INSTALLATION, USE AND MAINTENANCE MANUAL
EN
14
15
INSTALLATION, USE AND MAINTENANCE MANUAL
EN
6.4 – VENTILATION
6.4.1 – NATURAL / FORCED VENTILATION OF THE
INSTALLATION ROOM
A
1
=
P
0,1 x √(Hx(dt)
3
)
A
2
= 1,1 x A
1
A
2
A
1
B
owers Electricals Ltd, Heanor Gate Road, Heanor, Derbyshire DE75 7GX
Telephone: 01773 531531 (24 hours) Fax: 01773 716171
E-mail:
www.bowerselec.co.uk
B
owers Electricals Ltd, Heanor Gate Road, Heanor, Derbyshire DE75 7GX
Telephone: 01773 531531 (24 hours) Fax: 01773 716171
E-mail:
www.bowerselec.co.uk
For optimal use of the transformer’s full rating, it is essential that the
losses (heat) produced by the core and the windings are effectively
removed. The installation room must be ventilated well in order to
guarantee stable operation and the expected service life of the
transformer. Obstructions around the transformer or close to the
enclosure ventilation openings restricting natural airflow must be avoided.
In order to guarantee standard service conditions and to prevent the
transformer from exceeding its temperature limits, it is necessary to
install air louvers in the installation room. The air louvers must be
located on 2 opposite walls (one in the bottom part and the other in the
upper part) and be big enough to dissipate the heat generated by the
transformer during the service.
Figure 8 – Natural ventilation of the installation room
The minimum size of the openings to guarantee sufficient airflow inside
the installation room (considering average annual temperature of 20°C)
can be calculated using the following formulae:
A
1
= lower opening surface (m²)
A
2
= upper opening surface (m²)
P = total no load losses / load losses at 120°C (kW)
H = difference in height between the top opening and the central line of the
transformer (m)
dT = temperature difference between incoming and outcoming air
temperature of the room (C°)
In case the natural ventilation is not sufficient, the openings may be
equipped with fans in order to increase the airflow inside the installation
room. In air-conditioned rooms, to avoid water condensation and possible
damage of the transformer, it is highly recommended not to blow the fresh
air directly on the transformer.
6.4.2 – FORCED VENTILATION OF THE TRANSFORMER
Forced cooling is necessary in the following cases:
• Short-time overloadings
• Low-dimensional room
• Scarcely ventilated room
• Medium daily temperature higher than 30°C
Figure 9 – Forced ventilation of the installation room
A
2
A
1
6.4 VENTILATION
6.4.1 NATURAL / FORCED VENTILATION OF THE INSTALLATION ROOM
For optimal use of the transformer’s full rating, it is essential that the losses (
heat
) produced by the core and the windings
are effectively removed. The installation room must be well ventilated, in order to guarantee stable operation throughout the
expected service life of the transformer. Obstructions around the transformer or close to the enclosure ventilation openings,
restricting natural airflow, must be avoided.
In order to guarantee standard service conditions, and to prevent the transformer from exceeding its temperature limits, it may
be necessary to install air louvres in the installation room. The air louvres must be located on 2 opposite walls (one in the bottom
part and the other in the upper part) and be big enough to dissipate the heat generated by the transformer during the service.
The minimum size of the openings to guarantee sufficient airflow inside the installation room (considering average annual
temperature of 20°C) can be calculated using the following formulae:
A1 = lower opening surface (m²)
A2 = upper opening surface (m²)
P = total no load losses / load losses at 120°C (kW)
H = difference in height between the top opening and the central line of the transformer (m)
dT = temperature difference between incoming and outcoming air temperature of the room (C°)
In case the natural ventilation is not sufficient, the openings may be equipped with fans in order to increase the airflow
inside the installation room. In air-conditioned rooms, to avoid water condensation and possible damage of the transformer,
it is highly recommended not to blow fresh air directly on to the transformer.
3
INSTALLATION, USE AND MAINTENANCE MANUAL
EN
APPENDIX
1.0 – REFERENCE STANDARDS
2.0 – RATING PLATE
3.0 – LIST OF COMPONENTS AND ACCESSORIES
4.0 – IMPORTANT NOTICE
5.0 – RECEIVING, HANDLING AND STORING
5.1 – RECEIVING
5.2 – HANDLING
5.3 – STORAGE
6.0 – INSTALLATION
6.1 – SITE PREPARATION
6.2 – STANDARD INSTALLATION CONDITIONS
6.3 – WORKING TEMPERATURE
6.4 – VENTILATION
6.4.1 – NATURAL / FORCED VENTILATION OF THE
INSTALLATION ROOM
6.4.2 – FORCED VENTILATION OF THE TRANSFORMER
6.5 – INSULATION DISTANCES
6.6 – SAFETY DISTANCE
6.7 – TIGHTENING TORQUE FOR ELECTRICAL & MECHNICAL
CONNECTIONS
6.8 – VISUAL INSPECTION
B
owers Electricals Ltd, Heanor Gate Road, Heanor, Derbyshire DE75 7GX
Telephone: 01773 531531 (24 hours) Fax: 01773 716171
E-mail:
www.bowerselec.co.uk
CAST RESIN TRANSFORMER:
Installation, Operation &
Maintenance Manual
Tel: 01773 531531 [email protected] www.bowerselec.co.uk
13
