What do the Standards Say?

 

The standards do not specify an actual IP rating however they actually determine the protection within two areas,

 

8.4.2.2 – Basic Insulation Provided by Insulating Material

Summarising that “Hazardous Live parts shall be completely covered with insulation that can only be removed by destruction or by use of a tool”. This further goes on to say that “The insulation shall be made of suitable materials capable of withstanding the mechanical, electrical and thermal stresses… subject to service”

 

8.4.2.3 – Barriers or Enclosures

Summarising that “Air insulated live parts shall provide at least IP XXB” & “Top surfaces of enclosures <=1.6 Meters above the standing area shall provide a degree of protection of at least IP XXD”

 

What are IP XXB & IP XXD

 

What is IP XXB - This means protection against ingress of solid foreign objects and water is not required. The access to hazardous parts is protected for incidental contact with fingers, meaning you should not be able to insert a standard sized finger into the equipment and touch live parts

 

What is IP XXD - This means protection against ingress of solid foreign objects and water is not required. The access to hazardous parts is protected for incidental contact with wire, meaning you should not be able to insert a piece of wire of 2.5mm diameter and 100mm length into the equipment and touch live parts.

 

 

 

 

 

 

 

 

 

 

 

What do I Specify?

 

Commonly most manufacturers will use IP 31 as external protection as a standard throughout, suiting the IPXXD, with a common application of IP 2X internal protection throughout suiting IPXXB, meaning within the compartment doors, excluding direct door/cover access to busbar chambers. This covers the standard application, including that extra protection of vertical water from above. 

 

In a typical application to comply with the standards and the inclusion of typical manufacturing standards (this being above and beyond) including the additional water ingress protection the following, or similar must be stated:

 

All Low Voltage Switchgear must comply with IP 3XD, this ensuring particular mechanical protection to suit the particular application. This covering both aspects as found in BS 61439-1:2011 - 8.4.2.2 & 8.4.2.3.

 

However it is advised to go one step further and specify as below, as this is a typical application of most UK manufacturer's,

 

All Low Voltage Switchgear must comply with IP 31D, this ensuring particular mechanical and water ingress protection to suit the particular application. This covering both aspects as found in BS 61439-1:2011 - 8.4.2.2 & 8.4.2.3.

 

IP Ratings & Practical Applications

 

However different applications require different elements of protection, this being project-specific, such solutions to suit requirement are available and can be devised around site specifics, such popular solutions are GRP's or allocated surrounding enclosures which can be developed to suit various applications.

What is important here is a practical application, there is no point specifying, and more importantly paying for an IP66 application if it is not required. All IP ratings mentioned above are possible to implement and different manufacturers vary upon what they can and do offer, this is generally due to materials used in construction of the equipment and the overall temperature rise., This being a vital consideration when specifying the IP rating, due to the  I²R Losses (Watt Losses/Heat dissipation) which generally increases with any switchgear's current rating, understandably greater IP ratings cause a reduction in natural air flow, therefore reducing the removal of heat drawn out of the Switchgear.