Monday, November 23, 2015

Fisher and Paykel Dish-Drawer DD603HM - DD603IH - Troubleshooting

Fisher & Paykel DD603 - DD603H - DD603I - DD603IH - DS603 - DS603H DS603 I - S603IH - DD603M DD603HM - DS603M - DD603H - Dish-Drawer Troubleshooting
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-galvanized material called Galvoclean.
Unlike most other dishwashers, the chassis assembly is a load carrying structure designed to impart stiffness to the product and to ensure deflection is minimized.
The feet of the Double cabinet are assembled into the chassis by means of four steel inserts which are clinched in place to form a permanent threaded connection.  The tub extends 520mm (2015/32”) out of the cabinet by travelling along two rigidly attached slides on either side of the tub.
Drawer Fronts
Pre-finished 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 which 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.
Electronics
In the DD603/ DS603 (Phase 3) electronic controller the functions of controlling the motor as well as controlling the user interface console have been combined into a single 16-bit Micro Controller on the main printed circuit board.  This Micro controller also controls a transformer less 85w switch mode power supply. This power supply utilizes a large dropping resistor on the heater plate in conjunction with phase control of the mains voltage in order to produce a variable voltage rail. From this the controller can supply voltages from 5V to 85V to the various components in the Dish Drawer.
NOTE:- With power supplies of this nature all components regardless of supply voltage should be treated as live to earth. i.e = 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 effected by a short length of solder in series with the dropper resistor track on the heater plate. In an overheat situation this solder melts causing the power supply to go open circuit.
Tub Home Sensor
A tub home sensor is used to determine when the tub is closed and it is safe to start a cycle. The tub home sensor consists of an inferred LED (sender) and an inferred transistor (receiver) mounted on the circuit board in the controller. Inferred light is  transmitted from the LED through an optical light pipe to the right hand side of the tub. The inferred receiving transistor also has an optical light pipe leading from it out to the side of the tub. When the tub is closed the two light pipes are optically connected via a prism mounted in the trim on the side of the chassis.
Touch Switches
Two touch switches are used on the secondary control panel one to select the required wash cycle and one to turn the Eco option on or off. They are capacitive touch switches and are supplied with an analogue signal from the controller that will change in the presence of an earthed mass (i.e. customer’s finger).

Motor
The motor is a fully electronically controlled 80V, 60w, 3 phase, 6 pole brushless DC motor, running on wash at between 2300-2850rpm depending on the cycle selected and at approximately 4200 rpm on Drain.
Rotor
The rotor is a four pole permanent magnet rotor with a graphite bearing at each end of the vertical shaft. At the lower end of the rotor shaft is the drain impellor and at the upper end is the wash impellor.
Spray Arm
The spray arm is shaped for most efficient water flow. The holes are positioned for best penetration into the wash load, with the water jets angled to ensure the spray arm rotates at the most efficient speed. There is a flap valve moulded into the top of the spray arm. This part lets air through the spray arm when the Dish Drawer is filling with water. The Dish Drawer fill levels are more consistent with the flap valve system.
Wiring Cover
The wiring cover protects the customer from all electrical components in the motor area underneath the tub. All electrical components regardless of voltage should be treated as live with respect to earth. It also serves to protect the motor assembly, drain and fill hoses from damage when opening and closing drawers. The wiring cover acts as a cosmetic part of the product.
Lid System
Lid Operation
The lid is a single piece of polymer plastic with a static seal co-injection moulded into it. Each side of the lid is clipped into a yoke which is in turn connected to a worm drive lid actuator assembly containing a small brushed DC 24V motor.

When Activated
At the beginning of each wash cycle, both motors are powered for approximately 10 seconds, which pulls the lid down onto the tub in approx 5 seconds. The lid remains down for the duration of the cycle and is only lifted when the Dish Drawer beeps to signal the end of the cycle or if the customer pauses it to gain access to the tub.
During a Power Failure
If power to the Dish Drawer fails with the lid down you can still force the tub open manually if access is required. It is very difficult however to close the tub again without lifting the lid. The lid can be wound up manually with the tub fully removed. Failure to raise the lid before closing the Drawer could result in the lid seal being damaged.
Tub.  The tub is the main cavity where all the wash activity occurs. The tub is a polymer plastic receptacle which has a wash pump and spray arm at the base. The tub also has guide vanes around its walls which direct falling water from the wash cycle in a clockwise direction around the filter plate. This clears the filter plate of food particles into the sump where they can be trapped or pumped out during the drain cycle.
Filling
Water Inlet
The tub of the Dish Drawer fills by a single water inlet hose, hot water connection for USA and Japanese products and cold water connection recommended for the Australasian/UK/ Europe products. From the connection to the water supply in the kitchen, the inlet hose enters the cabinet of the dishwasher at the base, onto a dual water valve.  Each tub is supplied water independently via one of the dual valve coils and a fill hose that runs through a customized link assembly at the back of each tub and travels along the base of the tub under the wiring cover to the front. At the front of the tub, the fill hose connects to the detergent dispenser which allows water to enter the tub, firstly through the pre rinse section of the dispenser for the pre rinse cycle and secondly through the main wash section for all other cycles.  In a product fitted with a water softener, water is directed through the softener before entering the dispenser.
Dispensing Detergent and Rinse-aid
The dispenser is mounted in the front wall of the wash tub.  The detergent dispenser consists of two detergent chambers, one for pre wash and the other for the main wash.  The detergent dispenser door is opened manually for detergent loading and then manually closed ready for the detergent to be transported to the wash tub by the inlet water. To enable each detergent chamber to be dispensed separately, an inlet water diverter valve controlled by the electronics is required.  Additionally a positive displacement pump unit and storage tank are incorporated within the dispenser to supply rinse aid. The rinse aid dispensed volume can be adjusted by the customer in option adjustment mode. A glowing red light on the tank filler cap indicates an empty rinse aid tank.
Amount of Water
The tub fills with approximately 2.5 liters / 0.8 US gallons of water, approximately level with the base of the spray arm. Once this level is reached, the wash pump (which has sensed the fill via the electronics) becomes primed and pumps the water through the spray arm which will then rotate. The load on the wash pump is constantly monitored throughout the wash cycle and the water level adjusted if necessary.
Heating
The Element
The heater plate is an element consisting of porcelain enameled steel plate with a thick film resistive circuit printed onto the dry side. As well as the heating circuit a large dropping resistor is also printed onto the heater plate which forms part of the controllers power supply. The element is clamped in place by a locking nut and supports the motor at the base of the tub.
Heating the Water
The heater plate lies beneath the filter plate. A flow through water heating system is created during the wash cycle by allowing water to flow through the filter plate, over the surface of the element and into the wash pump.
Maintaining the Temperature
Attached to the element is a sub printed circuit board with a temperature sensitive thermistor. This connects by means of a RAST 2.5 connector system to the wiring harness of the element. Sensor components are unserviceable and if they fail a new heater plate is required.
Overheat 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.
Lockring Nut
The lock-ring 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 locking nut is to support the wiring cover with three clips.
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.
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.
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.
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.
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 minimize the amount of vapor visible when exiting from bottom of the drawer front.  The fan runs continuously during the drying cycle and will restart if the tub is opened and closed again. After the wash program is complete, the lid drives up, and the fan continues to run for 30 minutes, but will not restart if the tub is opened.
Water Softener (where fitted)
The Water Softener uses a softening material (resin) to prevent most of the elements that cause hard water from being present in the wash water. The resin can only treat a limited amount of water before it needs to be regenerated. Regeneration is achieved by pumping salty water (brine) through the resin, and flushing away the hard elements to the drain. The process of delivering softened water and regeneration is controlled by the Electronic Controller.  Delivering Softened Water:- Supply water arrives from the inlet valve. In the water softener it passes through a piper interrupter (air break) and a diverter valve. It is then either directed through the resin to the dispenser, or directly to the dispenser, then into the tub. The electronic controller measures the volume of water treated, and adds an appropriate amount of non-treated water, to deliver a mix which is at the required hardness according to a predetermined schedule. Water is treated according to its supply hardness. The customer is able to select one of 5 settings in option adjustment mode.  Regeneration:- Regeneration is triggered when the amount of water that has been treated since the last regeneration nears the capacity of the Water Softener. The quantities treatable for each of the 5 settings of supply hardness have been predetermined, and are stored in the electronic controller. When triggered, immediately after filling for the main wash, the brine pump is activated and delivers a volume of salty water into the resin, at an amount appropriate to the hardness setting. When the wash cycle finishes, the resin is flushed with supply water, and the by-products of regeneration are delivered into the wash water, and drained with it away to waste. Normal treatment of incoming water then resumes.  Salt:- the customer is required to fill the salt tank with dishwashing salt from time to time. Salt is used in the water softener by mixing it with water to produce the salty water (brine) used in regeneration. When the salt level is low, a salt level detector causes a glowing red light to appear in the salt bung, and a “Salt” symbol appears in the LCD.  When this happens, the customer should remove the salt bung, and using the salt container provided, pour salt into the salt reservoir until salt can be seen at the opening. The “Salt” symbol on the LCD will disappear and the red light will not be visible when the salt tank bung is replaced. In areas where the supply water is moderately hard (21 dH – degrees of hardness, 375ppm – parts per million, Water Softener Setting 3) the salt reservoir will need to be filled about once a month, and in harder areas more frequently. Delivery of treated water from one fill of the salt reservoir:
240 litres at 30 – 100 ppm from 375 ppm supply water
144 litres at 30 – 100 ppm from 625 ppm supply water
OPTION ADJUSTMENT MODE – FAULT DIAGNOSIS & FAULT CODES => By next post: