Changing The Nameplate Position; Non-Return Valve; Insulation; Frost Protection - Grundfos UPED 50-12 Montage- Und Betriebsanleitung

3.3 Changing the nameplate position

When the terminal box position has been changed,
the pump nameplate must be turned so that the cut-
out points downwards. This allows water from a pos-
sible venting to escape.
To change the nameplate position, ease the outer
edge of the nameplate at the cutout with a screw-
driver, turn the nameplate to the new position and
push it into place.

3.4 Non-return valve

If a non-return valve is fitted in the pipe system, see
fig. 4, it must be ensured that the minimum discharge
pressure is always higher than the closing pressure
of the valve. This is especially important in propor-
tional-pressure control mode (reduced head at low
flows).
Fig. 4

3.5 Insulation

If the pump is insulated, it must be ensured that the
differential pressure and temperature sensor in the
pump housing is not covered.

3.6 Frost protection

If the pump is not being used during periods of frost,
the necessary steps must be taken to prevent frost
bursts.
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4. Electrical connection

The electrical connection and protection should be
carried out in accordance with local regulations.
Never make any connections in the pump
terminal box unless the electricity supply
has been switched off for at least
5 minutes.
The earth terminal of the pump must be
earthed.
The pump must be connected to an exter-
nal mains switch with a minimum contact
gap of 3 mm in all poles.
Earthing or neutralization can be used for
protection against indirect contact.
Megging must be carried out as described
in section 9. Megging.
If the pump is connected to an
electric installation where an
earth leakage circuit breaker
(ELCB) is used as an additional
protection, this circuit breaker
must trip out when earth fault
currents with DC content (pul-
sating DC) and smooth DC
earth fault currents occur.
The earth leakage circuit
breaker must be marked with
the two symbols shown.
• The pump requires no external motor protection.
• If a classification of the pump to overvoltage prop-
erty class 1 or 2 in accordance with
VDE 0160/12.90 is required, a prefilter must be
installed. Contact Grundfos for further information.
• The operating voltage and frequency are marked
on the pump nameplate. Please make sure that
the motor is suitable for the electricity supply on
which it will be used.

4.1 Supply voltage

3 x 400-415 V ±10%, 50 Hz.