Timing Of The Maintenance; The Correct Operating Temperature; Insulation Resistance Test - ABB AMG 0180 User Manual

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Wear safety gear such as glasses, shoes, hard hat and gloves and suitable
protective clothing to protect the skin. Protective creams should always be
used.
•
Spray-varnish equipment, the frame of the machine, and the windings should
be earthed during spray-varnishing.
•
Take necessary precautions when working in pits and cramped places.
•
Only personnel trained to do high voltage work can carry out a voltage test.
•
Do not smoke, eat, or drink at the work site.

7.6.2 Timing of the maintenance

There are three main principles for timing the winding maintenance:
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Maintenance of the windings should be arranged according to other machine
maintenance.
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Maintenance should be performed only when necessary.
•
Important machines should be serviced more often than the less important
ones. This also applies to windings that become contaminated rapidly and to
heavy drives.
NOTE: As a rule of thumb, an insulation resistance test should be done once a
A maintenance program for the complete machine, including windings, is
presented in Chapter 7.3. Maintenance program. This maintenance program
however, should be adapted to the customer's particular circumstances, i.e.
servicing of other machines and operating conditions as long as recommended
servicing intervals are not exceeded.

7.6.3 The correct operating temperature

The correct temperature of the windings is ensured by keeping the exterior
surfaces of the machine clean, by seeing to the correct operation of the cooling
system and by monitoring the temperature of the cooling air.
For air cooled machines it is important to monitor the cleanliness of the air inlets
and outlets.
If the machine is equipped with the temperature detectors, stator operating
temperatures must be monitored. Significant temperature differences among the
detectors or high temperature could be a sign of damage in the windings.

7.6.4 Insulation resistance test

During general maintenance work and before the machine is started up for the
first time or after long standstill period, the insulation resistance of stator and rotor
windings must be measured.
The insulation resistance measurement provides information about the humidity
and dirtiness of the insulation. Based upon this information, correct cleaning and
drying actions can be determined.
For new machines with dry windings, the insulation resistance is very high. The
resistance can, however, be extremely low if the machine has been subjected to
incorrect transportation and storage conditions and humidity, or if the machine is
operated incorrectly.
year. This should suffice for most machines in most operating conditions.
Other tests should only be conducted if problems arise.
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