Lowara GEMK Serie Instrucciones Para La Instalación Y El Uso página 94

Figure 1.1 shows the operating method for sets with two pumps:
- When the pressure drops to the P1 value the first pump starts.
- If the pressure drops to the P2 value the second pump starts.
The pumps may only be stopped manually by pressing a STOP button, with the
exception of the version for fire-hydrant networks, where the pump shuts off
automatically after the pressure has been restored for a length of time (P1s).
Pressure switch
The pressure switches are set at the factory using a set of values that depend on the type
of pump and the provisions of standard EN12845. The calibration values are indicated on
a plate either on the module or in the panel, or in the documentation.
In order to modify the settings according to the system's hydraulic conditions (figure 1.2):
- With Pump off and pressure to zero, the central screw (1) has to be screwed to reach
the bottom of the pressure scale.
- Turn the duty pump or jokey pump and through the valve of test circuit (flow) to get the
delivery pressure equal to the pressure of STOP desired.
- With Pump on, the central screw (1) has to unscrew until the pressure switch switches.
- Through the valve of circuit test (flow meter) lower the delivery pressure to the pressure
value of start desidered.
- With Pump on, the differential screw (2) has to unscrew until it snaps back the
pressure.
Warning: each pump has two pressure switches connected; these must have the same settings. The pump starts when
the first one is triggered.
5.3 Commissioning and checking operation of the jockey pump
The jockey pump, provided on board the electric service pump (GEM..J) or as a kit, is an auxiliary pump for small amounts of
water and is recommended to avoid starting up the main pumps unnecessarily. The choice of jockey pump should be able to
provide sufficient water and pressure for a single sprinkler (EN 12845, 10.6.2.5).
It starts up automatically, controls a pressure switch at a pressure above the starting pressure of the main pumps, and stops
independently when the pressure of the system is restored.
Operation:
1) Connect the water supply
2) Connect the wires of the power cable to the control panel, prioritizing the ground wire.
3) Prime the pump (refer to the pump booklet) and the inlet pipes.
4) Turn the switch to its "0" position.
5) Turn the main door-lock switch QS on the electric pump panel to its "ON" position.
6) Turn the switch to its "MAN" position. The electric pump starts up.
7) Check in which direction the electric pump turns and, looking from the side of the fan, check that the motor turns
clockwise.
8) If it turns in the wrong direction, turn off the electric panel by turning the switch to its "0" position and the main door-lock
switch to its OFF position, and invert the two power phases on the terminal block of the electric motor. Turn the electric
panel on again by turning the main door-lock switch to its "ON" position.
9) Turn the switch of the panel of the electric pump to its "AUT" position.
10) Open a test valve of the system to reduce the pressure to below the starting pressure of the pressure switch.
11) Open a test valve of the system to reduce the pressure to below the starting pressure of the pressure switch.
12) Check that the jockey pump starts up automatically and in the correct manner.
13) Close the valve. Wait for the pressure to increase again above the stopping value of the pressure switch.
14) Check that the jockey pump turns up automatically and in the correct manner.
15) Turn the switch of the panel of the electric pump to its "0" position.
16) Turn the switch on the panel of the jockey pump to its "AUT" position after the main pumps have all been
commissioned.
During operation
ATTENTION
- Check the system and stop the electric pump if there are any signs of leaking.
94
H
Fig. 1.1
P1s
P2s
P1
P2
1
2
Q
Fig. 1.2