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Technical Service Manual 61 Revision Dat e: August 2004 UNRELIA BLE OUT PUT FROM DC DRIVE M ODULE The DC drive m odule m ay be causing one of the f ollowing: 1) (No O utput) T he conveyor will not run 2) (No O utput) The…

Technical Service Manual 60 Revision Date: August 2004

FOR FUTURE USE

I/O RELAY HAS FAILED OR IS OFF

The conveyor will not run because the I/O relay has failed or is off.

POSSIBLE CAUSES

If the I/O relay has failed or is turned off, two items can be checked without a meter:

1. Is the relay properly seated in the I/O board?

2. Are both ends of the cable from the controller Interface board connected?

Refer to the schematics. The conveyor relay is number A1-K12 and connects to pins PX5-14 & Px5-15 on the I/O board.

Also, check the connections from the encoder and the DC drive. These are on A1, PX9 pins 1,2, & 3 on the controller

interface board.

The oven will “alarm” and shut down if the conveyor does not run, therefore it will be necessary to enable

“Conveyor Calibration” in Oven Operation Program for trouble-shooting to take place.

Technical Service Manual 61 Revision Date: August 2004

UNRELIABLE OUTPUT FROM DC DRIVE MODULE

The DC drive module may be causing one of the following:

1) (No Output) The conveyor will not run

2) (No Output) The conveyor stops running

3) (Intermittent Output) The conveyor speed is unstable

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

POSSIBLE CAUSES

The DC drive module is an electronic assembly that receives a control signal from the controller on pins +SIG and -SIG

and AC voltage on L1 and L2. This produces DC voltage on pins A1 and A2 at a level sufficient to power the Conveyor

motor at various speeds.

HINT: Check the following items when troubleshooting a faulty DC drive circuit.

The most likely are listed first:

1) DC drive module.

2) Conveyor motor.

3) I/O relay.

4) E-STOP switches.

5) K37 & K38.

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

7) Controller.

8) Speed – (If the conveyor is set less than 8”/min, the conveyor will become unstable

(DC motor, NOT stepper motor)

In addition to the items listed above, check the signals from the oven controller to help determine why there is no signal

from the DC DRIVE MODULE. The signals in question are listed on the Control ladder print as follows:

Analog Out Common (A1 Board PX9-18) (-SIG drive V1)

Analog Out 1 (A1 Board PX9-17) (+SIG drive V1)

(A voltage level between 0v and +10v should be found when checking these two signals with a voltmeter. Place

the negative lead on Analog Out Common and the positive lead on Analog Out 1)

Check the switches, circuit breakers and relays, to be securely mounted and that the wires are connected correctly* and

tightly.

When checking the drive motor, refer to the section on motor troubleshooting if the fault is not obvious.

The final test will be to replace the DC Drive Module after all other possibilities have been eliminated.

* Use the oven schematics to verify correctly connected wires.

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