Insulation Resistance; Emergency Operation (Only 11-22 Kw) - Grundfos CRE Montage- Und Betriebsanleitung

17. Insulation resistance

0.37 - 7.5 kW
Do not measure the insulation resistance of motor
Caution
windings or an installation incorporating E-pumps
using high voltage megging equipment, as this may
damage the built-in electronics.
11-22 kW
Do not measure the insulation resistance of an
installation incorporating E-pumps using high voltage
megging equipment, as this may damage the built-in
Caution
electronics.
The motor conductors can be disconnected
separately and the insulation resistance of the motor
windings can be tested.

18. Emergency operation (only 11-22 kW)

Warning
Never make any connections in the pump terminal
box unless all electric supply circuits have been
switched off for at least 5 minutes.
Note for instance that the signal relay may be
connected to an external supply which is still
connected when the mains supply is disconnected.
If the pump is stopped and you cannot start the pump
immediately after normal remedies, the reason could be a faulty
frequency converter. If this is the case it is possible to maintain
emergency operation of the pump.
Before change over to emergency operation we recommend you
to:
• Check that the mains supply is OK.
• Check that control signals are working (start/stop signals).
• Check that all alarms are reset.
• Make a resistance test on the motor windings (disconnect the
motor conductors from the terminal box).
If the pump remains stopped it is possible that the frequency
converter is faulty.
To establish emergency operation proceed as follows:
1. Disconnect the three mains conductors, L1, L2, L3, from the
terminal box, but leave the protective earth conductor(s) in
position on the PE terminal(s).
2. Disconnect the motor supply conductors, U/W1, V/U1, W/V1,
from the terminal box.
3. Connect the conductors as shown in fig. 34.
Fig. 34 How to switch an E-pump from normal operation to
emergency operation
Use the screws from the mains terminals and the nuts from the
motor terminals.
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