Technical_reference - 第63页

Technical Service Manual 63 Revision Dat e: August 2004 The c onvey or m otor has illus trated one of the f ollowing sy m ptoms . 1) T he conveyor will not run 2) T he conveyor stops running 3) T he conveyor speed is uns…

Technical Service Manual 62 Revision Date: August 2004

PROBLEM WITH THE SIGNAL FROM THE CONTROLLER TO I/O BOARD

The conveyor will not run because there is a problem with the signal from the controller to the I/O board.

POSSIBLE CAUSES

Check the following in the order given for the source of the problem.

1 Check the Alarm Conditions displayed on the computer screen.

2 I/O relay board (Check for the led lit on A1-K12).

3 Connections from the controller to the I/O relay board A1

4 Controller board.

5 Encoder (check the signal levels)

NO SIGNAL TO DC DRIVE MODULE FROM THE I/O BOARD

The conveyor will not run because there is no signal from the I/O Board to the DC drive module.

POSSIBLE CAUSES

Check the following for a solution: the most likely is listed first;

1 An alarm condition.

2 The connections or cables from the I/O Board to the DC drive module.

3 The controller.

4 The software in the computer or controller.

See the Control ladder print for the circuit details.

THE CONVEYOR IS JAMMED

The conveyor is jammed. This is causing the conveyor either to not run or to stop running.

POSSIBLE CAUSES

If the conveyor is jammed, there is a mechanical reason for it. The most common reasons for conveyor jams are:

1 Lubrication problems on a chain or combo conveyor. If the chain is not lubricated at the appropriate

intervals, the conveyor may jam and stop.

2 Mechanical jam in the tunnel.

3 Misalignment of the sprockets or idlers.)

4 Conveyor clutch

5 Conveyor motor.

6 Excess belt or chain catching and hanging up on something under the oven.

* See the Preventive Maintenance Manual for recommended lubrication intervals.

CONVEYOR MOTOR DOES NOT OPERATE

Technical Service Manual 63 Revision Date: August 2004

The conveyor motor has illustrated one of the following symptoms.

1) The conveyor will not run

2) The conveyor stops running

3) The conveyor speed is unstable

POSSIBLE CAUSES

Since the conveyor subsystem is an Electro-mechanical system, check the mechanical components before replacing

electrical parts. Ensure that the belt is not hung up below the oven, or that a board is not jammed somewhere on the

conveyor. After confirming that the mechanical elements of the conveyor are in operating order, start troubleshooting the

electrical components

The most likely are listed first:

1) Conveyor motor.

2) DC drive module.

3) I/O Interface board.

4) E-STOP switches.

5) Electrical enclosure interlock switches.

6) K37, K38.

7) F50, F52, F55 (When tripped, causes complete power loss to oven).

8) Controller signal).

9) Controller.).

CONVEYOR DRIVE CLUTCH NEEDS ADJUSTMENT

The conveyor drive clutch needs adjustment and this is causing one of the following symptoms.

1) The conveyor will not run

2) The conveyor stops running

3) The conveyor speed is unstable

4) The conveyor “jerks” (motion is not smooth)

POSSIBLE CAUSES

The conveyor clutch is mechanically connected to the end of the conveyor motor shaft and serves as protection for the

motor if there is a jam that actually stops the conveyor belt/chains from moving.

Exercise extreme caution when working near the conveyor drive system.

The clutch is set at the factory to slip at 35 + 5 foot pounds as measured with a linear scale. With time, the torque setting

may change. The adjustment mechanism is a large nut that presses against the clutch disc to create tension. To

increase the tension, turn the nut clockwise, the opposite will decrease tension. Use a linear scale and a hook on a chain

pin or a conveyor belt loop to pull until the conveyor stops moving. Read the measurement on the scale. The scale should

indicate 35 + 5 foot-pounds. If the tension cannot be adjusted between 30-40 foot pounds, the clutch may need to be

replaced. Other possible causes for improper clutch operation are:

1) Mechanical or lubrication problems with conveyor shafts.

2) Conveyor belt or chains catching and/or dragging

3) Conveyor sprockets slipping

Technical Service Manual 64 Revision Date: August 2004

THERE IS AN AC CIRCUIT FAILURE IN THE CONVEYOR CONTROLS

There is an AC circuit failure in the conveyor controls, causing the conveyor to stop running.

POSSIBLE CAUSES

The electrical components, which could affect the conveyor system, are mostly switches and are in the circuits that

directly affect the conveyor operation.

1) I/O relay – (A! – K12)

2) A!-K1

3) E-STOP switches (4).

4) Electrical enclosure interlock switches.

5) F50, F52 or F55 (This will cause a complete system failure).

6) A1-K3.

7) DC drive module.

All of these components can be found on the Oven Schematic.

AN ALARM CONDITION HAS OCCURRED

An alarm condition has occurred and has stopped the conveyor.

POSSIBLE CAUSES

This may or may not indicate an actual component failure. The operator must look at the computer screen to see what

alarm message is displayed and take the appropriate action from there.

The conveyor stops on a critical alarm condition. The alarms that can be set to critical are listed below.

1) One or more E-STOP switches are pressed.

2) The computer is unable to communicate with the controller.

3) The bonnet is open while the oven is operating.

4) A cell heater is not reacting correctly to the power being applied to it.

5) The safety over-temperature unit has detected the temperature of a cell

exceeding a predefined level.

6) The temperature of a cell has exceeded a predefined safety level.

7) The conveyor has stopped.

8) A circuit breaker has tripped (opened).