The Requirements and Responsibilities of Smart Appliances
Learn more about some of the regulatory EMC requirements and associated responsibilities of placing IoT appliances and transceivers on the market.
The Internet of Things (IoT) is a vast network of goods that connect to the internet for the exchange of data. One consumer product that looks to take advantage of this technology is home appliances. The availability of IoT connected appliances to the consumer has been ramping up significantly in recent months. These “smart” appliances could include wearable devices, alarm systems, garage door openers, HVAC systems, kitchen appliances, washers/dryers and other white goods. It is the goal of IoT to enable all appliances to connect and interact with each other regardless of the manufacturer. The user will be able to interact with these connected appliances through their wearable device, smart phone, tablet, computer or digital assistant (i.e. Amazon’s Alexa) to control or get information from the appliance. Certain appliances might be controllable by the utility companies, for instance, turning off the AC system during peak demand hours, with the homeowner’s authority of course.
Most of this connectivity will be done wirelessly using wireless technologies like Wi-Fi, Bluetooth, Z-Wave, WeMo, Thread, and Zigbee. These wireless technologies will have to work together seamlessly and safely while also not causing interference to other wireless technologies or other digital technologies. The manufacturer of these IoT appliances must comply with a number of compulsory electro-magnetic compatibility (EMC) regulations which provide a level of confidence in meeting that goal. These EMC regulations generally state that the device must work in the environment in which it is intended without causing radio frequency interference, and must accept interference without causing unsafe operation.
Wireless testing at D.L.S. Electronic Systems.
The objective of this article is to help the reader recognize some of the regulatory EMC requirements and associated responsibilities of the manufacturer or the company placing IoT appliances and transceivers on the market.
Domestically, the FCC (United States) and ISED (Canada) are the regulatory authorities who set EMC regulations on appliances and wireless products. Appliances that use radio frequency (RF) energy to perform a task, such as microwave ovens and induction cooking appliances, are subject to FCC Part 18 and ISED ICES-001. These regulations set limits on radio frequency radiation from these appliances. Other appliances may be exempt from FCC and ISED authorization procedures providing that the digital electronics in the appliance is used solely for the function of the appliance. It should be noted that ISED Canada has announced their intent to publish an EMC standard (ICES-007 - Household appliances, electric tools, toys and similar apparatus), which is expected to be based on CISPR 14-1 Edition 6. When a communication technology is added to an appliance, then these digital electronics are subject to meeting FCC Part 15 and ISED ICES-003 requirements. In the cases where wireless communication technology is added to an appliance, then the appliance must be tested to the appropriate FCC and ISED regulations. This is usually FCC Part 15 Subpart C, and one of ISED Canada’s Radio Standard Specifications (RSS). Essentially, the radio and digital electronics are tested for compliance when installed in the appliance. The appliance manufacturer may elect to purchase from another company and install a radio module that has been pre-certified for sale in the United States and Canada (called a modular approval). In these cases, the appliance manufacturer may use the radio module in their appliance per the radio module manufacturer’s instructions without the need for any further certification of the radio device. However, the appliance manufacturer has the responsibility to perform radiated emissions testing to ensure that the radio is still in compliance with radiated emissions requirements applicable to the radio when installed in the appliance. Appliances with radio products installed are also subject to FCC and ISED requirements for labeling and user information.
The European Union does not have any exemption for appliances. Most appliances containing digital electronics must meet the requirements of the EMC Directive, which specifies compliance for both RF emissions (EN 55014-1) and immunity to RF interference (EN 55014-2). Adding an IoT transceiver into an appliance entails additional compliance considerations. While the European Union has no similar modular approvals like the FCC and ISED, an appliance manufacturer can purchase a CE marked radio module for integration into their product. It must be pointed out that when an appliance has a wireless radio permanently installed in it, the appliance becomes a radio product and is therefore subject to meeting the requirements of the Radio Equipment Directive (RED). In other words, if the radio equipment (CE Marked or otherwise) has been incorporated in a permanent way in the appliance at the time the appliance is placed on the market, the appliance is deemed to be a single product.
Radio products are subject to the Radio Equipment Directive which specifies meeting test standards for spectrum use and radio performance, EMC requirements, and product safety. The conformity assessment procedure for the combined radio/electrical product shall include a risk assessment which shall consider the combination and interaction of the different radio/electrical products to ensure that the radio in combination with the appliance does not cause any undesired or unsafe operation.
The combination of these products shall be considered during the risk assessment as one single functional unit. Much of the CE marked radio conformance test data can be used in this assessment, but if the radio was not tested in a similar application to their appliance, then testing must be performed on the combined product (appliance with radio). Almost all cases will require some ETSI/EN standards radiated emissions testing as well as some immunity testing. The manufacturer, importer or other responsible party making the product available on the market shall be identified and shall undertake sole responsibility of the compliance of these finished radio/electrical products.
In the case of both domestic (FCC & ISED Canada) and European Union regulations, the exposure of the user to radio frequencies must be assessed for compliance with the respective regulatory requirements as pertains to the radio’s use in the appliance. Often, when pre-approved or CE marked radio modules are used, if the radio is used as intended by the radio module manufacturer, including the antennas used and the distance of the antenna to the user, then the radio compliance RF exposure compliance documents can be referenced for compliance in the appliance. For example, if a purchased and pre-certified radio module provides in its user guide evidence of compliance with RF exposure regulations with the antenna spaced at a distance greater than or equal to 40cm from the user, the use of the radio in the appliance must maintain that specified distance. Installation into the appliance of the radio’s antenna at a distance less than 40cm will require re-assessment of the RF exposure compliance. When the appliance manufacturer integrates more than one radio product into the appliance, then the combined RF from both radios must be used to determine compliance with RF exposure regulations. The user’s manual or guide that is provided to the end user must include a description of how this RF exposure compliance is met.
In summary, the IoT appliance manufacturer must consider the EMC compliance of the appliance and IoT device combined. The use of a pre-approved or CE marked radio product may effectively reduce the EMC regulatory compliance burden of the manufacturer, but the EMC compliance of the whole product must be assessed and usually includes some testing, as well as product marking/labeling and user information requirements. The route to compliance may not always be easily followed or understood. I’ve provided below a list of links which should help the reader find much of the guidance necessary for EMC compliance. If one cannot find enough clarity through their own investigations, then do not hesitate to work with any of the reputable and highly educated test labs and EMC compliance consultants who work hard to understand and keep current with current regulatory requirements.