Pump Placement - Honda WH15XT Manuel De L'utilisateur

OPERATION

PUMP PLACEMENT

For best pump performance, place the pump near the water level, and
use hoses that are no longer than necessary. That will enable the pump
to produce the greatest output with the least self-priming time.
As head (pumping height) increases, pump output decreases. The
length, type, and size of the suction and discharge hoses can also
significantly affect pump output.
Discharge head capability is always greater than suction head
capability, so it is important for suction head to be the shorter part of
total head. The maximum available suction head will vary based on the
operating conditions. However, the suction head can never exceed 
8 meters (26 feet) and should always be kept as low as possible.
Minimizing suction head (placing the pump near the water level) is also
very important for reducing self-priming time. Self-priming time is the
time it takes the pump to bring water the distance of the suction head
during initial operation.
DISCHARGE
HEAD
SUCTION HEAD
LESS THAN 
8 METERS
(26 FEET)
20
TOTAL HEAD