7 ABB Instruction manual
| MODVAR Low voltage reactive power
MODVAR
Low voltage reactive power compensation modules
4.1 Airflow and cooling requirement
The cross-section of air inlet and outlet must be adapted to
the air flow.
Air should flow from the bottom to the top of the cubicle as
illustrated on the opposite picture.
One fan per 6 MODVAR columns blowing a minimum air flow
of 525 m³/h is necessary.
Design guideline
The difference between ambient temperature outside the
cubicle and measured temperature must be lower than 10°C.
To meet that requirement, the temperature probe must be
located on top of the air duct.
The service conditions specified in the IEC 60831–1
section 4 are applicable.
As per IEC 60831-1 section 3.21, the ambient
temperature for capacitors is the air temperature
around the capacitors itself and not around the
cubicle.
Note: An over temperature protection device must
be fitted and set to 55˚C to protect the capacitors
against thermal stress.
Figure 4.2: MODVAR air flow direction
