Mec 3072RT, Руководство по обслуживанию

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"3072RT / 3772RT / 3772RT HD" Service & Parts Manual - ANSI Specifications March 2008
Page 4-3
TROUBLESHOOTING
The 3072RT and 3772RT are designed for ease of diagnostics. There is a terminal strip located
under the work platform for checking signals to and from Upper Controls. There are also LED’s
located in the Lower Controls box to indicate outputs from the circuit board.
Diagnostic Example: if the lift LED does not illuminate when attempting to lift, either the main
power is not on, or board is not receiving a signal for lift. If LED is illuminated but machine does
not lift, there would be an electrical problem between the Circuit board and the valve, or a
hydraulic problem. The main valve block is equipped with a quick disconnect gauge port to help
diagnose the hydraulic system.
General Troubleshooting Tips
Before investigating a malfunction, check the following items:
• Check that battery switch is turned on.
• Check that battery connections are secure and battery if fully charged.
• Check that the emergency stop button is released (UP/OUT position).
• Check that the hydraulic fluid is at the correct level.
• Check that the circuit breaker is in the “ON” position (not tripped).
Common Causes of Hydraulic System Malfunctions:
• Incompatible hydraulic fluids mixed, destroying the additives and causing varnish build
up, resulting in the valves sticking.
• Water in the hydraulic fluid due to a damp climate.
• Improper hydraulic fluid used. Viscosity too high in cold climates. Viscosity too low in
warm climates.
• Hydraulic oil contaminated with debris - filter change interval neglected.
NOTE: Mobil Fluid 424 Hydraulic Oil, is a multiple viscosity oil that is light enough for
cold climates and resists thinning in warm climates. Only Mobil Fluid 424 or
equivalent must be used. Substituting with a lower grade oil will result in pump
failure.
Following is a step by step basic troubleshooting guide.
NOTE: Contamination always causes failure in any hydraulic system. It is very important
to be careful not to introduce any contamination into hydraulic system during the
assembly procedures. Please make sure all ports and cavities of the manifold and
cylinders are properly covered/plugged during maintenance activities.