Current Reduction; Current Reduction Depending On The Ambient Temperature On The 3Wl10 - Siemens SENTRON 3WL10 Manual

Application planning
4.1 Types of installation and installation locations
Installation altitudes
An installation altitude above 2000 m can result in higher temperatures on the switching
devices. The lower density of air can significantly reduce heat dissipation. The arcing
behavior and the conductivity of the density-dependent ionized gas mixture are also less
favorable at greater altitudes. This makes it necessary to decrease rated operational voltage
and the rated uninterrupted current.
Altitude [m]
Rated voltage 440 V [V]
Rated voltage 690 V [V]
Rated uninterrupted current [% I
Rated ultimate short-circuit
breaking capacity AC I
See also
Installation in the switchboard (Page 147)
4.1.5

Current reduction

4.1.5.1

Current reduction depending on the ambient temperature on the 3WL10

The circuit breaker itself has no derating within the application temperatures.
Current
rating I
[A]
630
800
1000
1250
Note
All values refer to the withdrawable breakers and fixed-mounted breakers and to the
conductor cross-sections stated in the table in Section Installation in the switchboard
(Page 147) and to the overriding standard IEC 60947.
The values do not apply to all mounting conditions for circuit breakers and may deviate
depending upon factors such as packing density, ventilation, internal separation of the
installation, etc.
Please observe the applicable overriding guidelines (e.g. IEC 61439).
142
n
[% I @U
cu cu
n < 40 °C
100%
100%
100%
100%
2000
440
690
] 100
100
]
e
Ambient temperature
45 °C 50 °C
100% 100%
100% 100%
100% 100%
100% 100%
3VA27 molded case circuit breakers & 3WL10 air circuit breakers
3000 4000
387 343
607 538
98 93
100 100
55 °C 60 °C 65 °C
100% 100% 100%
100% 100% 100%
100% 100% 100%
100% 100% 100%
Manual, 10/2018, L1V30499596002-01
5000
300
470
90
100
70 °C
100%
100%
100%
100%