-hour neutral salt spray test. The standard IP65 sealing structure blocks the daily salt spray intrusion, meeting the stable operation requirements of industrial distribution overhead lines.
Island power supply equipment is far away from the operation and maintenance site and is unattended all year round. Continuously suffering from the erosion of sea salt fog, matching with the ZW32 integrated intelligent circuit breaker, integrating the FTU anti-salt fog control terminal, all internal transmission mechanisms are treated with composite anti-corrosion treatment, the cabinet is equipped with an automatic temperature control heating component, and the frequency of on-site maintenance caused by corrosion faults is minimized.
The overhead power lines for coastal residents in urban areas are in a C2 light salt spray environment, with a relatively low salt spray concentration. Standard ZW32-12 pole-mounted outdoor vacuum circuit breakers with standard anti-rust coating and silicone rubber insulating sleeves can be selected, which balance corrosion resistance and procurement cost and are suitable for daily power distribution operations in urban coastal communities.
| Comparison Item | Chuanli ZW Series Outdoor Vacuum Circuit Breaker | Standard Indoor Vacuum Circuit Breaker |
| Salt Mist Sealing Capability | IP65 fully enclosed design; completely blocks salt mist intrusion | IP30 low protection rating; salt mist easily penetrates the enclosure |
| Anti-corrosion Coating Standard | Optional stainless steel or dual-layer epoxy high-corrosion-resistance configuration;> 1000 h salt spray test rating | Single-layer standard anti-rust paint; salt spray resistance of only 200 hours |
| Condensation Control Capability | Breather valve + optional dehumidifier; automatically eliminates internal condensation | No humidity control structure; significant water accumulation and condensation in humid weather |
| Theoretical service life in coastal areas | Up to 12–18 years, depending on the anti-corrosion grade | Only 2–4 years; severe corrosion after 3 years |
| Insulation and salt-spray resistance | Silicone rubber with large-creepage sheds; self-cleaning and salt-accumulation resistant | Standard epoxy; highly susceptible to tracking and flashover |
The core gap between the two types of equipment is concentrated in the special design of sealing and anti-corrosion for salt spray, and indoor circuit breakers are only suitable for indoor closed clean rooms. Once used in coastal open-air overhead lines, corrosion hazards will occur frequently and replacement costs will be high in the short term. It is not recommended to use coastal distribution network projects at all.
Chuanli outdoor circuit breaker whole machine IP65 sealed cabinet body, all gaps equipped with multi-layer rubber sealing structure, can completely isolate external salt spray, rainwater into the cavity; The indoor vacuum circuit breaker only has IP30 protection, the cabinet door and the input and output lines are not completely sealed, the salt particles carried by the sea wind continue to penetrate into the equipment continuously with the airflow, and the metal parts continue to corrode.
The outdoor model supports two high-end solutions of stainless steel and double corrosion protection, and the salt spray test cycle is far beyond the industry standard. The indoor circuit breaker surface is only sprayed with a thin layer of ordinary anti-rust paint, which is very easy to fall off in a high-humidity environment with high salt spray, and the base material will rust quickly after exposure.
The outdoor cabinet is equipped with a breathable balance valve to reduce the temperature difference between the inside and outside, and can be equipped with an internal dehumidification heater to automatically remove condensation water, avoiding the formation of salt water film in the cabinet; There is no humidity control structure in the indoor cabinet, and a large amount of condensation accumulates at night along the coast, accelerating the electrochemical corrosion of metal.
For different salt spray concentrations, the outdoor vacuum circuit breaker can operate stably for more than 12 years without the need for large-scale replacement of components; The indoor circuit breaker will be seriously corroded and the insulation will deteriorate within 2-4 years after being put into operation along the coast, requiring frequent overhaul and replacement, which will increase the operation and maintenance expenses of the power grid enterprises for a long time.
Conventional breakers are vulnerable in a salt fog environment. Chuanli’s outdoor vacuum circuit breaker forms a complete anti-corrosion system and delivers reliable salt fog resistance for all types of coastal distribution networks. Choose professional anti-corrosion equipment to reduce maintenance work and guarantee the table’s power supply.
Q1: What kind of anti-corrosion material is used in the cabinet of the Chuanli outdoor vacuum circuit breaker for coastal projects?
A1: Optional 304 stainless steel cabinet, or ordinary carbon steel whole machine Dacro treatment + epoxy anti-corrosion double coating.
Q2: What is the protection level of the cabinet of the outdoor ZW32 circuit breaker from Chuanli, and can it block salt spray?
A2: The entire control box has an IP65 sealing grade, blocking salt fog, dust, and rainwater from entering.
Q3: What specific optimizations have been made for insulating components in coastal salt-spray environments?
A3: Use silicone rubber high-climbing-distance tubing and epoxy solid insulation current voltage transformer.
Q4: Can a dehumidification heater be added to the Chuanli outdoor circuit breaker to adapt to the high-humidity environment along the coast?
A4: Supports an optional built-in thermostatic heater to eliminate condensation and water accumulation in the cabinet.
Q5: Why can’t indoor vacuum circuit breakers be used in coastal salt fog grids?
A5: The indoor circuit breaker has a low protection level and no special anti-salt fog anti-corrosion coating, which makes it very easy to corrode and cause insulation failure.
