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In medium-voltage distribution systems, вакуумные выключатели play a core role in safety. This is because they can quickly cut off fault currents, thereby preventing equipment damage. However, choosing внутренние вакуумные выключатели или наружные вакуумные выключатели is not a random decision. Selecting the wrong circuit breaker may result in outdoor equipment being unable to withstand wind and rain, leading to frequent maintenance. If indoor models are used outdoors, it will cause space waste and an increase. This blog will introduce the differences between them, application scenarios, and cost performance to help you select the most suitable circuit breaker for your project.
Сайт outdoor vacuum circuit breaker is a power protection device specifically designed for outdoor environments. It uses vacuum as the arc extinguishing medium and has strong arc extinguishing capability and long-term insulation performance. It is different from the indoor models. It has a sturdy casing and a special insulation design. For example, ABB’s OVB series uses a sealed pole housing and is equipped with porcelain or polymer insulators; while Eaton’s NOVAs series uses epoxy resin poles to withstand heavy rain, dust, and extreme temperatures. It is usually installed on utility poles or outdoor platforms and is widely used in medium-voltage power distribution networks, wind and solar power plants, as well as urban and rural power grid renovations.
Сайт indoor vacuum circuit breaker is specifically designed for enclosed spaces such as distribution rooms and switch cabinets. Its key feature lies in its compact structure and high space utilization. Taking the 405 W-VACi series from Aitong as an example, its modular design enables it to fit most mainstream cabinet types, and it has a protection level of IP30, which can prevent accidental contact with live components. Its core advantages are low maintenance costs and stable performance. The vacuum interrupter chamber with epoxy resin encapsulation technology can achieve a maintenance-free period of 5 to 8 years, and the integrated spring charging lever can also ensure safe operation in emergency situations. It is mainly used in industrial parks, large communities, and factories for the high-voltage side of 10-kilovolt transformers, and can meet the power distribution requirements of 315 kilovolts to 2000 kilovolts loads.
Ignoring the differences between внутренние вакуумные выключатели и наружные вакуумные выключатели can lead to significant risks and losses. If you expose the indoor model to moisture and dust, insulation failure and short circuits will occur within a few months; conversely, installing the outdoor model indoors will waste space and increase unnecessary costs. Moreover, outdoor models usually require additional seismic and windproof designs. Whether for EPC partners undertaking infrastructure projects or factory procurement personnel responsible for upgrading power systems, clearly understanding this contrast directly affects construction efficiency, long-term operational stability, and maintenance budgets.
Сайт outdoor vacuum circuit breaker is specifically designed for outdoor use and can adapt to various temperature changes, including rainfall, snowfall, and pollution. Some models even come equipped with hydrophobic HCEP insulators to cope with severely polluted areas. In contrast, the indoor vacuum circuit breaker relies on enclosed spaces such as switch cabinets and requires a dry, dust-free, and temperature-stable environment.
The protection level is a clear boundary. Outdoor circuit breakers usually have a protection level of IP54 or higher, and their sealed enclosures can prevent moisture and dust from entering. ABB’s OVB series even adopts a “lifelong sealed rod” to avoid internal component aging. Вакуумные автоматические выключатели для помещений usually have a protection level of IP30, with the focus being on preventing solid objects with a diameter greater than 2.5 millimeters from entering. Their enclosures are relatively simple, mainly to isolate the live components and prevent operators from accidentally coming into contact.
The initial installation cost of наружные вакуумные выключатели is relatively high because they require support rods, waterproof bases, and sometimes seismic brackets. In contrast, внутренние вакуумные выключатели do not need these accessories, but they require a matching switch cabinet. However, the overall installation cost is still 15% to 25% lower than that of the outdoor models.
The cost of civil buildings has further widened this gap. For наружные вакуумные выключатели, civil projects include the pouring of pole foundations, the excavation of cable trenches, and the construction of grounding grids. Especially in remote rural areas, the transportation and construction costs of materials may account for 40% of the total cost. For внутренние вакуумные выключатели, it is only necessary to ensure that the distribution room meets basic load-bearing and waterproof requirements. If the distribution room already exists, the cost of civil buildings can be almost zero.
Сайт внутренние вакуумные выключатели perform exceptionally well in terms of space utilization. For instance, Eaton’s 405 W-VACi series features a compact structure and can be installed in standard 2.2-meter-high switch cabinets, which is highly suitable for distribution rooms in urban buildings with limited space. Вакуумные автоматические выключатели наружной установки, on the other hand, require a larger installation area. Their pole-mounted design necessitates maintaining a safe distance from surrounding objects, which is not suitable for densely populated urban areas.
For large-scale outdoor projects such as wind power plants, solar power stations, and rural power grid upgrading projects, наружные вакуумные выключатели should be selected. This is because their rainproof performance can ensure stable operation in open areas. While for indoor projects such as industrial parks, shopping centers, and high-rise residential buildings, внутренние вакуумные выключатели are more suitable. Their low-maintenance features can reduce the workload of on-site staff.
If the circuit breaker needs to be switched frequently, then an indoor vacuum circuit breaker would be more suitable. Its spring mechanism can operate up to 10,000 times, and the enclosed environment can reduce the wear on the moving parts. While the outdoor vacuum circuit breaker is more suitable for scenarios with lower switching frequencies, as frequent operations may cause dust to enter the mechanism and affect its performance.
Вакуумные автоматические выключатели наружной установки have strong environmental adaptability and can operate normally in high-altitude areas and humid coastal regions. In contrast, внутренние вакуумные выключатели are more sensitive to the environment. High humidity may cause condensation on the insulator surface, leading to arcing. Besides, high temperatures may reduce the arc-extinguishing performance of the vacuum circuit breaker, so it must rely on the ventilation and air conditioning systems of the distribution room to maintain normal operation.
Сайт indoor vacuum circuit breaker offers greater project flexibility. It supports “plug-and-play” accessories and can quickly add current transformers or voltage transformers based on subsequent requirements. This makes system upgrades very convenient. The outdoor vacuum circuit breaker, on the other hand, has fixed mounting accessories. Changing the configuration requires on-site modifications, which are both time-consuming and labor-intensive, and may also affect the waterproof performance of the enclosure.
From a 10-year lifecycle perspective, внутренние вакуумные выключатели offer greater cost-effectiveness. Their maintenance costs are 60% lower than those of outdoor models, and there is no need to replace the rainproof components regularly. In contrast, the long-term cost of наружные вакуумные выключатели is higher. Annual inspections require cleaning the insulators, lubricating the mechanical devices, and testing the waterproof performance. Even in severely polluted areas, the replacement cycle of the insulators is only 5 to 6 years.
For buyers, the core of choosing these two products lies in balancing the aspects of “environment, cost, and demand”. If the project is outdoor-oriented, has high environmental requirements, and can withstand a higher initial cost, then the outdoor vacuum circuit breaker is the preferred choice; if the project is indoor-oriented, focuses on space saving and low maintenance costs, and has a limited budget, then the indoor vacuum circuit breaker is more suitable. At the same time, you also need to pay attention to the key parameters. The outdoor model emphasizes rated voltage and weather resistance, while the indoor model focuses on rated current and cabinet compatibility. It should be noted that the outdoor model can be used indoors,s but the indoor model definitely cannot be used outdoors.
These two types of maintenance strategies differ significantly. For наружные вакуумные выключатели, the monthly inspection should focus on the cleanliness of the insulator and the waterproofing of the enclosure; for внутренние вакуумные выключатели, the emphasis is on the environment of the switch cabinet. Both types require a short-circuit current test every 3 to 5 years to ensure the arc-extinguishing performance of the vacuum interrupter chamber.
Вакуумные автоматические выключатели наружной установки are indispensable in outdoor environments. They are the core equipment of wind and solar power plants, the “pillar” of rural distribution networks, and a key component of box-type substations. In contrast, внутренние вакуумные выключатели dominate indoor environments: they protect the power supply of industrial parks, ensure the safety of large shopping centers, and support the stable operation of high-rise residential buildings.
In a rural power distribution network upgrade project in northern China, the original oil-immersed circuit breakers frequently malfunctioned due to low temperatures (the lowest temperature in winter was -30℃). The project team replaced them with the ZW32-12L outdoor vacuum circuit breaker. This model uses special lubricants and cold-resistant insulating materials, and can start normally at -40℃. After one year of operation, the failure rate dropped from 15% to 0.5%, and the maintenance cost was reduced by 60% compared to the original equipment. At the same time, it is equipped with an intelligent controller, which can achieve remote fault location, significantly saving the time for maintenance personnel to travel to remote villages.
A newly-built electronic industrial park in eastern China has strict requirements for power supply stability and space utilization. This project selected Eaton’s 405 W-VACi series внутренние вакуумные выключатели and installed them in standard switch cabinets. The compact design of this circuit breaker reduced the area of the distribution room by 30%, saving rental costs for the park. This circuit breaker not only meets the daily usage needs but also reduces the workload of the power department in the park. It only requires remote monitoring monthly, and no on-site inspections are needed.
When choosing between внутренние вакуумные выключатели и outdoor vacuum circuit breakers, it is not a simple “indoor or outdoor” decision. It is a comprehensive judgment based on the project environment, cost budget, operational requirements, and long-term maintenance. Each type has its unique advantages. When making a choice, you should not only consider the initial cost but also calculate the long-term life cycle cost and match the equipment characteristics with the actual needs of the project.
If you are still unsure about whether to choose an indoor vacuum circuit breaker or an outdoor vacuum circuit breaker, or want to learn more about Чуаньли‘s product specifications and customized solutions, please contact us immediately. Our professional team will provide you with a one-stop power protection solution to ensure the safety, stability, and efficiency of your power system!
Q1: Can indoor vacuum circuit breakers be used in outdoor environments in emergency situations?
A1: No. The protection level of внутренние вакуумные выключатели is low, and they lacka rainproof design. Using them outdoors will allow moisture and dust to enter the internal components, and even potentially cause safety accidents. For outdoor emergency situations, you should choose a portable outdoor vacuum circuit breaker (such as the portable outdoor model from Чуаньли) to use.
Q2: What are the differences in service life between наружные вакуумные выключатели and indoor vacuum circuit breakers?
A2: Under normal maintenance conditions, the designed service life of both is 15 to 20 years, but the actual service life will be affected by the environment. The service life of внутренние вакуумные выключатели is more stable. Their enclosed environment reduces component wear, and vacuum circuit breakers can maintain performance for a long time. However, the service life of наружные вакуумные выключатели may be shortened due to harsh environmental conditions.
Q3: How to select the rated current of vacuum circuit breakers for industrial parks?
A3: First, calculate the total load current of the industrial park: for example, if the total power of the park is 5000 kilovolt-amperes and the voltage is 10 kilovolts, then the rated current is approximately 288 amperes. Then, choose a circuit breaker with a rated current that is 1.2 to 1.5 times the calculated current to reserve space for load growth. For indoor use, you can choose an indoor vacuum circuit breaker with a rated current of 630 amperes. For outdoor use, a vacuum circuit breaker with the same rated current is suitable.
Q4: Does Chuanli provide after-sales maintenance services for outdoor vacuum circuit breakers?
A4: Да. Чуаньли provides full lifecycle after-sales guarantee services for наружные вакуумные выключатели. It dispatches technicians to conduct on-site installation guidance during the project commissioning stage, and also provides regular maintenance services during the operation stage. In addition, it offers free technical training for users’ maintenance personnel to help improve the daily management level of the equipment.
