Webasto Thermo 230 Installation Instructions Manual page 54

To install the circulating pump
5.5. Motor for the U 4851 / Aquavent 6000 S circulating pump
The U 4851 / Aquavent 6000 S circulating motor is fitted with a brushless
motor.
5.5.1. Soft start
The motor starts slowly to protect its material.
It does not reach its maximum speed for approx. 5 seconds.
5.5.2. Dry running protection (U 4851 only)
A dry running protection is integrated in the motor
for speeds >3300 rpm.
If the motor consumes less than 4 A of current in a timeframe of 1018
revolutions, it assumes that it is running dry. The motor is switched off
by the error motor (after approx. 10 seconds of operation or approx.
15 seconds after it was switched on).
5.5.3. Blocking protection
If the speed falls to below 57 rpm the motor is switched off after approx.
1 second by the error mode. If the motor does not complete a full
revolution in 1 seconds despite the medium flow, it is also switched off
by the error mode.
5.5.4. Error mode
The error mode switches off the motor in the event of faults. The motor
is switched to power-saving sleep mode by the error mode after approx.
5 seconds.
5.5.5. Sleep mode
In sleep mode the internal consumers of the motor's electronics are
switched off. The current consumption in this mode is then < 2 mA.
50
Thermo 230/231/300/301/350
5.5.6. To reactivate the motor
The motor can be reactivated from sleep mode. This is done by
disconnecting it from the power supply for approx. 2 minutes. When the
voltage supply is reconnected the motor will restart in soft start mode.
5.5.7. Reverse polarity protection
The motor does not have polarity reversal protection. The motor is
protected from polarity reversal by the wiring harness and a 25 A fuse.