Information on the function of the oil heater

• The heater is screwed into the gear unit housing at the factory and is controlled by a thermostat. The set limit temperature on the thermostat below which the oil must be heated is set at the factory depending on the used lubricant.
• The switching point of the oil heater thermostat is factory-set to a temperature of about 5 K above the respective limit temperature for gear unit startup, see chapter Limit temperature for gear unit startup.
• At this temperature, the thermostat switches off the oil heater, see chapter Limit temperature for gear unit startup. Only then may the gear unit be started up. The thermostat activates the oil heater again once the temperature is approximately 5 K below the switching point.
• To prevent the oil from burning, the heating elements of the heater have a maximum surface load. This is why the heating process for cold gear unit oil can take between one and several hours. The exact duration of the heating process before the start varies depending on the gear unit size, design, mounting position, oil quantity, and ambient temperature.
• This is why the thermostat must be permanently supplied with power even if the drive is at standstill for a short time.
• If the drive is at standstill over a longer period and the thermostat is not energized, you have to make sure that the thermostat is energized in due time before the drive is started up.
• The thermostat and oil heater are installed in the gear unit and ready for operation. Prior to startup, wire and connect them properly to the current supply.
• Contact SEW‑EURODRIVE in the event of different viscosity classes or if ambient temperatures fall below the specified limit temperature.
• During installation, check the thermostat setting according to chapter Thermostat.