Product Manual

SQ, SQE applications
SQ, SQE, CU 331, and SP
2
9
Constant-pressure control with CU 301,
irrigation
The system maintains a constant pressure within the
maximum pump performance in spite of a varying
water consumption.
The pressure is registered by means of the pressure
sensor and transmitted to the CU 301. The CU 301
adjusts the pump performance accordingly.
Function
When the sprinkler system is started, the pressure in
the tank will start to drop.
At a flow lower than approximately 1 gpm (0.18 m
3
/h),
the pressure will drop slowly. When the pressure in the
tank is 7 psi (0.5 bar) below setpoint, the pump will
start. The pump will run until the pressure is 7 psi
(0.5 bar) above setpoint. This way of operation is
called on/off operation.
At a flow higher than approximately 1 gpm (0.18 m
3
/h),
the pressure will drop quickly and the pump will start
immediately and maintain a constant pressure.
During operation, the CU 301 will regulate the pump
speed to maintain a constant pressure. If there is no
consumption, the pump will boost the pressure to 7 psi
(0.5 bar) above setpoint and stop after a few seconds.
Fig. 7 Application example: Constant-pressure control with CU 301 - irrigation
TM03 3428 2810
Min. 20 inches (0.5 m)
Recommended min. 20 inches
(0.5 m)
1 Pump, SQE
2 Cable
3 Cable clips
4 Pressure tank 2 gal (8 liter)
5 Control unit, CU 301
10 Pressure sensor, 0 - 120 psi (0-6 bar)
14 Pressure gauge
18 Sprinkler system
21 Mains connection
22 Riser pipe
30 Safety cable
31 Wire clamp
Pos. Part Type No. of units Product number Unit price Total price
1Pump SQE
2 Cable
3 Cable clips
4 Pressure tank 2 gal (8 liter)
5 Control unit CU 301
10 Pressure sensor 0-120 psi (0-6 bar)
14 Pressure gauge
30 Safety cable
31 Wire clamp