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4
Environment and usage precautions
4-1 Standard conditions
4-1 Standard conditions
Because ambient conditions have a significant effect on the
short-circuit and overload characteristics, durability, and
insulating properties of circuit breakers, the conditions under
which they are used must be clarified.
For reference, Table 4-1 lists the standard operating conditions
for FUJI MCCB performance. If the ambient conditions under
which a circuit breaker is to be used differ significantly from
these standards, the circuit breaker’s characteristics may differ
considerably, and appropriate modification of usage criteria is
necessary.
Table 4-1 Standard conditions for MCCBs (IEC 60947-1)
Ambient
temperature
Operating
–5 to 40°C (the average temperature
through 24-hour does not exceed 35°C)
Storage or
transport
–25 to 55°C or the temperature under
24-hour does not exceed 70°C
Relative humidity
85% max.
Altitude
2000m max.
Pollution degree
3