Xylem Lowara ResiBoost MMA Series, Installation, Operation And Maintenance Manual, Page: 39 / 244

• Check the working order of the level sensor
(float, minimum pressure switch, optional probe
module panel).
• Check for the presence (level) of water on the in-
take side.
• Check the water pressure on the intake side.
N° Text on
the dis-
play (*)
Model Descrip-
tion
Reset
A2 OVER
CURR
MMW
MTW
MMA
MTA Overcur-
rent on
the mo-
tor side
of the
electric
pump.
Automat-
ic. A max
of 4 at-
tempts to
start are
made at
2 second
intervals.
Perma-
nent
locking
of the
electric
pump if
the alarm
contin-
ues to be
active af-
ter these
attempts.
Troubleshooting: The converter supplies current to
the electric motor above the set rated value. The
converter protects the motor against current over-
load.
Solutions:
• Check the condition of the windings of the elec-
tric motor.
• Check the power consumption of the electric mo-
tor.
• Check the cross-section of the motor's power ca-
ble: this must be suited to the length of the cable
and to the power of the motor.
• Check configuration of the rated current parame-
ter.
• The value of the converter's rated current must
be at least equal to the current value on the data
plate. If the power cable for the motor is longer
than 30 meters, it is advisable to increase the
value by a minimum of 10%.
• para. A models MMW and MTW. See BASIC
MENU (MB) parameters .
• para. NOM.CURR for models MMA and MTA.
See BASIC MENU (MB) parameters .
WARNING:
If the value is not configured correctly,
the motor might NOT be protected
against overload and could suffer irrepar-
able damage.
N° Text on
the dis-
play (*)
Model Descrip-
tion
Reset
A3 MOTOR
DIS
MMW
MTW Electric
motor
Manual.
N° Text on
the dis-
play (*)
Model Descrip-
tion
Reset
MMA
MTA discon-
nected
An automatic function of the converter that detects
current consumption while the motor is running. The
converter cuts out the power supply to the motor and
remains locked.
Troubleshooting:
• In the case of single-phase motors, the thermal
circuit breaker (motor protector) trips automati-
cally. The circuit breaker is located in the terminal
box, a separate electrical panel or in the motor,
depending on the model of the electric pump (re-
fer to the relative manual).
• Breaking or failure of a phase of the motor.
• Failure/disconnection/deterioration of a phase of
the motor's power cable.
• Breaking of the converter's fuse, refer to Figure
13 and Figure 15 .
• For single-phase submerged motors with float.
Check the float to see if it is broken or has trip-
ped.
N° Text on
the dis-
play (*)
Model Descrip-
tion
Reset
A4 PRESS
MIN
MMW
MTW
MMA
MTA Minimum
pressure
alarm
Automat-
ic, with
reset
tests.
The pressure of the system does not exceed the set
value of the MP (MMW/MTW) or (MMA, MTA) pa-
rameter. After the delay dL (MMW, MTW) or MP DE-
LAY (MMA, MTA), the pump is stopped and protect-
ed against dry running. The ART function is activat-
ed. See Special functions .
Troubleshooting:
• No water on the intake side of the pump: check
the level or pressure of the water.
• Pump not primed. Prime the pump.
• The pipe on the delivery side of the pump is bro-
ken. The flow of water is too high.
• The pump (impeller or diffuser) is damaged. Con-
tact the technical assistance service.
• The motor is damaged and must be replaced.
N° Text on
the dis-
play (*)
Model Descrip-
tion
Reset
A5 FAULT
SENS
MMW
MTW
MMA
MTA Fault
with the
pressure
sensor
Automat-
ic
Troubleshooting: The pressure sensor is faulty.
en - Original instructions
39