Zanussi 4 terminal interlock

SRU002807 Interlock

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Thermal/Pneumatic Interlock

Inside the 4 terminal interlock

This door interlock has a double safety system. The door is locked when power is applied and it is also locked when a level of water is in the machine.
The thermal delay device.
On powering the machine up a voltage is applied to a small heater inside the lock. The heat generated bends a bi-metal strip, first locking the door then applying power to the rest of the machine via an internal switch. When the machine finishes the program the heater power is removed, the bi-metal strip cools and releases the door.
The pneumatic device
As water fills the drum, air is displaced and forced through a hose and into the door interlock. A diaphragm expands mechanically locking the door. When the water is pumped away the pressure is released, the diaphragm contracts and the door is released

Terminals numbered from the bottom up
2 & 3 = Heater
4 & 5 = Switch
.

Common faults -
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1). Not locking (dead machine) a) Check the mechanical action of the door striker peg
b) Check for power on terminals 2 & 3
c) Replace the door lock

2). Not unlocking a) Check the machine is empty
b) Check for blockages in the pneumatic system
c) Replace the interlock

3). Slow to unlock a) Check for blockages in the pneumatic system.
b) Replace the door interlock.

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4). Slow to lock a) Check for power on terminals 2 & 3
b) Replace the interlock

sparesRus Home	Thermal/Pneumatic Interlock	Inside the 4 terminal interlock
	This door interlock has a double safety system. The door is locked when power is applied and it is also locked when a level of water is in the machine. The thermal delay device. On powering the machine up a voltage is applied to a small heater inside the lock. The heat generated bends a bi-metal strip, first locking the door then applying power to the rest of the machine via an internal switch. When the machine finishes the program the heater power is removed, the bi-metal strip cools and releases the door. The pneumatic device As water fills the drum, air is displaced and forced through a hose and into the door interlock. A diaphragm expands mechanically locking the door. When the water is pumped away the pressure is released, the diaphragm contracts and the door is released	Terminals numbered from the bottom up 2 & 3 = Heater 4 & 5 = Switch .
	Common faults -	Buy me on-line
	1). Not locking (dead machine)	a) Check the mechanical action of the door striker peg b) Check for power on terminals 2 & 3 c) Replace the door lock
	2). Not unlocking	a) Check the machine is empty b) Check for blockages in the pneumatic system c) Replace the interlock
	3). Slow to unlock	a) Check for blockages in the pneumatic system. b) Replace the door interlock.
Spares Shop	4). Slow to lock	a) Check for power on terminals 2 & 3 b) Replace the interlock