TROUBLESHOOTING
SYMPTOMS
Pump runs, but no water delivered
Not enough water delivered
Not enough pressure
Excessive vibration
Abnormal Noise
Pump stops
Overheating
CAUSE
ELECTRICAL
A . No voltage in power system .
B . No voltage on one phase (Three Phase units) .
C . Low voltage at motor .
D . Motor leads improperly grouped for voltage .
E . Control failure .
F . Thermal overload switch open
G . Installation failure .
H . Open windings .
I . Frequency variation .
MECHANICAL
A . Flow through pump completely or partially
obstructed .
B . Wrong direction of rotation .
C . Pump lost prime .
D . Internal leakage .
E . Loose parts
F. Stuffing box not properly adjusted
SYSTEM
A. Pressure required by system at design flow rate
exceeds pressure rating of pump .
B . Obstruction in suction piping
C . Pressure rating of pump exceeds pressure
requirement of system at design flow rate.
P15008 (04-15-2023)
ELECTRICAL
A
B
C
D
E
F
X
X
X
X
X
X
X
X
X
X
X
X
X
Check phase-to-phase on line side of starter contactor .
Check phase voltage on line side of starter contactor . Isolate open circuit
Running voltage across each leg of motor must be ±10% of nominal voltage
Refer to lead grouping diagram on motor nameplate .
Check control device, starter contactor, H-O-A selector switch, etc ., for malfunction .
Check phase-to-phase on line side of starter contactor .
Check motor or windings to ground with megohmmeter .
Check frequency of power system . Must be less than 5% variation from
Locate and remove obstruction . Refer to repair instructions for disassembly .
Reverse rotation of three phase motor by interchanging any two leads . See manufacturer's
Check impeller for wear of controlled clearances (See Repair Instructions) .
Compare pump pressure and flow rate against pump characteristic curve. Check for
closed or partially closed valve in discharge piping system .
Reduce system pressure requirement . Increase pressure capability of pump .
Compare pump pressure and flow rate against pump characteristic curve.
Inspect discharge piping system for breaks, leaks, open by-pass valves, etc .
If necessary, reduceflow rate by partially closing discharge valve.
PROBABLE CAUSE
MECHANICAL
G
H
I
A
B
X
X
X
X
X
CORRECTIVE ACTION
Check circuit breaker or fuses
(circuit breaker, fuse, broken connections, etc .)
shown on nameplate .
Check leg-to-leg with ohmmeter .
motor nameplate rating .
instructions for reversing single phase motor .
Reprime . Inspect suction system for air leaks .
Inspect . Repair .
Adjust gland.
Locate and remove obstruction .
SYSTEM
C
D
E
F
A
B
X
X
X
X
X
X
X
X
X
X
X
X
C
X
X
X
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