Direction Of Rotation; Maintenance And Service - Grundfos DP 10 Serie Montage- Und Betriebsanleitung

9.3 Direction of rotation

The pump may be started for a very short
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period without being submerged to check
the direction of rotation.
All single-phase pumps are factory-wired for the
correct direction of rotation.
Before starting up three-phase pumps, check the
direction of rotation.
An arrow on the stator housing indicates the correct
direction of rotation.
The impeller rotates clockwise when the
pump is viewed from above. When started,
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the pump will jerk in the opposite direction
of the direction of rotation.
If the direction of rotation is wrong, interchange any
two of the phases in the power supply cable.
See fig. 6 or 7.
Checking the direction of rotation
Check the direction of rotation in one of the following
ways every time the pump is connected to a new
installation.
Procedure 1:
1. Start the pump and check the flow of liquid or the
outlet pressure.
2. Stop the pump and interchange any two of the
phases in the power supply cable.
3. Restart the pump and check the quantity of liquid
or the outlet pressure.
4. Stop the pump.
5. Compare the results taken under points 1 and 3.
The connection which gives the larger quantity of
liquid or the higher pressure is the correct
direction of rotation.
Procedure 2:
1. Let the pump hang from a lifting device, e.g. the
hoist used for lowering the pump into the pit.
2. Start and stop the pump while observing the
movement (jerk) of the pump.
3. If connected correctly, the pump will jerk in the
opposite direction of the direction of rotation. See
fig. 12.
4. If the direction of rotation is wrong, interchange
any two of the phases in the power supply cable.
See fig. 6 or 7.
Fig. 12 Jerk direction

10. Maintenance and service

Warning
Before starting work on the pump, make
sure that the fuses have been removed or
the mains switch has been switched off.
Make sure that the power supply cannot
be accidentally switched on.
All rotating parts must have stopped
moving.
Warning
Except for service on the pump parts, all
other service work must be carried out by
Grundfos or a service workshop
authorized by Grundfos and approved for
servicing explosion-proof products.
Before carrying out maintenance and service, make
sure that the pump has been thoroughly flushed with
clean water. Rinse the pump parts in water after
dismantling.
Warning
When loosening the screws of the oil
chamber, note that pressure may have
built up in the chamber. Do not remove the
screws until the pressure has been fully
relieved.
If the pump is inactive for long periods of
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time, we recommend that you check the
function of the pump.
Service videos can be found in Grundfos
Note
Product Center at www.grundfos.com.
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