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Model CDMD
I&O IN-159
performance, voiding
warranty. It is best to check
rotation by
momentarily
energizing motor prior to
filling pump with liquid.
Warning! Do not
operate pump without
liquid for more than a
moment, as damage will
result to the pump
internal wear surfaces.
PLUMBING
All piping should be supported
independently of the pump.
Piping should not exert any
stress on the pump
connections.
1. Suction Piping-Horizontal
Pumps.
Suction line must
provide adequate suction
pressure and smooth liquid
flow for proper pump
operation. Air entrapment in
the suction line because of
leaks or improper design may
cause the pump to lose prime
and fail. The CD Mag Drive
series pump is not self-
priming, therefore the suction
must be flooded and the pump
entirely filled with liquid at
start up. Also, the suction line
must provide sufficient
pressure and smooth flow to
pump inlet to prevent pump
cavitation. A length of straight
pipe a minimum of 5 times the
pump inlet diameter and
preferably 10 times the
diameter should be installed in
the suction line where it enters
the pump. Elbows, fittings or
valves installed close to the
suction can disrupt liquid flow
and cause malfunction and
damage. Suction lines must be
at least the same size as the
pump inlet or larger if
possible. Price Pump
Company recommends against
using foot valves in the suction
line to maintain liquid in the
pump when it’s not operating.
If foot valves are used due to
suction lift conditions they
must be properly maintained to
avoid leaks resulting from
wear or fouling.
2. Discharge Piping.
For
flow and discharge head
control it is advisable to install
a valve (globe, ball, or other
adjustable and non-leak type)
in the discharge line close to
the pump. The valve may be
closed during system repairs to
prevent backflow. By
installing a check valve in the
discharge line backflow can
also be prevented during
maintenance or during periods
of pump stoppage.
OPERATION
Priming
. All centrifugal
pumps must be filled with
liquid prior to start up. For the
CDMD series pump illustrated
in this manual completely fill
the volute and suction lines
prior to operation. It is
suggested that during initial
start up the discharge valve be
closed and then opened as the
motor develops full rpm’s. If
pump does not build up
pressure as motor speed
increases, shut down and
reprime pump, plus make sure
that liquid flow into pump is
not restricted (see
“Troubleshooting”).
Note: A centrifugal pump’s
flow and head (pressure) will
vary with the amount of
resistance (friction and flow
restrictions) in the discharge
line. As a valve on the
discharge line opens the flow
and motor amperage will
increase and head will drop.
As a valve on the discharge is
closed the flow and amp draw
will decrease and the head will
increase. If resistance in the
discharge line is not sufficient
the pump will operate at a
condition of maximum flow,
also sometimes called “end of
performance curve.”
Maximum horsepower is
required to operate at this
point and motor overload may
result. If excessive amperage
draw and motor overload is
recurring, reduce the system
flow by installing a valve on
the discharge line and
restricting flow. Alternatively,
reduce pump head by trimming
impeller to a smaller diameter.
Consult local Price Pump
dealer for assistance.
CAUTION
Disconnect power to pump
before servicing to avoid
dangerous or fatal electrical
shock hazards.
If pump has been used to
pump hazardous materials
be certain that all materials
