Bosch SHE55P Repair Manual page 15

4.1.6.3 Cavitating
Cavitating may occur in any type of pump when impellers spin
faster (from low inlet or outlet pressure), creating air pockets
around impellers. Cavitating pumps can be noisy. Air gaps/high
loops keep water contacting pump outlets, preventing air pockets
from forming.
4.1.6.4 Siphoning
Siphoning may occur in any type of drain pump when low water
flow allows a siphon (suction) to develop, pulling waste water
back into the pump. Sump check valves along with air gaps/high
loops prevent siphons from being created.
4.1.6.5 Terminal connections
Drain pump terminals were changed from spade type to (Rast 5)
connectors during November, 2006 and can't be interchanged.
702_58300000148618_ara_en_a
4.1.6.5.1 Spade terminals (UC/42 and before)
Wire harnesses to drain pumps have locking spade terminals,
which must be released using a small blade screwdriver.
4.1.6.5.2 Rast 5 connectors (UC/43 and later)
Rast 5 terminal connectors provide more positive connections
than spade terminals.
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