Pentair Pool Products Myers MWH50 Series Installation And Service Manual page 8

To find if rotation is correct operate pumps and check
delivery operation. If flow and head is low (refer to
pump curves shown in this manual) the rotation is
wrong. With duplex pumps, check operation of both
pumps.
(5) All pump impellers, either single or three phase, must
turn counterclockwise when looking into pump inlet.
If uncertain of rotation, TURN OFF POWER and lift
pump from basin with cord connected and lay pump
on side so impeller can be seen. Turn on power and
start pump using hand position of H-O-A switch.
Turn on and off fast so that coast of impeller can be
seen. NEVER PUT HAND OR FINGERS ON THE
IMPELLER. Interchange any two l line leads at the
magnetic starter to change rotation.
POINTS TO CHECK IF PUMP DOES NOT RUN
OR DOES NOT RUN PROPERLY
(1) Pump does not run or start when water is up in tank.
(a) Check for blown fuse or tripper circuit breaker.
(b) Check for defective level switch.
(c) Where control panel is used be sure H-O-A switch
is in the AUTO position. If it does not run, turn switch
to the HAND position and if the pump runs then the
trouble is in the automatic electrical system. Have an
ELECTRICIAN make electrical checks.
(d) Check for burned out motor. Occasionally lightning
can damage a motor even with lightning protection.
(e) Where plug-in cords are used be sure contact
blades are clean and making good contact. DO
NOT USE PLUG-IN CORDS INSIDE A SUMP OR
WET WELL.
(f) Level control ball or weight may be stuck on side
of basin. Be sure it floats freely.
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(2) Pump runs but does not deliver flow.
(a) Check air lock. Start and stop pump several times;
if this does not help it may be necessary to loosen
a union in the discharge line to relieve air lock.
(b) Check valve may be installed backwards. Check
flow arrow on valve body. Check shut-off valve. It
may be closed.
(c) Check vertical elevation. It may be higher than
pump can develop. (See pump curve).
(d) Pump inlet may be plugged. Remove pump to
check.
CAUTION: ALWAYS UNPLUG POWER CORDS OR
TURN OFF ALL MAIN AND BRANCH CIRCUIT BREAKERS
BEFORE DOING ANY WORK ON THE PUMP. If control
panel is remote from pump, disconnect lead wires to
motor so that no one can turn the circuit breaker back
on. If motor is three phase, mark the leads so they can
be replaced in the same order.
BEFORE DISMANTLING PUMP FOR
REPLACEMENT OF PARTS
Clean pump thoroughly. Knock off all scale and deposits.
Use sandblast if possible. Submerge complete unit in
Clorox solution for one hour before taking apart.
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