TeeJet ARC-6000 - Manual (Page 33)

6-1
98-05017
Rev.- 1
ARC 6000
CE & S TANDARD V ERSION
6.0. EMERGENCY OPERATIONS
MIDWEST TECHNOLOGIES has gone to great lengths to make the ARC System as fool proof and reliable as possible. However,
we recognize that things break from time to time, despite our best efforts. If the operator does experience a failure of the ground
speed sensor, the main flow control valve or, the flowmeter (or rate sensor), the first thing to do is to carefully check the wiring
harnesses for obvious breaks and follow the suggested troubleshooting advice outlined in Section 5.0. in this manual. Assuming
there is no success in attempts to get the failed component to respond, MIDWEST TECHNOLOGIES suggests the following
procedures as a temporary measure until the component can be fixed or replaced.
If the operator chooses to follow one of the following procedures, he should recognize that the accuracy of application is
reduced. If this reduced accuracy is acceptable, these procedures will allow the operator to continue on a temporary basis.
6.1. GROUND SPEED SENSOR FAILURE
The control console has an internally generated speed signal when operated with the GSO function activated. When the unit
is operated in the GSO speed mode, the control console will establish the APPLICATION RATE as if the vehicle were actually
moving across the field at the programmed GSO speed, even though there is no real speed input. This feature can be used to operate
the sprayer under a reduced accuracy, in the event of a failure of the speed sensor.
A. With all boom section solenoid switches OFF, Power ON, Mode Selector in the SET-UP position and the vehicle
stopped, rotate the Display Selector to the SPEED position. Using the INC/DEC switch, set the ground speed override
speed for the normal spraying speed, (See Section 2.10. for additional information).
B. Set the Mode Selector switch back to OPERATE. Start the vehicle and steer toward the desired swath, accelerating to
normal application speed (as close as possible to the GSO speed value). As the vehicle reaches the start of the desired
swath, turn on the booms and begin applying. BE SURE THE GSO SWITCH IS TURNED ON.
C. The control console will control application as if the vehicle were moving at the established GSO speed. The actual
accuracy of application will therefore depend upon the ability of the operator to maintain the desired vehicle speed. If
the vehicle is traveling at exactly the established GSO speed, the application will be nearly exact. If the vehicle is
traveling faster or slower than the established GSO speed, the application rate will be under or over the desired rate by a
proportional amount.
D. The console will still keep track of the TOTAL APPLIED, and the system will adjust to changes in boom width.
These functions can be monitored on the display.
E. The ARC display will continue to flash a too slow message, and an audible alarm will sound ,to indicate abnormal
operation. There will be no speed displayed. Areas will not accumulate. Application rate information is meaningless.
F. MIDWEST TECHNOLOGIES RECOMMENDS THIS PROCEDURE AS AN EMERGENCY, TEMPORARY
PROCEDURE ONLY. THE PROBLEM WITH THE GROUND SPEED SENSOR SHOULD BE RESOLVED AS
SOON AS PRACTICAL SO THAT FULL CONTROL OF THE APPLICATOR CAN AGAIN BE ENJOYED.
6.2. FLOW CONTROL VALVE FAILURE (LIQUID APPLICATOR)
The ARC System can be operated at a reduced level of control in the event of a flow control valve failure. To operate the sprayer,
it will be necessary to manually adjust the flow control valve so that sufficient pressure is available to the booms to give a good
spray pattern. Thus, there is no longer positive control over the flow. Use the following procedure to manually position the flow
control valve.
A. With the vehicle stopped, turn all boom sections OFF, with Power ON, with Mode Selector in OPERATE, rotate the
Display Selector to APPLICATION RATE. Use the INC/DEC switch to set the application rate to 0.0.
B. Disconnect the flow control valve at the cable disconnect. If the valve has failed in an open position, allowing suffi-
cient flow to pass to keep a good pattern at the nozzles, no further action is needed to adjust the valve. If the valve has
failed in a closed or nearly closed position, it will be necessary to remove the electric actuator assembly and manually
rotate the valve stem to an open position. CAUTION: MARK THE VALVE POSITION TO START. FULL OPEN
TO FULL CLOSE IS ONLY A 90
0 ROTATION.
C. Turn ON the normal boom sections. Use a nozzle chart to determine the boom pressure that will give the desired