Trouble-Shooting Chart - Nastec 4HS Installation And Operating Manual

12. Trouble-shooting chart

LCD does not switch on
after powering the CM
Power line of CM is
interrupted by the
differential protecting
contactor
When performing the
Offset operation of the
pressure device, SENS.
PRESS. OFF alarm
occurs
Frequency and
pressure oscillation on
constant pressure
control mode
During constant
pressure control, pump
stops and starts
continuously..
Measured pressure
p_m drops too much
before 4HS turning on
the pump.
30

Check the connecting flat cable between the LCD board (fixed to the
cover) and the control board.

Check the fuses.

Check the feeding cable are properly connected (L1, L2, ground).

Check the leakage current to ground of EMC filter.

following a rapid off/on operation the power supply differential
contactor can interrupt again the power . After turning off the 4HS is
therefore recommended to wait at least 1 minute before start the
system.

check that the sensor cable is properly connected to the sensor device
and CM.

Make sure that the sensor and its cable are no damaged.

Check that the range of pressure sensor is of 4 -20 mA type and the
value of 15 V will be within its voltage feeding range.

Check if the water tank and its air pressure are correct. In addition, it is
suggested to increase the tank volume or reduce the pre-charge
pressure.

Check the ki e kp parameters (Installer Parameters menu).
At first, it is advisable to increase the Ki value. If it not enough, reduce
of one unit the Kp value.

Make sure that the value f min Q=0 (minimum frequency with Q=0)
(Installer Parameters menu) is properly set up. Otherwise repeat the
procedure.

Increase the value of parameter stop delay Q=0 (Installer Parameter
menu).

Increase the value of "Ramp Q=0" parameter (Installer Parameters
menu).

Decrease the delta start pressure (Installer Parameters menu).

Decrease the delta start pressure (Installer Parameters menu).

Check if the water tank and its air pressure are correct. In addition it is
suggested to increase the tank volume or reduce the pre-charge
pressure.

Modify the value of ki e kp parameters (Installer Parameters menu).
At first, it is advisable to reduce the Ki value. If it is not enough,
increase of one unit the Kp value.