9.4 Frequent starts and stops
Cause
Remedy
The difference between
start and stop level is too
small.
Increase the differential.
Level sensor is activated.
Lower the pump deeper
into the borehole, throttle
the pump or replace it
with a smaller model to
obtain a lower perform-
ance.
The non-return valve is
leaking or stuck half-
open.
Remove the pump from
the borehole and clean
or replace the non-return
valve, if necessary.
The supply voltage is un-
stable.
Ensure sufficient power
from the power source.
Check the specified volt-
age output from the pow-
er source.
Low power supply.
Ensure sufficient power
from the power source.
The motor temperature is
too high.
Check the water temper-
ature and secure suffi-
cient flow around the mo-
tor. If necessary, remove
the pump from the bore-
hole and add a flow
sleeve for cooling.
9.5 How to check the power supply
DANGER
Electric shock
Death or serious personal injury
‐
Switch off the power supply before you
start any work on the product.
1. See the Grundfos service instruction by scanning
the QR code.
TM070145
http://net.grundfos.com/qr/i/96547278
2. Follow the instructions for the relevant
system issued in the Grundfos service instruction.
9.6 Megging
Do not meg an installation incorporating
this product as the built-in electronics may
be damaged.
L
N
PE
U
U
U
C
C
C
TM071582
10. Technical data
10.1 Operating conditions
Liquid temperature
Maximum 40 ºC
pH value
5-9
10.2 Mechanical data
Storage tem-
perature
-20 to +60 ºC
Motor liquid
Type SML 3, frost-proof down to -20
ºC
Motor cable
2 m, 3 x 1.5 mm
2
Pump outlet
size
RP 1 and Rp 1 1/4
18
English (GB)
