IEC 60721-3-7:2002 pdf download
IEC 60721-3-7:2002 pdf download.Classification of environmental conditions -Part 3-7: Classification of groups of environmentalparameters and their severities –
Portable and non-stationary use.
The environmental conditions covered by these groups include:
– the environmental conditions at locations where the product may be placed or used temporarily:
— the change of environmental parameters due to change of location;
— the environmental conditions related to transfer of the product between different locations.
The environmental conditions classified do not take into account the use profile of the product. i.e. whether the product is used only during a temporary stationary state, during the state of transfer or arbitrarily.
The conditions of portable and non-stationary use to which products may be exposed include land-based and offshore, weatherprotected and non-weatherprotected locations The conditions further include transfer which is a part of the portable and non-stationary use.
The environmental conditions specified in this standard are limited to those which may directly affect the performance of products. Only environmental conditions as such are considered. No special description of the effects of these conditions on the product is given.
Environmental conditions directly related to fire or explosion hazards and conditions related to Ionizing radiation are excluded. Any other unforeseen Incidents are also excluded. The possibility of their occurence should be taken Into account In special cases.
Microclimate within a product is not included,
Conditions of stationary use, use in vehicles, and ships, and conditions of storage and transportation are given in other sections of IEC 6072 1-3.
A limited number of classes of environmental conditions is given, covering a broad field of application. The user of this standard should select the lowest classification necessary for covering the conditions of the intended use.
4 General
For further general guidance, see IEC 60721-3-0
Products in portable and non-stationary use are sometimes transferred from one location to another without being switched on. During this transfer the environmental conditions bearing on the product may affect the product in a different way than during operation. If environmental conditions during operation are considered separately from those during transfer, another class, e.g. a lower one, may be selected for this part of the use.
The seventies specified are those which will have a low probability of being exceeded. All specified values are maximum or limit values. These values may be reached, but do not occur permanently. Depending on the local situation there may be different frequencies of occurrence related to a certain period of time. Such frequencies of occurrence should be considered for any environmental parameter, They should additionally be specified if applicable. Information on duration and frequency of occurence i5 given in IEC 60721-3-0 as clause 6.
Attention is drawn to the fact that combinations of the environmental parameters given may increase the effect on a product. This applies especially to the presence of high relative humidity in addition to biological Conditions, or to conditions of chemically or mechanically active substances.
The environmental conditions present at a location may be affected by other Influences, e.g. heat dissipation sources, special process conditions. etc.
Measurements of the environmental conditions present at a location should be made at a representative point in the vicinity of the product.
It is recognized that extreme or special environmental conditions may exist. Specifications for products to operate under such special conditions are a matter of negotiation between suppber and user,
5 Classification of groups of environmental parameters and their seventies
A number of classes for climatic conditions (K). special climatic conditions (Z). biological conditions (B), chemically active substances (C). mechanically active substances (S) and mechanical conditions (M) are specified in tables 1 to 6.
This classification allows a number of possible combinations of environmental conditions, which bear upon products wherever used. It represents the real situation in respect of worldwide conditions of use, due to local influences of open-air climate, construction of buildings, mounting, process conditions, etc. (See also clause 6.)
A class of conditions normally includes all classes with lower severity digits
For certain parameters it has not yet been possible to specify quanlitative seventies.
