Heat Pump Operation; Heat Pump Heater Terminal Cover - Bosch SHEM63W55N Repair Manual

Design and function
¡ 3-pin motor terminal at the end of the motor.
Fig. 11: Heat pump terminals
1 6-pin heater terminal
2 3-pin motor terminal
Ratings: 3-pole BLDC, 110 - 120 VAC, 150 Hz, 1200 W thick film heater, < 80 W mo-
tor, class F insulation, 5-blade impeller with guide wheel.

3.3.2 Heat pump operation

The impeller draws water into the pump and circulates it inside the cylindrical heating
element. The guide wheel directs the water through the pump outlet to the water switch
to be directed to the spray arms.
Fig. 12: Heat pump detail
1 Outlet to water switch
2 Heating cylinder w/ NTC's
3 BLDC motor
2020-04-24_58300000218396_ara_en_c
4 Impeller
5 Guide wheel
6 Inlet from sump
7 Pump housing
While water is being circulated, the BLDC (Brushless DC) motor senses the pump
status based on the current (amp) draw of the motor windings:
¡
No water
¡
Too little water (cavitating)
¡
Proper water level
¡
Pump blockage
Safety-related issues, such as "heating without water" or "water too hot", are detected
and evaluated.
If the pump is blocked, the pump tries several times to loosen the blockage. If unsuc-
cessful, the wash cycle ends and an error code is stored in memory.

3.3.3 Heat pump heater terminal cover

Starting FD 0004 (April, 2020), all dishwashers include heat pump heater terminal cov-
ers to meet new UL requirements. If lost, they are available separately and are easily
snapped onto heat pump heater terminals.
Fig. 13: Heater terminal cover (top view)
Fig. 14: Heater terminal cover (bottom view)
Being due to a new requirement, heater terminal covers don't need to be added to
older units.
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