Grundfos CU 301 Instrucciones De Instalación Y Funcionamiento página 7

Operating relay
RELAY, terminals 8 and 9:
Terminals 8 and 9 (RELAY) are used for the
connection of an external signal transmitter (sound or
light).
The operating relay is a normally open (NO) contact
when the pump is not running, and closes while the
pump is running.
• Maximum current: 0.5 A.
• Maximum voltage: 230 VAC.
PUMP
POWER
PE
PE
Electrical connection of the operating relay
2.3 Positioning the pressure sensor
Pressure losses often cause inconvenience to the
user. CU 301 keeps the pressure constant in the
place where the pressure sensor is positioned.
relpol
RM85-3021-25-102 4
DC 24 V
AC 250 V 1 6 A
8 5
7 4
1 2
MADE IN POLAN D
4080
Pressure sensor position
Pos.
relpol
1
RM85-3021-25-102 4
DC 24 V
AC 250 V 1 6 A
8 5
2
7 4
1 2
3
MADE IN POLAN D
4080
In fig.
to the pressure sensor. Therefore, the pressure is
kept nearly constant at tap 1, as the friction loss is
small. At the shower and tap 2, the friction loss is
bigger. This, of course, depends on the pipes.
However, old and furred-up pipes may cause
inconvenience due to friction loss.
Example: A person is in the shower. Tap 2 is opened.
The increased flow causes pressure loss in the pipe,
and even though CU 301 is keeping the pressure
constant at the pressure sensor, the person in the
shower feels the pressure loss.
If the pressure sensor is placed closer to the shower
tap, CU 301 increases the pressure when the flow
rate is increased. Then the pressure at the shower
and tap 2 is kept constant, but the pressure at tap 1 is
increased.
We recommend that the pressure sensor is
positioned as close to the places of consumption as
possible.
Related information
7.1 Fault finding with Grundfos GO Remote
CU 301
3
Description
Tap 1
Tap 2
Pressure sensor
Pressure sensor position, tap 1 is placed close
1 2
7