Yale 524150797, Maintenance Manual

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Safety Precautions
WARNING
Put blocks under each side of the truck under the
drive unit frame. Position blocks on both sides of
the load wheels. The blocks must prevent the mo-
torized hand truck from falling and causing injury
or damage.
WARNING
The capacitor in the transistor controller can hold
an electrical charge after the battery is disconnec-
ted. To prevent electrical shock and personal in-
jury, discharge the capacitor before inspecting or
repairing any component in the MDU compart-
ment. Wear safety glasses. Make certain the bat-
tery has been disconnected. DO NOT use a screw-
driver to make a short circuit across the B+ and B-
terminals of the transistor controller.
WARNING
To avoid personal injury and prevent electrical
shock, perform the following steps before per-
forming any troubleshooting or adjustments, and
before connecting or disconnecting a handset or
Personal Computer.
WARNING
To avoid controller damage, always disconnect
the battery. Discharge the capacitor and never put
power to the controller with any power wire dis-
connected. Never short any controller terminal or
motor terminal to battery. Make sure to use proper
procedure when servicing the controller.
1. Block the lift truck so that the drive wheel is off the
floor. See:
• Periodic Maintenance 8000YRM1510
for lift truck model A249
• Periodic Maintenance 8000YRM1666
for lift truck model A245
2. Turn the key switch to the OFF position and dis-
connect the battery.
3. Discharge the capacitors in the controllers by con-
necting a 200-ohm, 2-watt resistor across the
controller's B+ and B- terminals using insulated
jumper wires. See Figure 1.
DO NOT short across
the motor controller terminals with a screwdriver
or a jumper wire. Remove the 200-ohm, 2-watt re-
sistor before reconnecting the battery.
1. CONTROLLER
2. POSITIVE CONNECTION
3. INSULATED JUMPER WIRES
4. 200-OHM, 2-WATT RESISTOR
5. NEGATIVE CONNECTION
Figure 1. Discharging Controller
Safety Precautions 0630 YRM 1503
2