Lorentz PSk2-7 Manuel D'installation Et De Fonctionnement page 43

Winding resistance
1. Set the multimeter to "resistance measurement" and
select the lowest measuring range.
2. All PSk2 motors are 3-phase motors. Measure the
resistance of phase-to-phase: L1-L2, L2-L3, L3-L1.
Make sure there is good contact between the probes
and the cable.
3. The deviation between the phases should be within
10 %. If the deviation is too high, the reason is likely a
damaged submersible cable or a faulty cable splice.
4. The absolute value is made up of the resistance of the
motor winding and the submersible cable. The resist-
ance of the submersible cable depends on its length
and size. For copper cable, the values of the table
below, "Table 7: Motor cable resistance" and "Table
8: Motor resistances for submersible pump motors"
on page 42 can be used as approximation.
Table 7: Motor cable resistance
Cable
4 mm / AWG 11
2
6 mm / AWG 9
2
10 mm 2 / AWG 7
16 mm / AWG 5
2
Example:
ƒ Motor:
ƒ Motor cable:
Calculation of expected phase-to-phase resistance:
= 1.8 Ω + 2 × 150 m × 0.25 Ω / 100 m
= 1.8 Ω + 2 × 0.375 Ω
= 1.8 Ω + 0.75 Ω
= 2.55 Ω
= ~ 2.6 Ω
The real measured values can be different, depending on the
measurement equipment and materials that are used. This is
just an approximation.
Insulation resistance
Use a megohmmeter at 500 –1,000 V.
Measure each phase to ground. Connect one test prod to
the phase hold the other test prod to the pipe work, or if
Resistance
plastic pipes are used to the ground wire.
[Ω / 100 m]
If the insulation resistance is below 0.5 MΩ ,the motor
0.40
cable must be ckecked for damage.
0.25
0.17
0.10
Pump Installation
AC DRIVE SUB 6" 7.5 kW  1.8 Ω
150 m and 6 mm  0.25 Ω / 100 m
2
41