KSB Amacan P 500-270 Installation & Operating Manual page 51

Temperature sensors in the
motor winding
3 Optional
7 Servicing/Maintenance
On pump sets with sacrificial anodes, the sacrificial anodes must initially be checked
after 6 months. If necessary, the sacrificial anodes must be replaced. If the sacrificial
anodes show little wear, the maintenance interval can be extended to 12 months.
7.2.1 Inspection work
7.2.1.1 Measuring the insulation resistance
Measure the insulation resistance of the motor winding during annual maintenance
work.
ü The pump set has been disconnected in the control cabinet.
ü Use an insulation resistance measuring device.
ü The recommended measuring voltage equals 500 V (maximum permissible
1000 V).
1. Measure the winding to chassis ground.
To do so, connect all winding ends together.
2. Measure the winding temperature sensors to chassis ground.
To do so, connect all core ends of the winding temperature sensors together
and connect all winding ends to chassis ground.
ð The insulation resistance of the core ends to chassis ground must not be lower
than 1 MΩ.
If the resistance measured is lower, power cable and motor resistance must be
measured separately. Disconnect the power cable from the motor for this
purpose.
NOTE
If the insulation resistance of the power cable is lower than 1 MΩ, the power cable
is defective and must be replaced.
NOTE
If the insulation resistances measured on the motor are too low, the winding
insulation is defective. The pump set must not be returned to service in this case.
7.2.1.2 Checking the sensors
CAUTION
Excessive test voltage
Damage to the sensors!
▷ Use a commercially available ohmmeter to measure the resistance.
The tests described below measure the resistance at the core ends of the control
cable. The actual sensor function is not tested.
Table 9: Resistance measurement
Measurement between terminals ...
10 and 11
3)
31 and 32
Amacan P
Resistance
[Ω]
200 - 1000
100 - 120
51 of 112