3. Installation
3.1 Notice for selection
For selection, refer to the catalog, technical data, specifications and other technical materials.
For any question concerning the selection method, please enquire us.
We are not responsible for any failure and damage caused by wrong selection.
3.2 Normal service conditions
Our circuit breakers of the standard specifications are to be used in the following standard conditions.
• Operating ambient temperature: –10 to 40°C (Average temperature for 24 hours, however, shall
not be higher than 35°C.)
• Relative humidity: 85% max. with no dewing
• Altitude: 2,000 m maximum
• Ambient of no excessive water or oil vapour, smoke, dust, salt content, corrosive substance, vibra-
tion, and impact
Expected service life (MTTF) under the above conditions is 15 years.
• Lowering ratio of operational current in special ambient temperature over 40°C.
50°C.........0.9 times
60°C.........0.7 times
Expected service life (MTTF) will be reduced compare with normal service conditions.
• Refrain from installing in any unusual environment of high temperature, high humidity, dust,
corrosive gas, vibration and impact. Electrification, fire, and malfunction can result.
Note. The environment shall be free from any dewing or freezing.
17
CAUTION