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8.6 Cycling thermostat
°
1 - Terminal of 110
N.C. safety thermostat
°
2 - Terminal of 82
N.C. automatic reset functional thermostat
3 - Bimetal
4 - Contact
C - Terminal not used
General features:
The thermostats regulate and control the air temperature inside the appliance.
They are bimetal, with fixed temperature values.
When the bimetal disk (3) reaches the temperature at which the
thermostat has been set, it clicks and through a rod (represented by the
arrows in the picture) it opens the contact (4). During the cooling phase
the bimetal returns to its starting position.
In this appliance are used two thermostats (fitted into one casing), which have two different intervention
temperatures and are normally closed (N.C.).
The functional thermostat (cycling) refers to terminal (2), intervenes at 82°, and resets at 70°.
The safety thermostat refers to terminal (1), intervenes at 110° and when it intervenes cannot be reset
anymore.
Checking the efficiency:
The efficiency of the thermostat can be checked by using a tester (ohm scale).
Measure the resistance between contacts 1-2, its value must be near.
8.7 Motor unit
1 – Fan (with inclined paddles cold air circulation)
2 – Belt stretcher
3 – Motor
4 – Fan (with straight paddles warm air circulation)
General features:
The motor assembly consists of a belt stretcher (2), two fans (1-4 respectively for the cold air circulation
and warm air circulation fitted to the motor shaft with nuts) and single-phase asynchronous motor (3)
provided thermo-amperometric safety cut-out.
The single-phase asynchronous motors are characterized by absence of initial starting torque, which is
obtained by the addition of an auxiliary winding which is phase-shifted 90° with respect to the primary
winding. The 90° phase shift is obtained by an 8µF or 9 µF capacitor connected in series with the winding.
The stator consists of two identical windings, with a 90° phase shift; depending on the way in which they
are connected, through the timer inverter circuits, these behave either as primary windings or as start-up
windings.
Warning: while assembling the motor fans do not invert them otherwise there are malfunctions in
the air circulation inside the dryer.
Checking the efficiency:
It is possible to check the efficiency of the motor by measuring the windings resistance:
Winding A
ohm 29
~
Winding B
ohm 29
SOI/DT 2002-07 dmm
~
(contacts 1-3)
(contacts 2-3)
14/55
WIRING DIAGRAM
599 35 38-32
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