Fisher & Paykel DD603IH Lockring Nut, Drain Cycle, Filter Plate, Drying Cycle, The Filter System

March 2004 Manual 599082

3.9.4Overheat Protection

The heater plate is only activated during the wash cycles. It is not used for drying. The temperature is maintained by the thermistor. If a failure occurs with the electronic control of the heater plate, overheat protection is effected by a thermal fuse on the heater plate itself.

The thermal fuse consists of a short length of solder in series with the dropper resistor track which will melt at a relatively low temperature, 268 – 302oC (514 – 576oF) causing the controllers power supply to go open circuit disconnecting power to the element.

3.10 Lockring Nut

The lockring nut holds the heater plate into the base of the tub and motor housing assembly to form a watertight seal. It does this by compressing two large ‘O’ rings between the heater plate and tub and between the heater plate and the motor assembly.

It has clips which hold the drain hose, fill hoses and the wiring loom in place.

Another function of the lockring nut is to support the wiring cover with three clips.

3.11 Drain Cycle

The drain pump is a self priming centrifugal pump which only pumps when the motor is rotating in the drain direction (anti-clockwise). It has a five bladed impellor pushed into a spline on the end of the rotor shaft.

The drain pump housing, which incorporates an inlet and outlet pipe, is welded to the motor housing, hence captivating the motor.

The inlet pipe plugs straight into the sump and is sealed there by a small ‘O’ ring.

The outlet pipe has a non return flap valve to prevent soiled water returning to the tub.

The drain hose is an extruded blow mould hose which is routed over the link assembly and exits out of the base of the product and is connected to a domestic drain.

The drain speed during the wash program is approx. 4200 rpm. In hardware output diagnostics test mode it is approx. 5000 rpm. This can account for draining OK in diagnostics but not during normal operation.

3.12 Filter Plate

The filter plate is a stainless steel disk which lies below the dish rack and spray arm and completely encompasses the base of the tub.

3.12.1 The Filter System

The tub is designed with vanes which swirl the water around and over the filter plate. At the front of the tub, located as part of the filter plate, is the drain filter. Large soils collect in the drain filter and only smaller soils flow through its micro mesh filter, eliminating re-depositing of soil during the wash. The drain filter should be regularly checked and cleaned.

3.12.2 Removing and Cleaning the Filter Plate

The drain filter can be emptied with the dish rack in place by removing the cutlery basket and opening the plastic section of the dish rack. The filter plate is removable for cleaning by removing the dish rack and spray arm and unlocking the lockring nut anti-clockwise.

3.13 Drying Cycle

Immediately after water from the final hot rinse has been drained from the tub, the drying system begins operation.

The drying fan draws air through from the vent in the rear of the tub, where it absorbs water from the dish load. The moisture laden air is then mixed with a larger quantity of ambient air (from the kitchen), to minimise the amount of vapour visible when exiting from bottom of the drawer front.

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