EP Equipment EPT20-15ET, Руководство по обслуживанию

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59
REV. 09/2016
HYDRAULIC SYSTEM
7
7.3.2 Faults and Causes
-
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After replacing the steering motor or carbon
brush, conduction test must be carried out to
the motor (see Section 7.3.3).
After replacing carbon brush, running opera-
tion must be carried out to the carbon brush:
By running the motor with repeated lifting,
letting the carbon brush to be fully running,
making its surface smooth to
fi t the rotor.
Adjustment
1
Fault Motor does not rotate
Cause
a. Negative electrode cable
broken;
b. Motor positive and negative
electrode with loose terminals;
c. Armature winding with broken
circuits;
d. Motor bearing damaged and
blocked;
e. Serious wearing of carbon
brush.
2
Fault Motor speed is turning slow
Cause
a. Insuf fi cient voltage of battery;
b. Carbon brush worn or carbon
brush spring pressure
decreases;
c. Bearing wear or lack of
lubricating oil;
d. Armature winding has short
circuit elements;
e. Carbon brush winding grounded.
3
Fault
Motor sometimes can start,
sometimes cannot
Cause
a. Motor positive and negative
electrode with loose terminals
and poor connection;
b. Carbon brush wear and tear;
c. Armature winding has circuit
broken unit.
4
Fault
Motor with abnormal noise or
vibration
Cause
a. Uneven clearance between
stator and rotor;
b. Bearing failures;
c. Loosening
fi xing screws on
motor housing.
5
Fault Motor smoking or burning smell
Cause
Stator winding short circuit, motor
burnt
6
Fault Excessive temperature rise
Cause
a. Stator winding short circuit;
b. Motor positive and negative
electrodes with surface
oxidation, resistance increases
and results in heating;
c. Bearing failure, resulting in
severe heating.
7.3.3 Checking and Testing
Checking
-
Check if the pump motor and appearance of
cables are in good condition, and if the plug
connection is secure;
-
Check if the circuit is connected.
-
Carry out ON/OFF test to motor positive and
negative electrodes with a multimeter:
If connected, the motor is normal;
If not connected:
1) Broken circuits in rotor coils (replace the
motor);
2) Carbon brush wearing, move on to the
next step.
Testing
-
Replace the carbon brush (See Section
7.3.1).
When replacing the carbon brush, replace the
complete set of carbon brushes.
CAUTION
-
Remove the cables on the pump motor;