Theory of Operation
The design of the washer-extractor emphasizes performance reliability and long service life. The cylinder, shell, and main body panels are fabricated of stainless steel.
Electrical controls for the washer-extractor are housed in a separate enclosure located on the top of the machine. Removing the screws from the module cover, lifting the cover, and pulling to the rear provides access to the control module. This module contains the WE-6 control, contactors, water-level switch, and other control components.
The cylinder is driven by a V-drive system supported via the shaft by two flange-mounted spherical roller bearings bolted to the A-frame.
The cylinder is constructed with four lifters or ribs that lift the laundry from the bath solution when the cylinder rotates at slow speed and then allow the laundry to tumble back into the bath. This mechanical action accomplishes the washing function. The cylinder is perforated, allowing the water to drain from within during the wash and extract steps.
The spray rinse feature consists of a fiber-reinforced clear hose connected to the center of the door glass and to both a hot and cold water inlet valve. A hemispherically-shaped spray nozzle inside the door glass produces a fan-action water spray which disperses rinse water throughout the load.
All UWPV washer-extractors use an AC inverter drive control which provides seven preset motor speeds using a single motor. The AC drive interface board converts motor logic from the WE-6 control to the correct signals for the AC inverter drive. In addition, all logic inputs to the control are routed through this board.
The operator can select from among 39 preprogrammed cycles. Cycle 39 is a test cycle used to verify proper operation of the washer-extractor. With the exception of Cycle 01, the remaining cycles are complete wash cycles or specialty cycles designed to handle various fabrics at specific water temperatures and levels. Cycle 01 is designed to test an external chemical injection supply system.
Programmable custom cycles are another feature of the UWPV.
The vibration switch system utilizes a micro-switch mounted between the faces of the A-frame to signal the WE-6 control that the load imbalance is too great for high extract speeds. Depending on the design series, the vibration switch will perform in either of two ways. If the washer-extractor utilizes ONLY the
Operation
vibration switch to detect an out-of-balance load, the switch will signal the WE-6 control to slow the motor speed, allowing the load to re-distribute, and then resume the spin speed programmed. The control will attempt to redistribute the load in this manner up to three times. On the third attempt, if an imbalance condition is still detected, the control will abort the spin speed step(s) and advance to the next non-spin speed step.
However, if the washer-extractor is equipped with BOTH the vibration switch and the AC inverter drive balance detection systems, the function of the switch is slightly different. The inverter drive will monitor load imbalance conditions and the control. If the load is not balanced to spin at the programmed spin speed, control will attempt to re-distribute the load. After three unsuccessful attempts to balance the load, control will limit the spin speed (on models with the WE-6 Firmware ID Code of “ARWCxx” the WE-6 display will alternately flash the programmed spin speed and the substituted spin speed). During the spin step, if the vibration switch detects a severe imbalance, due to improper installation or improper loading of the washer, the control will abort the remaining portion of the cycle and stop the machine. The display will flash “BAL/DR” while aborting the cycle until the door has been opened.
Water enters the washer-extractor through electromechanical water valves controlled by the microcomputer. The microcomputer also controls the drain and the door lock. In addition, it selects the water levels according to the programmed cycle. Vacuum breakers are installed in the water-inlet plumbing to prevent backflow of water.
The standard production UW35PV and UW60PV use a single drain valve. (Dual drains are available as an option.) The UW80PV, UW100PV, UW125PV and UW150PV use dual drain valves. The dual drains open and close together under control of the WE-6 control. The drain valve is normally open, which means that it closes only when power is applied, thus allowing the machine to drain in the event of a power failure.
A door-lock system prevents opening of the stainless steel door when a cycle is in progress. It also prevents operation of the washer-extractor when the door is open. The door box contains the door-lock microswitch, door-closed magnetic switch, and the door-unlock solenoid.
On later design models equipped with a rotation sensor, the door lock system will allow door to unlock soon after basket stops at the end of the cycle.