11
INSTALLATION AND MAINTENANCE
LSA R 49.1 Air/air heat exchanger
ALTERNATORS - Ex II 3 G
SERVICING - MAINTENANCE
4081 en - 09.2006 / a
LEROY-SOMER
4 - SERVICING - MAINTENANCE
4.1 - Safety measures
Servicing or troubleshooting must be carried out strictly
in accordance with instructions so as to avoid the risk of
accidents and to maintain the machine in its original
state.
All such operations performed on the alternator should
be undertaken by personnel trained in the
commissioning, servicing and maintenance of electrical
and mechanical components.
Before any intervention on the machine, ensure that it cannot
be started by a manual or automatic system and that you
have understood the operating principles of the system.
4.2 - Regular maintenance
4.2.1 - Checks after start-up
After approximately 20 hours of operation, check that all fixing
screws on the machine are still tight, plus the general state of
the machine and the various electrical connections in the
installation.
4.2.2 - Exchanger
4.2.2.1 - Primary Circuit (hot air)
The air to be cooled flows through the machine and through
the exchanger in a closed system. The air circulation is
generally ensured by a ventilator locked onto the machine
axle and situated on the front bearing side. In particular cases
(variable speed ...) the air circulation is ensured by a moto-
ventilator mounted on the exchanger casing.
4.2.2.2 - Secondary Circuit (cold air)
Ambiant air is usually used for cooling. The circulation
through tubes is ensured ; either by a turbine mounted
overhanging the back of the machine on a bearing extension
or by a moto-ventilation mounted on the exchanger. In order
to prevent excessive overheating caused by the tubes
clogging up, it is adviseable that the stator coil be monitored
with thermal detection probes (PTC or PT100).
4.2.2.3 - Performances
We guarantie that the performance of the exchanger
complies with the definitions agreed upon. (ambiant
temperature, power to be evacuated, environmental
conditions, loss of charge etc.).
4.2.3 - Manufacture of the exchanger
The exchanger casing is made from steel sheets. The
network of tubes is generally composed of aluminium alloy or
steel tubes. The ends of the tubes are fitted to steel panels.
4.2.4 - Exchanger maintenance
If the coolant is used in a clean atmosphere it can run for
several years with no maintenance. If the atmosphere is
polluted (dust, sand, greasy vapours etc.) the tubes must be
cleaned regularly. Clogging of the tubes becomes noticeable
when the thermal exchange performances are reduced and
the air in the primary circuit overheats causing the machine to
also overheat ; therefore, machine overheating indicates that
the exchanger is probably dirty.
4.2.5 - Bearings
The bearings are greasable. It is advisable to lubricate the
machine during operation. The lubrication characteristics are
given in the table below.
Lubrication intervals are given for grease type :
LITHIUM - standard - NLGI 3.
The factory lubrication is performed with grease :
ESSO UNIREX N3.
Before using another grease, check for compatibility with the
original one. Monitor the temperature rise in the bearings,
which should not exceed 60°C above the ambient
temperature. Should this value be exceeded, the machine
must be stopped and checks carried out.
4.2.6 - Electrical servicing
Cleaning product for the windings
Do not use : trichlorethylene, perchlorethylene, trichloro-
ethane or any alkaline products
.
Certain strictly defined pure volatile degreasing agents can
be used, such as :
- Normal petrol (without additives); inflammable,
- Toluene (slightly toxic); inflammable,
- Benzene (or benzine, toxic); inflammable,
- Ciclohexare (non toxic); inflammable.
Bearings
6322/C3
6320/C3
Quantity of grease : gr or cm
3
50
60
Lubrication interval : hours
4500
4500
WARNING
WARNING