BS EN 60034-5:2001 – Rotating electrical machines — Part 5: Degrees of protection provided by the integral design of rotating electrical machines (IP code) — Classification

4 Degrees of protection – First characteristic numeral
4.1 Indication of degree of protection The first characteristic numeral indicates the degree of protection provided by the enclosure to persons and to the parts of the machine inside the enclosure. Table 2 gives, in the third column, brief details of objects which will be ‘excluded’ from the enclosure for each of the degrees of protection represented by the first characteristic numeral. The term ‘excluded’ implies that a part of the body, a tool or a wire held by a person, either will not enter the machine or, if it enters, that adequate clearance will be maintained between it and the live parts or dangerous moving parts (smooth rotating shafts and the like are not considered dangerous). The third column of table 2 also indicates the minimum size of solid foreign objects which will be excluded.
4.2 Compliance to indicated degree of protection Compliance of an enclosure with an indicated degree of protection implies that the enclosure will also comply with all lower degrees of protection in table 2. In consequence, the tests establishing these lower degrees of protection are not required, except in case of doubt.
4.3 External fans The blades and spokes of fans external to the enclosure shall be protected against contact by means of guards complying with table 1 .
For the test, the rotor shall be slowly rotated, for example by hand when possible.
Smooth rotating shafts and similar parts are not considered dangerous.
4.4 Drain holes
If the machine is provided with drain holes, the following shall apply:
– drain holes intended normally to be open on site shall be kept open during testing;
– drain holes intended normally to be closed on site shall be kept closed during testing;
– if machines with protection IP3X or IP4X are intended to be run with open drain holes, the drain holes may comply with protection IP2X;
– if machines with protection IP5X are intended to be run with open drain holes, the drain holes shall comply with protection IP4X.
BS EN 60034-5:2001 – Rotating electrical machines — Part 5: Degrees of protection provided by the integral design of rotating electrical machines (IP code) — Classification