Measuring Insulation Resistance; Installation Of The Submersible Electropump - F.B. SUBMERSIBLE MOTORS 6 Manuel De Montage Et D'utilisation

5.5 Measuring insulation resistance

Information
5.6 Electrical connection of the submersible electropump
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Risk of death due to an electric shock.
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Connection diagram for three-phase motors
CONNECTION FOR DIRECT START
Power leads
Motor leads
CONNECTION FOR STAR
Connect together and
insulate with connection
Power leads
Motor leads
U2 V2 W2

5.7 Installation of the submersible electropump

Insulation must be measured with the relative instrument (500 V DC) before and after the
electropump is put in the water, assembled at the site of use.
→
Before submersion, connect a measuring cable to the earth wire.
→ Make certain the contact zones are clean.
→
Connect in series the other measuring cable with each wire of the cable connected to the
motor.
Insulation resistance is measured by the insulation measuring instrument.
Minimum insulation resistance with extension:
• with a new motor > 20 MΩ
Minimum insulation resistance without extension:
• with a new motor > 500 MΩ
→ Before connecting the motor electrically, make certain the system is completely disconnected
from the power and that when working no one can accidentally turn the power on.
Pay attention to the data on the rating plate and size the electrical equipment accordingly. The
connection examples given in this chapter refer to the motor itself and are not a suggestion
concerning the control elements installed upstream.
All the actions in the previous chapter have been done correctly.
L1 L2 L3
Electrical
U1 V1 W1
panel
Connection
U1 V1 W1
L1 L2 L3
U1 V1 W1
Connection
U1 V1 W1
Before installing the submersible electropump it's necessary to respect the following
safety rules:
→ Clean the well from sand or grit by applying the normal cleaning procedures.
→
Fit a stub pipe on to the pump delivery after having fitted the support bracket in two
halves to the other end. Make sure to clamp the screw (if it is present) on the
electropump to avoid the risk of backing off.
CONNECTION FOR STAR-DELTA START
Power leads
Motor leads
CONNECTION FOR DELTA START
Electrical
panel
Power leads
Motor leads
23
L1 L2 L3
Electrical
U1 V1 W1 U2 V2 W2
panel
Connection
U1 V1 W1 U2 V2 W2
L1 L2 L3
Electrical
U1 V1 W1
panel
Connection
U1 W2 V1 U2 W1 V2
EN