Some types of Ex Equipment, such as large electric motors, are provided with additional Equipment or Components which carry out a function that is not integral with the main function of the Ex Equipment. In the case of a large motor this might include, for example, bearing temperature detectors, bearing vibration detectors and a water level detector in the drip tray of a water cooled motor.
The terms “Ex auxiliary equipment” (which may include Ex associated equipment, as defined in IEC 60079-0) and “Ex component” will be used in this Decision Sheet, to differentiate it from the Ex Equipment.
For the purposes of this Decision Sheet, it is assumed that the Ex auxiliary equipment and Ex components already have separate IECEx certifications.
The purpose of this Decision Sheet is to provide guidance on how to deal with such Ex auxiliary equipment and Ex components in the Ex Equipment Certificate and in the marking of the Ex Equipment.
This decision sheet is not intended to address Ex auxiliary equipment or Ex components, unless itis used in conjunction with the Ex Equipment and mounted in or on it.
This decision sheet is not intended to address assemblies of equipment which are within the scope of IEC TS 60079-46.
Basic principle: The IECEx certificate is intended to provide a clear understanding for purchasers and users of the Ex Equipment of what parts of the Ex Equipment are covered by the certificate itself and what part(s) of the Ex Equipment are covered by separate Ex Component or Ex Equipment certificates.
An example of such Ex Equipment would be an “eb” motor that includes Ex auxiliary equipmentand Ex components like an Ex Component “eb” terminal box, an Ex Equipment “ib” bearing temperature monitor, and an Ex Equipment “ib” vibration monitor.
Question 1, identification:
How should the Ex auxiliary equipment and Ex components be referenced in the Ex Equipment Certificate?
All Ex auxiliary equipment that, at the time of the Ex Equipment certification, is intended to be installed on/in/with the Ex Equipment, shall be listed in the Ex Equipment Certificate. Where convenient, this might be in the form of a table with columns headed: Ex auxiliary equipment, Manufacturer, Certificate Number, Marking Code.
The technical evaluation of Ex auxiliary equipment by the ExCB should be limited to confirming that the Specific Conditions of Use are adhered to, and that the method of mounting and connecting the Ex auxiliary equipment does not negate the value of its certificate. Because the Ex auxiliary equipment certificates do stand on their own, the relevant marking codes from the Equipment do not become part of the marking code of the Ex Equipment.
The technical evaluation of Ex Component(s) extend(s) to a full review of the Schedule of Limitations and, if any, to the assessment of technical differences (see ExTAG DS 2014/001). Because the Ex Component Certificate is incomplete, the relevant marking codes from the Ex Component become part of the marking code of the Ex Equipment.
The certificate shall list all relevant protection method marking codes based on the Ex components that can be used in the Ex equipment.
The standards listed shall only be those related to the Ex equipment and Ex components, not the Ex auxiliary equipment.
Question 2, marking:
What are appropriate ways for dealing with Ex Equipment marking when Ex auxiliary equipment and/or Ex component(s) may, or may not, be present?
The purpose of the marking on an Ex Equipment marking plate is to provide immediate guidance to those that may be inspecting the equipment but do not have immediate access to the certificate.
Where the Ex equipment contains Ex components, the relevant marking of the Ex components has to be incorporated in the marking of the Ex Equipment.
Where the Ex equipment may be used with Ex auxiliary equipment, it is not required that the relevant marking of the Ex auxiliary equipment be included in the marking of the Ex equipment.
So again basic understanding of marking and all behind is a minimum input of Ex compliance.
Source: iecex.com (ExTag)