Whirlpool WED99HEDW0 Technical Education page 8

GENERAL INFORMATION
General Theory of Operation (continued)
HybridCare™ Heat Pump Dryer New Components
Relay Expansion Board (REX) – a circuit board has been added (located next to the CCU) to switch on and off the auxiliary fan
that is used to cool the post condenser and compressor electronics.
Auxiliary Fan – used for cooling the compressor components and begins the cooling of the refrigerant in the post condenser.
Drain Pump – to drain water in the sump collected from the evaporator. The drain pump is connected to P8 on the CCU, (which
was used previously to energize the spray valve).
Figure 11 - Wiring Diagram.
Float Switch – has two positions. The first (lower) position signals the CCU to activate the drain pump to remove water from the
sump. The second (full) position signals the CCU to stop the dryer and generates the F9E1 error code (drain system error).
Reed Lint Switch – is a magnetic reed switch that signals the CCU when the Evaporator Lint Filter is not installed. The dryer will
not operate if the Evaporator Lint Filter is not detected.
HybridCare™ Heat Pump Dryer Block Diagram
The HybridCare™ Dryer is not unlike its predecessor—the Whirlpool Duet direct-drive dryer (aka Alpha). Most of the components
used in the Whirlpool direct drive dryer are also used in the new HybridCare™ dryer. Think of the compressor as the second heater.
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1-4 HybridCare™ Dryer with Heat Pump Technology
FOR SERVICE TECHNICIAN'S USE ONLY
Figure 2 - Block Diagram