Grundfos SP 11 Installation And Operating Instructions Manual Download Page 8

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English (GB)

The supply voltage, rated maximum current and cos

appear

from the separate name plate which must be fitted close to the
installation site.
The required voltage quality for MS and MMS motors, measured
at the motor terminals, is - 10 %/+ 6 % of the nominal voltage
during continuous operation (including variation in the supply
voltage and losses in cables).
Check also that there is voltage symmetry in the power supply
lines, i.e. same difference of voltage between the individual
phases. See section , item 2.
If MS motors with a built-in temperature transmitter (Tempcon)
are not installed together with an MP 204 motor protection unit,
they must be connected to a 0.47

F capacitor approved for

phase-phase operation (IEC 384-14) to meet the EC EMC
directive (2004/108/EC). The capacitor must be connected to the
two phases to which the temperature transmitter is connected.
See fig.

Fig. 7

Connection of capacitor

The motors are wound for direct-on-line starting or star-delta
starting, and the starting current is between four and six times the
rated current of the motor.
The run-up time of the pump is only about 0.1 second.
Direct-on-line starting is therefore normally approved by the
power supply company.

6.1 Motor protection

6.1.1 Single-phase motors

Single-phase MS402 motors incorporate a thermal switch and
require no additional motor protection

As an exception, the 1.1

kW (1.5 hp) MS402 requires external current protection

Single-phase MS4000 motors must be protected. A protective
device can either be incorporated in a control box or be separate.

6.1.2 Three-phase motors

MS motors are available with or without a built-in temperature
transmitter.
Motors with a built-in and operational temperature transmitter
must be protected by:
• a motor-protective circuit breaker with thermal relay or
• an MP 204 motor protection unit and contactor(s).
Motors with or without a non-operational temperature transmitter
must be protected by:
• a motor-protective circuit breaker with thermal relay or
• an MP 204 motor protection unit and contactor(s).
MMS motors have no built-in temperature transmitter. A Pt100
sensor is available as an accessory.
Motors with a Pt100 sensor must be protected by the following:
• a motor-protective circuit breaker with thermal relay or
• an MP 204 motor protection unit and contactor(s).
Motors without a Pt100 sensor must be protected by the
following:
• a motor-protective circuit breaker with thermal relay with max.

trip class 10 according to IEC 60947-4-1 or

• an MP 204 motor protection unit and contactor(s).

6.1.3 Required settings of motor-protective circuit breaker

For motors with an MP 204 motor protection unit, Grundfos
recommends using a special trip curve with P-characteristics at a
setting of Un times 5 for 1 second.
For cold motors, the tripping time for the motor-protective circuit
breaker must be less than 10 seconds at five times the rated
maximum current of the motor.
For all Grundfos submersible MMS motors, the maximum start
and stop ramp time is 3 seconds (minimum 30 Hz).

In order to ensure optimum protection of the submersible motor,
set th motor-protective circuit breaker in accordance with the
following:
1. Set the motor-protective circuit breaker to the rated maximum

current of the motor.

2. Start the pump and let it run for half an hour at normal

performance.

3. Slowly grade down the scale indicator until the motor trip point

is reached.

4. Increase the setting by 5 %.

Colours of the conductors

Conductor

Flat cable

Single conductors

1 = L1

Brown