EP Equipment EPT20-15ET, Руководство по обслуживанию

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61
REV. 09/2016
HYDRAULIC SYSTEM
7
7.4.2 Checking and Testing
Checking
-
Check if the pump contactor and appearance
of cables are in good condition, and if the
plug connection is secure;
-
Carry out ON/OFF test to contacts of pump
contactor with a multimeter:
If connected, but with contactor adhesion,
replace the contactor;
If not connected, move on to the next step;
Testing
-
Switch off the power supply of the vehicle;
-
Measure the resistance between pump
contactor coil end point A and B to identify if
the coil is normal;
As shown in the following table:
Resistance
Measurement
Judgment
Approx. 22 Ω Normal
0 Ω
Coil shorting
(replace the contactor)
∞
Ω
Coil breaking
(replace the contactor)
-
Energize the contactor coil between end point
A and B (24V):
If the contact is not absorbed (without the
sound of absorption), the contactor is having
mechanical failure with its contact, replace
the contactor;
If the coil is normal, move on to the next step.
7.4.3 Control Circuit Troubleshooting
Pump Contactor Control Circuit
(Figure 10301)
Check if the circuit is broken by using a multi-
meter:
-
-
Set the multimeter to ON-OFF;
Check if #5/#9 circuit is conducted.
If the contact is absorbed (with the sound
of absorption), and contact C and D are
conducted, then the contactor is working pro-
perly.
Pump Contactor
Key Switch
Lifting Limit Switch