SOI/DT 2010-03 dmm 54/78 599 72 84-41
11.9 Universal motor (EWM 21xx)
11 Tachometric generator
12 Stator
13 Thermal cut-out
14 Rotor
20 PCB
11.9.1 Power supply to motor
The PCB powers the motor via a triac; the direction of rotation is reversed by switching the contacts on the two
relays (K2-K3), which modify the connection between the rotor and the stator.
In certain models, a third relay (K4) is used to power the stator (full or half field) according to the spin speed.
The speed of rotation of the motor is determined by the signal received from the tachometric generator.
During the spin phases, the micro-processor performs the anti-foam
and the anti-unbalancing control
procedure.
11.10 Three-phase asynchronous motor (EWM 25xx)
11. Tachometric generator.
20. Main circuit board
23. Inverter
24. Motor
X-Y-X = Motor windings
11.10.1 Power supply to motor
Three-phase power is fed by the inverter (4), which sends through the connectors 5-6-7 the three phases to
connectors 1-2-3 on the motor (nodes U-W-V), where the windings (Y-X-Z-) are connected.
The phase shift between the phases is 120° and peak amplitude is 310V.
It is possible to get an idea of the efficiency of the
motor by measuring the resistance of the coils:
Winding y ohm 5,4
∼ ±7% (contacts 2-3)
Winding x ohm 5.4
∼ ±7% (contacts 1-2)
Winding z ohm 5.4
∼ ±7% (contacts 1-3)
Winding T (tachometric) ohm 121
∼ ±7% (contacts 4-5))
Any work on electrical appliances must only be carried out by qualified
technicians.
Unplug the appliance before accessing internal components.
When replacing the “INVERTER” board, do not open the plastic casing, because
some parts are subject to high voltage values and some condensers remain
loaded for a long time at dangerous voltage levels even after being unplugged.
Accidental physical contact may cause electric shocks.
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