Nidec LSA 52.3 - Rotary Diode Bridge Test; Coil Cleaning; General Information; Coil Cleaning Products

Electric Power Generation
Installation and maintenance
5382 en - 2022.11 / h
LSA 52.3 / LSA 53.2 / LSA 54.2
Industrial Range Alternators
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27


=

(t=10minutes)

(t=1minute)
Polarisation index Diagnostic Action
p
i
< 1 Poor Intervene
1 <
p
i
< 2 Fair Monitor
2 <
p
i
< 4 Good Nothing to
report
p
i
> 4 Very good
Nothing to
report
5.9 ROTARY DIODE BRIDGE TEST
Carry out the test using a D.C. source as indicated below.
A diode in good condition should allow the current to flow
only in the anode-to-cathode direction.
Disconnect the diodes before the test.
3 ... 48 volts
+
-
1
2
1 - Anode
2 - Cathode
Diode type Positive Negative
SKR diode housing diode wire
SKN diode wire diode housing
When reassembling, ensure that the diodes are tightened
to the correct torque.
5.10 COIL CLEANING
5.10.0 General information
The cleaning of the winding is a very demanding operation
which must be carried out only if necessary.
The cleaning of the windings become necessary as soon
as the insulation resistance and/or the polarisation index
are not satisfactory (refer to chapter 5.8.2).
5.10.1 Coil cleaning products
Effective long-term cleaning can only be performed in a
workshop with specialised equipment.
A site cleaning, because less efficient, can be considered
only for a transient period.
CAUTION:
USED CLEANING AGENT MUST BE IN ACCORDANCE
WITH LOCAL REGULATION AND ENVIRONMENTAL
STANDARDS.
CAUTION:
SOLVENTS, WHICH ARE HIGHLY CHLORINATED AND
SUBJECT TO HYDROLYSIS IN DAMP ATMOSPHERES
ARE PROHIBITED. They quickly become acidified,
producing corrosive and conducting hydrochloric acid.
CAUTION:
DO NOT USE TRICHLORETHYLENE,
PERCHLORETHYLENE, OR TRICHLORETHANE.
Avoid mixtures sold under various trademarks which often
contain white spirit (which evaporates too slowly) or
chlorinated products (which are likely to become acidified).
CAUTION:
DO NOT USE TOO STRONG ALKALINE PRODUCTS.
THEY ARE DIFFICULT TO RINSE AND CAUSE
REDUCTION OF INSULATION RESISTANCE BY
ATTRACTING MOISTURE.
5.10.2 Cleaning Operation
Use a mild alkaline product or a dedicated cleaning
product.
We recommend the use of the cleaning agent "ASOREL
CN" from "Rhône Chimie Industrie"; 07300 Tournon;
France. This cleaning agent Does not require any rinsing
operation.
It is essential to avoid entry of cleaning agents and dirt into
the notches. Apply the product with a brush, sponging
frequently in order to avoid accumulation in the housing.
After cleaning, a rinsing operation must be performed. Hot
soft water (less than 80°C) used under pressure (less than
20 bars) can be used.
CAUTION:
AFTER CLEANING THE GENERATOR, DRYING IS
ESSENTIAL FOR RECOVERING THE CORRECT
WINDING INSULATION.