Electrical Connection; Frost Protection; Fault Finding - Grundfos CR Instrucciones De Instalación Y Funcionamiento

3.2 Ejector connection
1. Connect the larger pipe dimension (1¼") to the diffusor (the
long ejector pipe) and to the priming container.
2. Connect the smaller pipe dimension (1") to the nipple (the
short ejector pipe) and to the outlet on top of the pump.
3.2.1 Ejectors with iron pipe connection
Ejectors with iron pipe connection have Whitworth thread and are
connected as usual.
Fit a pipe clamp 3 to 4 metres above the ejector to keep the pipes
at the right distance to each other, thus preventing damage to the
ejector.
3.2.2 Ejectors with plastic tube connection
Ejectors with plastic tube connection (PE) have unions and are to
be connected as follows:
1. Cut the pipe at right angles.
2. Chamfer the inside and outside of the pipe.
3. Heat the pipe end to be connected to the ejector in boiling
water to soften it.
4. Press the pipe home on the knurled taper of the ejector (A).
5. Slide the external ejector taper (B) up around the plastic tube.
6. Tighten the ejector nut (C) until the pipe is securely fixed.
A
1"
B
C
Fig. 3 Ejector with plastic tube connection
3.3 Fitting the discharge pipe
Fit an isolating valve in the discharge pipe between the pump and
pressure tank for use at start-up.
It is not advisable to use a non-return valve between the pump
and pressure tank.
The pipe dimension between the pump and the pressure tank
must correspond to the discharge connection of the pump. For
further information on connection dimensions, see the installation
and operating instructions of CR, CRI, CRN.
3.4 Installing the pressure tank and pressure switch
Install the pressure tank and pressure switch as described in the
installation and operating instructions of the products.
3.4.1 Precharge pressure of pressure tank
Unless otherwise stated, the precharge pressure of the pressure
tank can be calculated as follows:
Precharge pressure = 0.7 x cut-in pressure.
3.4.2 Cut-in pressure
The cut-in pressure is set on the pressure switch by means of two
setting screws for cut-out pressure and differential pressure,
respectively.
Cut-out pressure The pump stops.
Differential pressure Pressure drop. The pump starts again.
Cut-in pressure = cut-out pressure – differential pressure.
Example
Cut-out pressure 5 bar
Differential pressure 1.5 bar
Cut-in pressure 3.5 bar
1 ¼"
B
C

4. Electrical connection

The electrical installation of the pump must be carried out as
described in the installation and operating instructions of CR,
CRI, CRN.
5. Start-up
1. Close the isolating valve between the pump and the pressure
tank.
2. Remove the air vent screw of the pump.
3. Remove the plug of the priming container and fill the container
with clean water until the riser riser pipe and the container
have been filled.
4. Start the pump. The priming container is now being emptied.
Keep filling the container with water until all air has been
removed from the system and an air-free water flow comes out
of the priming container.
5. Fit the air vent screw.
6. Slowly open the isolating valve between the pump and the
pressure tank until just a little water flows out of the priming
container.
7. Fit the plug into the priming container while the pump is run-
ning, and tighten the plug.
8. Slowly open the isolating valve between the pump and the
pressure tank until it is completely open.
6. Maintenance
The pump system requires no maintenance if it is installed
according to the instructions.

7. Frost protection

The pump must be protected against frost as described in the
installation and operating instructions of CR, CRI, CRN.
The remaining pump system must be sufficiently protected
against frost.

8. Fault finding

8.1 Fault finding of pump
See the installation and operating instructions of CR, CRI, CRN.
8.2 Fault finding of pump system
If only a little water is pumped out of the hole for the air vent
screw during start-up, the cause may be:
• The ejector is not sufficiently submerged.
• The pump system is partly filled with air and thus not primed
sufficiently.
• The ejector nozzle is clogged.
If the start-up has been carried out as described in 5. Start-up
without any result, the ejector is most likely not sufficiently sub-
merged, or the ejector nozzle is clogged.
If the pump pressure is reduced in relation to the total pump pres-
sure, the most likely causes are:
• The ejector is not sufficiently submerged.
• The pump system is partly filled with air and thus not primed
sufficiently.
• The pump runs with wrong direction of rotation.
5