Technical Overview; Chassis; Drawer Fronts; Electronics - Fisher & Paykel DishDrawer DD24D Series Service Manual

3

TECHNICAL OVERVIEW

1.1

Chassis

The DishDrawer™ chassis is one complete assembly composed of 5 steel metal components
locked together by a proprietary riveting process. The chassis exterior is made of a lacquered
electro-galvanised material.
Unlike most other dishwashers, the chassis assembly is a load carrying structure designed to
impart stiffness to the product and to ensure deflection is minimised.
The feet of the double cabinet are assembled into the chassis by means of four steel inserts that
are clinched in place to form a permanent threaded connection.
The tub extends 520mm (20
on either side of the tub.
1.2

Drawer Fronts

Prefinished drawer fronts are formed from a painted, brushed or Iridium finish stainless steel blank.
The drawer fronts are attached to the tub by means of formed hooks and two pins that are inserted
through either side of the tub.
On the integrated model, the front panel supplied on each drawer is the mounting panel for the
joinery finished drawer front. The joinery finished drawer front is supplied by the customer.
3.1

Electronics

In the DD24 / DD60 (Phase 6) electronic controller, the functions of controlling the motor as well as
controlling the user interface console are combined into a single 16-bit micro controller on the main
printed circuit board.
This micro controller also controls a transformerless 85w switch mode power supply. This power
supply utilises a large dropping resistor on the heater plate in conjunction with phase control of the
mains voltage in order to produce a variable voltage supply for the motors, solenoids and drying
fan. From this the controller can supply voltages from 5V to 85V to the various components in the
DishDrawer™.
A separate 24volt dc power supply on the PCB mains filter board (located within the mains filter
housing in the lower left corner of the chassis) supplies power to the microcontroller and LEDs in
the electronic controller.
An isolation relay is mounted on the PCB mains filter and will disconnect power to major
components when signalled to by the controller under certain fault conditions. Once the fault has
been cleared, it will require the power to be disconnected from the product for the isolation relay to
reset.
NOTE: - With power supplies of this nature, all components, regardless of supply voltage,
should be treated as live to earth, i.e. at supply voltage.
The user interface comprises a printed circuit board for front controls and a touch switch panel for
internal controls.
The electronics can connect to a computer service tool via an optical light pen for fault finding and
product information.
The element is switched by one single pole relay. Overheat protection is provided by a thermal
fuse in series with the water heater track on the heater plate. In an over-heat situation, this gravity
fuse drops off and disconnects the water heater element from the supply voltage.
A non-serviceable fuse is mounted within the controller to provide additional safety protection.
15
/ ") out of the cabinet by travelling along two rigidly attached slides
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599735A