IEC 62271-1 sets minimum enclosure protection: IP1XB against access to hazardous parts and solid objects, IPX3 against water for outdoor equipment, IK07 preferred indoors and IK10 as a minimum outdoors without additional mechanical protection. Tests are made on the complete enclosure and only when there is doubt about compliance.
Short answer
The enclosure of a switchgear assembly, a circuit breaker or a control cabinet must protect people from contact with hazardous parts and protect the equipment from the ingress of objects, water and impacts. IEC 62271-1 (2017 edition, clause 6.14) sets minimums using the IP code of IEC 60529 and the IK code of IEC 62262. The product standard may require more.
IP code: contact and foreign objects
The IP code has two digits and optional letters. The first digit indicates protection against the ingress of solid objects and access to hazardous parts. The second, protection against water. An X indicates that characteristic is not specified.
Clause 6.14.2 requires the enclosure to give at least IP1XB against access to hazardous parts of the main circuit, the control and auxiliary circuits and hazardous moving parts, and against the ingress of solid foreign objects.
IP code: water
Clause 6.14.3 distinguishes two cases:
- Indoor equipment: there is no minimum protection against water. The second digit is X.
- Outdoor equipment: at least IPX3. If it has additional protection against rain and other weather conditions, marked with the supplementary letter W, performance refers to the situation with those elements in place and must be demonstrated using Annex C of the standard.
IK code: mechanical impact
Clause 6.14.4 deals with impacts in normal service, using the scale of IEC 62262:
| Installation | Impact level |
|---|---|
| Indoor | IK07 preferred (2 J) |
| Outdoor without additional mechanical protection | IK10 as a minimum (20 J) |
Insulators and bushings of high-voltage switchgear are not subject to this requirement.
How to read each code
| Code | What the standard sets | Where |
|---|---|---|
| IP1XB | Minimum for every enclosure: access to hazardous parts and solid objects | IEC 62271-1, 6.14.2 |
| IPX3 | Minimum against water for outdoor equipment | IEC 62271-1, 6.14.3 |
| IPXXW | Alternative for outdoor metal-enclosed switchgear, with additional weather protection | IEC 62271-200, 5.13.2 |
| IP2X | Minimum for the enclosure of installed metal-enclosed switchgear | IEC 62271-200, 5.102.1 |
| IK07 | Preferred impact indoors (2 J) | IEC 62271-1, 6.14.4 |
| IK10 | Minimum impact outdoors without additional mechanical protection (20 J) | IEC 62271-1, 6.14.4 |
Clause 6.14.1 requires enclosures to meet these degrees, including those of the control and of the auxiliary equipment that forms part of the equipment. When the code carries an X in a position, the standard sets no minimum for that characteristic.
Since the type test does not install the real cables, the demonstrated degree corresponds to the enclosure with dummy pieces at the entries. When cables are installed, the entries must be closed with the elements the manufacturer specifies to keep that degree.
The switchgear assembly as a particular case
Product parts add requirements on top of the general one. For metal-enclosed switchgear from 1 kV to 52 kV, IEC 62271-200 (2011 edition, clause 5.102.1) requires the installed enclosure to give at least IP2X with all doors and covers closed, regardless of how they are held in position. It allows a higher degree to be specified per IEC 60529. Outdoors it requires IPX3 or IPXXW, and indoors a minimum impact of IK07 (clauses 5.13.2 and 5.13.3 of that standard).
That is why the IP degree of a switchgear assembly is read from the standard for its type and from the manufacturer’s nameplate, and not only from IEC 62271-1.
Internal arc is a requirement distinct from the IP and IK codes: the internal arc classification (IAC) and the accessibility types A and B for internal arc deal with it. The condensation and pollution classes in switchgear cover condensation and pollution of indoor switchgear.
The other parts of IEC 62271 are organized in the standards for primary equipment testing.
How it is verified
IP (clause 7.7.1). The tests follow clauses 11, 12, 13 and 15 of IEC 60529. They are made on the complete enclosure, mounted as in service. Since the real cables are not installed in a type test, dummy pieces are used where they enter. Shipping units are closed with covers that give the same protection as the joints.
IK (clause 7.7.2). It is demonstrated per IEC 62262, also on the complete enclosure. After the test, the enclosure must have no breaks, and the deformation must not affect the normal function of the equipment, reduce the insulation or creepage distances, or lower the degree of protection against access to hazardous parts below what is allowed. Surface damage, such as removed paint, broken cooling fins or small dents, can be ignored. Auxiliary equipment that forms part of the enclosure, such as meters and relays, receives no impacts in this test.
When they are done. Both verifications are made only if there is doubt about compliance with the requirement, and in each position of the relevant parts that is considered necessary.
- Is the equipment installed indoors or outdoors?
- Indoor: IP1XB as a minimum; no minimum against water; IK07 preferred
- Outdoor: Does it have additional mechanical protection?
- Yes: IP1XB and IPX3 as a minimum; the impact is defined by the additional protection
- No: IP1XB, IPX3 and IK10 as a minimum
What not to do
- Do not treat IP1XB and IP2X as equivalent: the metal-enclosed switchgear of IEC 62271-200 requires at least IP2X.
- Do not require IK10 for bushings or insulators: the standard exempts them.
- Do not assume outdoor equipment with the letter W complies merely by carrying it: it must be demonstrated with Annex C.
- Do not take impact as demonstrated for meters and relays mounted in the enclosure: the standard exempts them from the IK test.
When to call us
At Tiza Group we inspect the switchgear assemblies and cabinets of your substation at receiving and commissioning, and check that what was delivered matches what was specified. See our testing and commissioning service, in Colombia or elsewhere on request. Write to us and we will quote it.
Related guides
- Condensation and pollution classes in indoor switchgear
- Internal arc classification IAC of a switchgear assembly
- Accessibility types A and B in switchgear with internal arc
- Medium-voltage switchgear: parts, functions and tests
- Circuit breaker control cabinet: parts and functions
References
- IEC 62271-1, High-voltage switchgear and controlgear - Part 1: Common specifications for alternating current switchgear and controlgear, 2017 edition: clauses 6.14.1 to 6.14.4, 7.7.1, 7.7.2 and Annex C.
- IEC 62271-200, 2011 edition: clauses 5.13.2, 5.13.3 and 5.102.1.
- IEC 60529 (IP codes) and IEC 62262 (IK codes), cited by the standard.
Frequently asked questions
What minimum IP degree does IEC 62271-1 require for a switchgear enclosure?
At least IP1XB against access to hazardous parts of the main, control and auxiliary circuits, and against the ingress of solid foreign objects (clause 6.14.2). For outdoor equipment, at least IPX3 against water is also required (clause 6.14.3).
Which IK impact level applies to indoor switchgear and to outdoor equipment?
For indoor installation, the preferred level is IK07 (2 J). For outdoor without additional mechanical protection, the minimum is IK10 (20 J). Insulators and bushings are not subject to this requirement (clause 6.14.4).
Is every switchgear assembly tested for IP and IK at the factory?
Not systematically. Clauses 7.7.1 and 7.7.2 state that IP and IK tests are made only if there is doubt about compliance, on the complete enclosure mounted as in service.