How do we assemble a switchboard once it is delivered to our warehouse? There are four things we need to consider. First, the IP and IK degrees, second, the mechanical assembly, third, earthing continuity, and lastly, the quality control checklist.

Let’s start by talking about the IK and IP degrees of protection. According to IEC 60529, “Enclosures must protect equipment against environmental risks and persons against accidental contact with a powered equipment part.”

Meanwhile, IEC 62262 states, “The characteristics of the room in which the switchboard will be installed make it possible to: – define an IK degree of protection, – define an IP degree of protection, – choose an appropriate switchboard type (kit, switchboard for critical applications, universal enclosure, etc.).”

For example, the minimum IK degree of protection for Schneider Electric universal enclosures is IK10.

IK Degree of Protection

Now that we’ve mentioned IK10, what exactly does the IK degree of protection mean? Based on IEC 62262, “an IK protection code defines the ability of enclosures to resist external mechanical impacts on their entire surface. Each code represents a value of the impact energy for a weight dropped from a height h.”

We can better understand this if we look at the figure below.

Along with that figure, let’s also look at the table.

That is why every time we perform the tests, we make sure that the mechanical resistance of the enclosure undergoes a standard mechanical resistance performance test carried out in compliance with the guidelines of the standard. This process verifies and validates the IK performance specified by the manufacturer. Any deformations resulting from an IK test must in no way compromise the safety of the switchboard. The IP protection index of the enclosure must remain intact, and the clearances between any live bare parts and the enclosure components must be preserved.

In the picture, a certain clearance is chosen for the IK type tests during the study of the types of switchboards. If maintaining that distance is not possible, we place an insulating barrier between the live parts and the enclosure walls.

IP Degree of Protection

Now, what about the IP degree of protection? According to the IEC 60529 standard, the IP code is made up of two characteristic digits. The first digit defines the protection of persons and equipment against the ingress of foreign solid bodies, while the second digit defines the protection against the ingress of water with harmful effects. For example—

Also, IEC 60529 standard defines a code that characterizes the IP degree of protection provided by an enclosure of electrical equipment against: – access to hazardous parts, – the penetration of solid foreign bodies, – the penetration of water.

It is important to remember that the IP code must always be read and understood digit by digit, and not as a whole. There are instances that illustrate this. For example, an IP31-rated enclosure can be used in an environment that requires a minimum protection rating of IP21. However, an IP30 enclosure would not be suitable. To further improve the effective protection of persons against access to hazardous parts, the IP code may also be completed with an additional letter.

This letter defines a higher protection than the one specified by the first digit of the IP code:

When only personnel protection is worth mentioning, the two characteristic digits of the IP code are replaced by the letter X (example, IPXXB).

Assignment of an IP degree of protection

The IP degree of protection of a switchboard accessible to unqualified persons must always be at least IP2X. Example: For enclosures in kit form, the IP degree of protection is at least IP30: control handles of devices may be operated in all safety.

The IP degree of protection assigned to a switchboard is subject to an agreement between the manufacturer and the end user: – the end user must determine the desired degree of protection depending on the environment in which the switchboard will be installed, – the manufacturer must install appropriate components (enclosures, switchgear and controlgear, accessories) and mount them in accordance with the supplier’s instructions to reach the required degree of protection.