Static transfer switch price

Types of Static Transfer Switches

Static transfer switches (STS) are critical components used to ensure the continuity of power supply to sensitive electrical loads by enabling fast transfer between two redundant power sources. Those power sources can be alternating current (AC) sources coming from various options like utility grids, generators, UPS (uninterruptible power supply) systems, or other transformer-based systems.

Static Transfer Switches can be classified based on a couple of factors.

• Switching Mechanisms

• Number of Poles

• Transfer Time

• Configuration

• Switching Capacity

Static Transfer Switches by Switching Mechanisms

STS with electronic controls is the most common type. It uses microprocessor-based control systems and electronic circuits to monitor inputs continuously and control the switching process. Typically, an electronic static transfer switch has a dual supply-inverted priority scheme. If the primary supply begins to fall below the acceptable threshold or some other predetermined conditions, the load will be automatically transferred to the secondary power supply through an electronic switch.

Electromechanical static transfer switches incorporate electronic controls and electromechanical relays. Like the electronic STS, the electromechanical STS also uses a microprocessor to monitor power sources and control switching. However, it relies on relays driven by certain mechanisms to carry out the switching actions.

Static Transfer Switches by Number of Poles

An STS can also be classified as a single-pole or multi-pole device depending on its structures.

Single-pole static transfer switches are designed to handle single-phase AC power. It has one switching pole that is sufficient to control the flow of electric current for single-phase systems. In contrast, multi-pole static transfer switches are more suitable for three-phase systems. They have multiple switching poles corresponding to the three phases. Three-phase electric power systems usually have four common phases: three active phases designated as separate colors and an implicit neutral phase. The neutral phase usually doesn't require any switch.

Static Transfer Switches by Transfer Time

The transfer time of a static transfer switch refers to how long it takes for the switch to transfer the load from one input source to another. It is an important factor influencing power quality and system performance. As mentioned above, static transfer switches employ solid-state devices such as thyristors to achieve fast transfer times. This makes them suitable for applications that require immediate action. Static transfer switches with different designs can have varying transfer times. Surprisingly, some of them can achieve almost instantaneous transfers on the order of milliseconds or less, while others may have transfer times in the range of 10 milliseconds to 100 milliseconds.

Static Transfer Switches by Configuration

The configuration of a static transfer switch usually refers to the way it is structured and connected in power systems to achieve load sharing or power supply switching.

Two sources of power supplies are provided in parallel in the redundant configuration, and a static transfer switch is used to connect the load to the two power supplies. In addition to providing continuous supply to the load, the parallel configuration also facilitates maintenance and servicing of individual supplies without interrupting the load supply.

In the shared configuration, the STS distributes the load to multiple power supply sources via the same switch. This configuration is usually used in large systems to improve system reliability and availability.

Static Transfer Switches by Switching Capacity

Static transfer switches with low switching capacities are designed to handle small to moderate loads. They are usually used in commercial establishments, offices, and data centers. On the contrary, high-capacity static transfer switches are built to manage large power loads. They are typically employed in large-scale industrial facilities, critical infrastructure, and data center environments. High-capacity STS units can handle significant levels of power and ensure the reliability of power supply for essential systems.

Specification and Maintenance of Static Transfer Switch

Some key specifications need attention when looking for a 3-phase static transfer switch. They directly influence performance, capacity, and compatibility.

• Capacity (kVA): The capacity is the maximum power the static transfer switch can handle, measured in kilovolt-amperes (kVA). Business buyers must choose a switch with a capacity rating that fits their electrical load requirements to avoid overloading.
• Input/Output Voltage: The input and output voltage ratings determine the switch's operating voltage range. It ensures that the switch can handle the voltage levels of the incoming AC power sources and the load devices.
• Frequency: The static transfer switch's operating frequency, typically 50/60 Hz, must match the frequency of the AC power sources in use. A proper frequency match ensures smooth energy source transitions and control.
• Control System: Understand the control systems used in static transfer switches. Some may include manual controls (e.g., push buttons, switches) for user intervention. In contrast, others incorporate automated features like digital controllers with display screens, remote monitoring, and alarming capabilities for unattended settings.
• Protections: Selective overcurrent protection, surge protection, and fault protection are critical to static transfer switches. Overcurrent protection ensures devices are safeguarded against excessive currents. Surge protection shields them from transient voltage spikes caused by events like lightning strikes. Fault protection mechanisms detect and respond to electrical faults, such as short circuits, preventing equipment damage and ensuring safe operation.
• Physical Size and Weight: The physical dimensions and weight of the static transfer switch affect installation requirements, space constraints, and handling considerations. Business buyers must assess how the size and weight of the switch will impact its integration into existing electrical systems.

Maintaining a static transfer switch is crucial to ensuring it works well. Regular maintenance helps find and fix any problems before they become serious. A scheduled maintenance program should include routine checks and inspections, along with any repairs or part replacements needed, to provide an extended life for the switch. It's essential always to follow the maintenance guidelines provided by the manufacturer to keep the device operational and safe.

Scenarios of Static Transfer Switches

The main purpose of a static transfer switch is to maintain an electrical load by offering redundancy, ensuring that power does not go off. However, while this remains the main scenario for static transfer switches across numerous industries, many other usage scenarios exist.

• Data centers and IT infrastructure

  Static transfer switches are widely used in the power distribution systems of data centers to ensure the continuous operation of IT equipment. They enable IT equipment to smoothly transfer its power supply from one source to another with no power interruption. Usually, a static transfer switch connects two UPS systems or two utility grids that serve as power supplies to computing facilities in data centers. Whenever there are incidents within a power source, the static transfer switch will transfer power to another unaffected power source within a given time, ensuring that computing facilities, critical servers, and other IT infrastructure within the data center do not experience system downtimes.

• Industrial control systems

  Many industrial systems are heavily dependent on automatic control systems to run and operate smoothly. Such industrial systems include power generation factories, petrochemical factories, public transportation systems, manufacturing setups, etc. Any interruption in power supply can lead to unfortunate situations like system malfunctions, production stoppages, or even catastrophic accidents. Often, industrial control systems need stable and continuous functioning of power supply so that they can support independent automatic control, monitor, and regulate processes within factories, and intersection, and ensure smooth operating activities. Systems like these would always use a static transfer switch to ensure that critical loads or automatic control systems remained powered on no matter the circumstances going on within a power source.

• Healthcare medical facilities

  Modern healthcare facilities like hospitals and laboratories require a steady and reliable power supply for their medical equipment, diagnostic instruments, and monitoring systems. A static transfer switch ensures that medical devices in critical care units like intensive care, operating theaters, and emergency rooms have continuous power. Also, with static transfer switches, healthcare facilities can provide uninterrupted power to their medical equipment, even in cases where there are faults, malfunctions, or maintenance going on in a power source system, thereby ensuring patient safety and optimal functionality of medical devices.

How to choose static transfer switches

When planning to buy static transfer switches for resale, buyers will need to consider factors like quality, benefits for customers, price, and how successful the marketing strategy will be.

• Quality: The buyer will have to spend time looking for manufacturers or suppliers with quality static transfer switches. They can ask for certifications and assurance that the switches will last long and perform well. A good quality switch is made of durable materials and has strong construction.
• Benefits for customers: The buyer will have to examine how the static transfer switch will benefit potential customers. Some benefits include seamless, fast switching between power sources and the provision of reliable power. Extra features like surge protection, overload protection, and indicator lights can also give it more value. Customers would want transfer switches that are safe, easy to use, and understand, with a clear manual. If some switches require extra maintenance or, in some cases, installation, customers will want to know this.
• Markup and pricing: The price at which end users will sell the product will depend on the markup or margin needed to make a profit. Static transfer switch prices can vary depending on the supplier and offer needed for the switches. Generally, the price is model-specific and amounts range are stator based.
• Marketing: Retail buyers will need to see how they can market the products. They can talk to commercial end users like hospitals, manufacturing plants, and data centers, and find out what type of transfer switches they need. They can also find out about quantities and specific requirements for these commercial end users. This information can guide the buyer about what types of static transfer switches they need to buy.

Static transfer switch prices FAQ

Q1: What is the cost difference between 2pole and 3pole static transfer switches?

A1: Generally, 3pole static transfer switches are higher than 2pole ones. The price difference is mainly due to the additional components and complexity associated with 3pole static transfer switches. While exact prices can't be given, the cost difference between 2pole and 3pole static transfer switches is likely to be a few static transfer switch prices.

Q2: Why do those with larger capacities, such as >500A, tend to have higher prices?

A2: The price of a static transfer switch tends to increase with capacity. This is because they need larger and more durable components to handle the higher power levels and ensure reliable operation. Additionally, the design and manufacturing processes need to ensure the switch can handle the higher currents contribute to the higher cost.

Q3: What are the main factors Static transfer switch price differences between brands?

A3: The quality and reliability are crucial in determining the performance of critical systems. The level of technology used in the switches, such as the speed of the circuitry and the sophistication of the control systems. The range of products offered by a brand, from entry-level to industrial-grade switches, Static transfer switch prices also differ. Q4: Why are some static transfer switch prices higher but not higher?

A4: Different manufacturers may use other sourcing strategies, such as securing long-term contracts with suppliers to stabilize costs, or focusing on just-in-time manufacturing that may require higher inventory levels.