EBARA HERTZ ONE Manual página 28

9.2 OPERATIONAL CONTROL.
1) Once the settings have been made in table 9.1.1, press button
2) With the delivery valve open at a quarter of the unit's maximum delivery, press button
automatically light.
3) If the system pressure is lower than the PSET - Pr, the pump that is not supplied by the inverter starts to rotate and the green LED
lights. The pressure should gradually increase to the set pressure otherwise, the inverter should reduce the motor speed in order to
maintain the set pressure.
START
4) Press button of pumps two and three (where expected), the related yellow LEDs should light but the pumps shouldn't start.
MANUAL
5) Gradually open the delivery valve, the frequency of motor one should reach 50 Hz, and after two seconds the second electric pump
should start to restore the pressure of the system and the speed of the first pump should lower so as not to cause overpressure.
6) Fully open the delivery valve, the frequency of motor one should reach 50 Hz, and after two seconds the third electric pump should start
to restore the pressure of the system and the speed of the first pump should lower so as not to cause overpressure.
7) With the maximum delivery, gradually close the valve, the pressure should remain within the factory limits ± 0.2 bar in relation to the
PSET parameter and when the frequency of pump one drops below the VEL parameter, the pumps in cascade should stop one after the
other.
8) When they stop the first inverter supplied pump should compensate the pressure of the system if necessary by increasing its speed.
CP < 50 slow inverter reaction
CP > 50 fast inverter reaction
N.B.: Usually no need to alter this parameter.
9) When pump one is running only, gradually and totally close the valve and wait for the pumps to automatically stop. All green LEDs
should switch off, and the yellow LEDs should remain on, signalling that the pumps are ready to start.
10) The next time all three electric pumps start, pump one starts supplied by the inverter while the other two interchange the starting order.
11) Possible alarms that are signalled by the red LED
12) In systems with two and/or three and/or four HERTZ ONE, check the cascade starting of the second HERTZ ONE making sure that the
first has reached the speed of 50 Hz and that two seconds have lapsed.
A reduction in the frequency of the two HERTZ ONE should be noted if the request of water does not increase.
If the request of water increases, both HERTZ ONE will increase their frequency up to 50 Hz.
Close the delivery valve and both HERTZ ONE should reduce their frequency to a value lower than the set VEL value and one of the two
HERTZ ONE should cut out after two seconds.
If the valve remains partially open the HERTZ ONE that is still running will temporarily increase its speed, otherwise it will reduce its
speed and finally stop.
The next time that the delivery valve is opened, check the starting order of the HERTZ ONE.
ENGLISH
until the instantaneous pressure parameter P 00,0 appears.
!
must be checked in table 9.3.
27
P1
START
, the yellow signal
MANUAL
should
P1