BOOSTER PUMP SYSTEM
59
BOOSTER PUMP SYSTEM N747D
Set starting deviation pressure value becomes the condition of pump
starting when operation mode is switched to emergent automatic
operation. Setting of starting deviation pressure is available, however
its initial value is set as 0.5bar.
In this case, if set pressure is 4.0 bar, then sequential auxiliary pump
starts if it’s not above 3.5bar.
As the condition to stop is depend on the set value of auxiliary stop
deviation pressure, if auxiliary stop deviation value is 0.5bar, then it
shall be 4.5bar to stop the pump sequentially.
In this process, after all pumps stop and then if it’s 3.5bar or less
then it operates again.
The stating deviation pressure can be corrected through sequential
operation pressure and sequential stop pressure items of “User
setting [1]”. Please note that if the value is too small, the frequency of
starting/stop increases. Please call our A/S team to get support while
the pump operates under emergent automatic operation mode.
Indications :
In case of inverter failure, auto emergent operation is carried out
automatically and the failure notice is indicated in main screen. In the
bottom of present pressure of initial screen, the notice of “Inverter is
abnormal” is indicated, so please make sure to check it in daily
check.
2. sequential 1 operation
Reason :
When replacing of abnormal inverter
Starting method :
Starting method is same as the principle of automatic emergent
operation in case of inverter failure. In “sequential 1 operation”,
emergent operation is carried out forcibly as because water can be
supplied only by pump when inverter shall be replaced due to
inverter failure. sequential 1 operation can be carried out through
“Installer’s setting”. “Installer’s setting” is only for authorized
engineers, but not disclosed to general consumers due to the
possibilities including serious failure or accident by unauthorized
change of settings.
Caution : User’s setting mode shall be accessed only by authorized
engineers.
3. sequential 2 operation
Reason :
In case inverter and pressure transmitter failed at the
same time.
Starting method: