Before starting the gear unit ensure that all the relative connections have been made
properly.
It is also advisable to check the connection cross section periodically to ensure that it is free from
sediment and/or obstructions that could impair the efficiency of the external cooling system. If
necessary, clean the circuit by flushing with a suitable chemical agent, checking with the manufacturer
that the cleaning agent is compatible with the construction material of the coil.
Pay the maximum attention when using hazardous chemical detergents and take all the
necessary precautions to ensure they are disposed of in compliance with the law.
The interval for checking the condition of the coil and any maintenance work depends on the
characteristics of the cooling water used (refer to maintenance heading).
Any defects of the coil can be identified by observing the condition of the lubrication oil in the gear unit,
which will display a high degree of foaming if it has become contaminated with water.
7.1.3 OIL HEATER
With significantly low ambient temperatures resulting in increased oil viscosity and preventing correct
flow, for example, in the following cases:
operation at temperatures below 0°C
starting of gear units featuring oil bath and splash lubrication if the minimum ambient
temperature is not at least 10°C higher than the oil drop point.
starting of gear units with forced lubrication when the oil viscosity is higher than 1800 cSt
(depending on the lubricant utilised this value is reached at ambient temperatures between
approximately 10°C and 20°C)
To remedy this situation the gear unit can be equipped with an electric heater and a minimum
temperature thermostat.
The heater is fitted directly in the gear unit sump under the oil level.
Before removing the heater the gear unit must be drained of oil.
If a single heater is insufficient to heat the oil to the minimum required temperature, or if shorter warm-
up times are required, consult Bonfiglioli's Technical Service.
The thermostat is set to 25 ± 5°
C. The electrical circuit connected to the thermostat must be set up in
such a way that the heater is disconnected once the cut-out temperature has been reached.
All electrical connections are to be made by the customer prior to starting of the gear unit.
The heater must remain disconnected during periods in which the gear unit is not in use: the
heater must be switched on before the gear unit is started, only when it is completely immersed in the
oil, and exclusively for the time required for the oil to reach the minimum specified temperature.
The use of the heater for longer periods than specified above can result in carbonisation of the oil
molecules, thus impairing lubrication performance and producing residues that are harmful to the gear
unit and its components.
In the presence of forced lubrication, if the circuit components, such as the connecting pipelines,
pump, etc., are exposed to freezing temperatures, they must be equipped with a heating system to
allow correct oil circulation.
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