Settings; Startup - Lowara GHV Serie Montage- Und Betriebsanleitung

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5. Settings

Disconnect the power supply before making any adjustments.
For the settings, refer to the converter operating instructions
Operation
The starting and stopping of the pumps are determined based on the pressure settings of the controller.
Each frequency converter is connected to a pressure transmitter. The converters share all the information
and provide for cyclic changeover.
The figure shows the operating method with the curves for two pumps
- The tank supplies water upon demand by a user.
- When the pressure drops below the PS value, the first
pump is started and the speed is adjusted to maintain a
constant pressure as the demand increases
- If the demand keeps increasing and the pump reaches
maximum speed, the second pump is started and the
speed is adjusted to maintain a constant pressure.
- When the demand decreases the speed is reduced until
minimum speed is reached; at this point one of the pumps
is deactivated.
- If the demand decreases further the pump slows down, fills
the tank and then stops when the PS value is reached
Converter Adjustments
If you need to modify the settings, refer to the converter operating instructions. Use the converter keypa-
nel to set a new pressure adjustment value, select the language, view the latest alarms or access all the
adjustment settings.
Tank Precharge
To ensure its proper operation, the membrane tank must be precharged to 0.9 x adjustment pressure
value. The precharge operation must be performed with the tank empty.

6. Startup

To start the set, proceed as follows:
a) Connect the water supply
b) Connect the power supply
c) Check the tank precharge value
d) Close the pump delivery valves
e) Prime the set ( see pump instructions manual) and suction manifold
f) Operate the switch on the panel to supply power and set the converter to manual mode operation.
g) Start the first pump
h) Slowly open the pump delivery valve and bleed the air
i) Repeat the above operations for the other pumps
j) Set the converters to automatic mode operation.
How to Modify the Settings
After the set has been started, proceed as follows to modify the settings within the maximum pressure li-
mits of the pumps and/or system:
a) Determine the required pressure value
14
H
Pmax
PS
Fig 3
Q