Yale MPB040-E, Manual

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Electrical System Checks
SAFETY PRECAUTIONS
NOTE: On some models, the dash indicator will dis-
play the code: EP 107 (or a higher number) for 1 to 2
seconds every time the key switch is turned to the ON
position. This code represents the EEPROM software
version and DOES NOT INDICATE A FAULT CODE.
NOTE: These checks require a volt-ohmmeter. Spe-
cific checks require additional equipment.
NOTE: The correct meter polarity is necessary for
the checks. The voltage checks are made between
the individual points and battery negative. Connect
the meter negative to battery negative.
1. Block lift truck so the drive wheels are off the
floor. See the section
Periodic Maintenance
8000YRM1048, Periodic Maintenance
8000YRM1009, or Periodic Maintenance
8000YRM1379 lift trucks. Refer to How to Put a
Lift Truck on Blocks.
2. Turn the key switch to the OFF position.
3. Disconnect and separate the battery connectors.
4. Remove the upper drive unit compartment cover.
5. Remove the lower drive unit compartment cover.
6. Discharge the capacitor. See Special Precau-
tions.
7. Check the specific gravity of the battery. If the
specific gravity is less than 1.260, the battery is
not fully charged or is damaged. A fully-charged
battery has a specific gravity of 1.270 to 1.290. A
discharged battery has a specific gravity of ap-
proximately 1.165.
8. The truck has an isolated electrical system; nei-
ther battery terminal is connected to the truck
frame. Check for 50,000 ohms or more between
each terminal, one at a time, of the battery con-
nector of the lift truck and a clean connection on
the frame. Remove any circuit paths between the
controller and the frame of the lift truck, such as a
dirty battery case. Carbon dust in a motor or other
parts can cause a circuit path. Check for addi-
tional equipment that may cause a circuit path to
the frame.
9. Check for voltage between each terminal of the
connector that fastens to the battery and a clean
connection on the frame. Normally there is small
voltage (less than 30% of the battery voltage) be-
tween the battery and the frame, even though the
resistance is very high. A higher voltage can indi-
cate a dirty or damaged battery. Clean battery
and battery compartment as necessary.
10. Visually check for parts or wires that are loose or
damaged.
NOTE: Make an identification of any wires before you
disconnect them. The wires must be connected cor-
rectly after checks or repairs.
Electrical System Checks 2200 YRM 1007
8