Which IEC power standards should you be familiar with when designing smart appliances?
Without a doubt, the market for smart devices, as well as the smart appliance industry, is quickly expanding.
According to Statista, the revenue in the smart appliances market segment is expected to reach $38.4 billion this year, with 262 million households predicted to be using smart appliances by 2025.
And the types of smart appliances available have expanded to include microwaves, refrigerators, thermostats, ovens, air fryers, ice makers, and pressure cookers.
Smart devices and the Internet of Things (IoT) are becoming more common in the home, ranging from front-door smart doorbells to more complex smart thermostats that can optimize energy consumption and smart refrigerators that can warn you when particular goods are running short.
Smart household appliances must adhere to a distinct set of regulations than other smart devices, and compliance must begin with the design process. Compliance with the appropriate power-related requirements, in particular, is important for success in the burgeoning smart home appliance industry.
Identifying and following the appropriate standard as early as possible in the design phase can simplify decision-making and shorten time-to-market.
Smart Household Appliances
Household appliances are not as simple as they were in the past, and they are rapidly taking advantage of IoT (Internet of Things) capabilities and intelligent systems. Appliances can have graphical displays and wireless connectivity that makes them very similar to ITE (Information Technology Equipment) applications, but they do differ from smart devices classified as ITE, ICT (Information and Communications Technology), and AV (Audio Video).
The main distinctions are in how they’re used, who uses them, where they’re utilized, and how people engage with them. Smart televisions, which are categorized as smart appliances and can be found in people’s living rooms and bedrooms all over the world, have made it much simpler to enjoy life and streaming entertainment.
Smart refrigerators, on the other hand, are located in the kitchen and may make choices based on artificial intelligence as well as interact with other devices and applications to do activities such as giving users warnings when specific goods are running short or placing orders on their behalf.
Smart household appliances can be programmed by the user and provide automation at some level (e.g., turn the coffee maker on at 6 a.m. or set the thermostat to a higher temperature when everyone is gone from the house), but also make decisions on their own via artificial intelligence (e.g., adjust the thermostat settings to minimize energy consumption).
Household The Smart Appliance Safety Standards
IEC 60335-1, which is related to IEC 60950 and IEC 62368-1 in certain aspects, is the safety standard for home appliances (including smart home equipment). The IEC 60335-1 standard, on the other hand, recognizes that modern household appliances may be internet-connected and are more likely to have electronic controls than manual controls, in order to accommodate smart household equipment.
Newer standards, including IEC 62368-1, focus on Hazard-Based Safety Engineering (HBSE). This means that potentially hazardous energy sources and the mechanisms that could allow energy transfers from occurring are identified, and measures are taken to prevent them. And not only are safeguards put into place but their effectiveness must be evaluated.
Harmonization of Standards
It is difficult to harmonize standards for household appliances, especially smart models. In North America, Mexico (NMX-J-531/1-ANCE), the United States (UL 60335-1), and Canada (CAN/CSA-C22.2 No. 60335-1) have utilized IEC 60335-1 as the foundation for a tri-national standard.
However, not all of UL 60335’s 100+ part 2 requirements pertaining to particular goods are recognized in the United States. Unlike the US, the European standard EN 60335-1 recognizes the majority of part 2 standards.
IEC Power Standards Comparison: IEC 60950, IEC 62368, and IEC 60335
In the area of power supply, there are some variations between IEC 60950, IEC 60335, and IEC 62368, and it is frequently true that the easiest approach to learn about a new standard is to compare it to an existing standard.
IEC 60335 is often more rigorous than IEC 63268 and its widely used predecessor, IEC 60950. In the context of power supply and external adapters, the following table compares IEC 60335 to the well-known benchmark 60950 standards for information technology equipment.
Current Leakage Requirements
Consider current leakage: The IEC 60335 standard limits leakage current to 0.75 mA for portable appliances and 3.5 mA for stationary appliances.
IEC 60950, however, has three different categories (hand-held, movable, and stationary), and the leakage current for all three of these (including portable) is the same as what IEC 60335 requires for stationary appliances: 3.5 mA.
Creepage requirements for working voltages between 250 VAC and 300 VAC with reinforced insulation are as follows: IEC 60950 requires 6.4 mm while IEC 60335 requires 8.0 mm. Keeping in mind that creepage, as shown in Figure 2, refers to the shortest path along the insulation surface between two conductive parts, IEC 60335 is more stringent.
However, for clearance (which is the distance between two conductive parts through the air) under the same working conditions, IEC 60950 requires 4.0 mm, and IEC 60335 requires only 3.5 mm.
Isolation Voltage Requirements
Another example of differences lies in the isolation voltage, which refers to the maximum voltage applied for a short period between a power supply’s input and output or chassis.
The IEC 60950 standard specifies a fixed value of 3 kV for input-to-output isolation and a maximum output-to-ground working voltage of 500 V for output-to-ground working voltage. IEC 60335, on the other hand, simply specifies a 2.4 kV + (Working Voltage x 2.4) input-to-output isolation voltage requirement, with no maximum output-to-ground working voltage.
Meeting IEC 60335-1 Standards with CUI Power Supplies
In the expanding (and fiercely competitive) smart appliance industry, finding the proper power supply that satisfies the right set of requirements is critical. Navigating the IEC 60335-1 standard to ensure that the power supply or adapter is completely compatible, on the other hand, might be difficult.
CUI’s power supplies are designed to meet the stringent standards of IEC 60335-1. The first is the PBO-3C/5C/10C Series (3-10W), shown in Figure 3, which are open frame board mount AC-DC power supplies in an ultra-compact SIP package. Not only are they suitable for applications with limited space, but they are also economical solutions for applications with low power demands.
The next product line is the PSK-3D/5D/10D/15D/20D/25D Series (3-25W) of encapsulated board mount AC-DC power supplies with a compact design, an input voltage range between 85 and 305 VAC, and a wide operating temperature range.
Finally, the VOF-100C/120C/180C/200C/225C/350C Series (100-350W) of power supplies are also open mount AC-DC power supplies. They are designed to reduce the standby power consumption and overall power consumption and are certified to IEC 62368, 60335, and 61558.