Troubleshooting
Ampco Pumps Company
Page 33
Ampco Pumps Company ZP3 Manual M-004 Rev A 10.15
Troubleshooting
Each Ampco ZP3 is assembled and tested at the factory and is designed to have trouble-free
operation. Problems may occur over the life of the pump due to system variations, standard
wear, or user error. The following table has information that may help identify and solve a
problem. For additional technical assistance, please contact Ampco with the pump’s serial
number.
Symptom
Cause
Solution
NO FLOW
(rotors are not turning)
Drive motor is not running or
connected
Check connection and power source to pump
motor drive
Keys (gear, drive shaft) are
sheared or missing
Check or replace
The pump’s drive (gearbox, belts,
transmission) is broken or slipping
Check, replace, or adjust
Pump shafts or gears are broken
Check and replace, if necessary
NO FLOW
(rotors are turning)
Rotors are turning in the wrong
direction
Check motor connections for correct hookup
(see “Pump Rotation” on page 11)
Discharge port/valve is closed or
blocked
Check and open, if necessary
Inlet port/valve is closed or
blocked
Check and open, if necessary
Pump relief valve (optional) is not
set correctly, or is held open by
foreign matter.
Check and clean, if necessary. Check
system so that unwanted debris doesn’t enter
pump
NO FLOW
(pump is not priming)
Inlet valve closed
Open valve, if necessary
Inlet line restricted or clogged
Clean lines and check system
Too much air in the inlet line
Check lines for leaks, replace gaskets or
pipes, if needed
The pump’s speed is too low
Increase speed of pump
The pump’s speed is too high
Check viscosity of product, and reduce speed
as needed
No product in the inlet lines (lines
drain or siphon when pump is off)
Foot valves or check valves may be used.
Having product in the line is necessary for the
pump to prime
Pump is air locked
Install air bleeds to the pump and lines
Pump may be worn out
Increase the pumps speed or replace worn
out rotors.
Inlet pressures too low
Check pressure required. Change, if
necessary
Differential pressure differences
not developing
Install check valves on discharge to prevent
large back pressures