Electromagnetic compatibility (EMC) is an important machinery safety issue. Electrical and electronic systems fitted to a machine can both generate and be vulnerable to interference, potentially causing a malfunction that creates a dangerous situation.
Any machine, including electrical or electronic components, must meet the Electromagnetic Compatibility Regulations 2016 to comply with the UK’s Supply of Machinery (Safety) Regulations 2008 for the Great Britain market. (Qualifying Northern Ireland goods can be placed on the GB market with the European Union’s CE and CE UKNI conformity marking.)
Machinery manufacturers are responsible for ensuring EMC compliance. Before placing equipment on the GB market, they must ensure that it has been designed and manufactured in accordance with the essential requirements in Schedule 1 of the 2016 Regulations:
a) equipment must be designed and manufactured to ensure that the electromagnetic disturbance generated does not exceed the level above which radio and telecommunications equipment or other equipment cannot operate as intended, and
b) the equipment has a level of immunity to the electromagnetic disturbance to be expected in its intended use which allows it to operate without unacceptable degradation of its intended use.
EMC testing EMC TESTING
EMC testing ensures that products meet regulatory requirements and reduces the risk of costly non-compliance. Third-party EMC tests and conformity assessments help to ensure that a product maintains its desirable features when exposed to adverse conditions (immunity test) and does not cause undue interference (emission test).
Immunity testing has three performance criteria specified in the EMC standards. Criteria A requires the product to continue operating as normal at all times and applies to tests for continuous EMC phenomena like immunity to adjacent mobile phones. Criteria B allows some degradation during the test condition, and applies to tests for transient immunity which include infrequent events, such as electrostatic discharge due to someone touching the equipment. Criteria C allows temporary loss of function and applies to severe transient immunity which is infrequent, such as a power surge or supply voltage interruptions. Permanent loss of function will be a failure.
The machinery manufacturer must also carry out a relevant conformity assessment procedure and draw up technical documentation. Once this is completed, it is also required to draw up a declaration of conformity, a document which declares that the product is in conformity with the relevant statutory requirements applicable to the specific product.
The UKCA marking, including manufacturer name, registered trade name or registered trademark, a postal address, and the type batch or serial number, must then be affixed to the machinery. Any instructions must also be supplied in English.
It is worth noting that the 2016 Regulations do not apply to new machinery displaying the CE marking that is placed on the European Economic Area or in the UK prior to 31 December 2024. This means that such machinery can continue to circulate on either market until they reach their end of use.
Over time, manufacturers must ensure they continue to conform to the 2016 regulations as adjustments are made to the manufacturing process and new or updated components are included within a machine. They must therefore take account of any changes in electrical equipment design or characteristics, and any change to a relevant harmonised standard or any technical specifications which are referred to in the declaration of conformity.
However, products that are repaired, exported for repair, refurbished or exchanged without changing their original performance, purpose or type do not need to be recertified and re-marked. Any new spare parts can comply with the same conformity assessment requirements that were in place at the time the original product was placed on the market.
FIXED INSTALLATIONS
A single item of equipment may meet these limits, but there is no guarantee that the combining items or additional components will lead to satisfactory overall emission levels. Therefore, the final integrated product must be assessed against EMC standards. Also, there are specific requirements for fixed installations. A fixed installation is defined as “a particular combination of several types of apparatus and, where applicable, other devices, which are assembled, installed and intended to be used permanently at a predefined location.”
Large installations may be regarded as fixed installations as defined by Article 3 in the Machinery Directive, and under interpretation in the regulations.
The UK regulations mean that a fixed installation must be installed applying good engineering practices and respecting the information on the intended use of its components, and meet the essential requirements set out in schedule 1 of the 2016 Regulations.
This information must be documented and held by the designated responsible person, an individual that holds a position of sufficient responsibility (see box) to control the configuration of the fixed installation.
We would therefore recommend that an EMC management or test plan is developed for any fixed installation and advise machinery owners to contractually require suppliers to submit technical documentation along with their sub systems. A management plan for larger installations should specify the intended environment and a list of appropriate standards for suppliers at the outset. All commercially available equipment, which is part of the fixed installation, must be CE or UKCA marked, and should have a declaration of conformity supported by technical documentation.
If there is no means of identifying whether the components, machines or the installation conform to the EMC requirements, machine builders must prove compatibility by EMC testing. This is reinforced by the following statement from the HSE: “If it is reasonably practicable to carry out testing for immunity to electromagnetic disturbances, the Health & Safety at Work Act requires this to be carried out”.
Section 10 of the Provision and Use of Work Equipment Regulations 1998 states that “every employer shall ensure that an item of work equipment has been designed and constructed in compliance with any essential requirements”.
While EMC may appear to be complex, it doesn’t mean that machinery manufacturers can ignore their legal obligations. Neither should machinery end-users plead ignorance, making the assumption that their supplier is doing the right thing.
BOX: RESPONSIBLE PERSON
Initially, a responsible person is the prime contractor who oversees all suppliers and the installation as well as checking and collating all EMC installation documents and approval documents. After the commissioning and handover, a responsible person will be the chief engineer, technical director or facilities manager, who will hold all EMC documentation and update this documentation as changes and upgrades occur.