SAFETY
Safety - 19
3400
Safety Procedures
Operator Safety Interlock System
The 3400 power unit is equipped with a safety interlock system. This system:
• Prevents the engine from starting unless the parking brake is engaged.
• Prevents the PTO from starting if the operator is not in the seat.
• Prevents the power unit from driving if the parking brake is engaged.
•
Shuts off the PTO if the operator leaves the seat.
•
Shuts off the engine (and fuel pump) if the operator leaves the seat without engaging the parking brake.
Testing the Safety Interlock System
WARNING
Never operate the power unit if the safety interlock
system is malfunctioning. Do not disengage or bypass
any switch. Failure to heed warning could result in
injury to yourself and others, or damage to property.
CAUTION
The daily inspection should be performed prior to
initial startup for the day.
Perform the following safety interlock tests daily. Before testing, park the power unit on a level surface,
place wheel chocks in front and back of wheels, and place the high/low range shift lever in the neutral
position. After testing is complete, place the high/low shift lever in either high or low range, set the parking
brake, and remove the wheel chocks.
Tests 1-3
test the ‘Engine Start’ function. For each test, turn the key to the RUN position (do not start the
engine). As listed for each test, engage or disengage the parking brake and sit on the seat or raise body
weight from seat. The engine starter should or should not engage as described for each test.
Tests 4-6
test the ‘Engine Run’ function. For each test, start the power unit so that the engine is running. As
listed for each test, engage or disengage the parking brake and sit on the seat or raise body weight from
seat. The engine should continue running or stop running as described for each test.
Tests 7-10
test the ‘PTO’ function. For each test, turn the key to the RUN position (do not start the engine).
As listed for each test, place the PTO switch in the ON or OFF position and sit on the seat or raise body
weight from seat. The electric PTO clutch will make an audible noise when it engages or disengages.
Engine
Start
Test Number
Parking Brake Engaged
Operator Present in Seat
Engine Starts
1
No
Yes
No
2
Yes
No
Yes
3
Yes
Yes
Yes
Engine
Run
Test Number
Parking Brake Engaged
Operator Present in Seat
Engine Runs
4
Yes
Yes
Yes
5
Yes
No
Yes
6
No
No
No
PTO
Test Number
PTO Switch
Operator Present in Seat
PTO Clutch
7
Off
Yes
Off
8
Pull to ‘On’ Position
No
No
9
Pull to ‘On’ Position
Yes
Yes
10
On
Raise Operator Body Weight from
Seat
PTO Disengages
(1/2 second delay)
If the power unit fails any one of the safety interlock tests, refer to the troubleshooting section for using the
TCM (tractor control module) to diagnose electrical problems.
