ABB UniGear 500R - Operating Condition

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2.4 Operating condition
2.3.1. Normal operating conditions
The switchgear is basically suitable for normal
operating conditions for indoor switchgear in
accordance with IEC 62271-200. Among other
considerations, the following limiting values apply:
Ambient temperature:
Maximum
+ 40 °C
Maximum 24 h average
+ 35 °C
Minimum (according to “minus 5 indoor class”)
- 5 °C
Ambient humidity:
Maximum 24 h average of relative humidity
95% RH
Maximum 24 h average of water vapour pressure
2.2 kPa
Maximum monthly average of relative humidity
90% RH
Maximum monthly average of water vapour pressure
1.8 kPa
The normal operational altitude is up to 1000 m above
sea level. The indoor ambient conditions are free of
significant pollution, such as dust, smoke, corrosive
and/or flammable gases, vapors or salt, etc.
2.3.2. Special operating conditions
The switchgear is suitable for operation in the WDa
type of climate according to IEC 60721-2-1.
Special operating conditions must be discussed with
ABB in advance. For example:
 At site altitudes above 1000 m, the effects of the
reduction in dielectric strength of the air on the
insulation level must be taken into account (Figure
1).
 Increased ambient temperatures must be
compensated in the design of the busbars and
branch conductors, otherwise the current carrying
capacity will be limited.
Note on special climatic operating conditions:
When switchgear is operated in areas with high
humidity and/ or major rapid temperature fluctuations,
there is a risk of dew deposits which must be excluded
under normal operating conditions for indoor
switchgear. Preventive action (e.g. suitable ventilation
and proper air conditioning of the building or housing,
use of dehumidifying equipment, etc.) must be taken
into consideration with ABB to avoid this condensation
phenomenon and any resulting corrosion or other
adverse effects.
Figure 1: Curve for determining the altitude factor k in
relation to the altitude H.