Technical_reference - 第60页

Technical Service Manual 60 Revision Dat e: August 2004 FOR FUTURE USE I/O RELA Y HA S FA ILED OR IS OFF The c onvey or will not run because the I/O relay has failed or is of f. POSSIBLE CAUSES If the I/O r elay has fail…

Technical Service Manual 59 Revision Date: August 2004

CONVEYOR HAS NO POWER

The conveyor will not run

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 transformer secondary (F52) supplies power to ALL control circuits including the DC drive module.

One of the following is likely to be responsible:

1) F50, F52.

2) DC drive module.

3) Conveyor motor.

4) RT1 (motor inrush current limiter)

5) A1 I/O board (conveyor relay A1-K12).

6) Short in the wiring.

7) F67

K37 & K38 DOES NOT OPERATE

The conveyor will not run because K37 & K38 will not energize.

POSSIBLE CAUSES

If K37 & K38 will not energize, the conveyor will not operate.

Check the following components.

1) E-STOP switches.

2) G2 24vdc Power Supply.

3) Electrical enclosure interlock switches

4) K37 & K38.

5) F50, F52.

6) F55

The on/off/stop circuit consists of the E-STOP switches, K37 & K38, F50, F52, and F55 as well as the wiring and terminal

strips connecting the components.

HINT: First check the devices physically: the E-STOP switches should be “up”. K37 & K38 should be energized, and F50,

F52 and F55 should be “closed”. (not tripped).

After a physical check, check the wire connections... look for them to be tight and correctly connected. If any repairs were

recently been performed in this area, look for a device that may have been improperly connected when the work was

done.

Finally, check all components electrically with a volt-ohm meter for correct voltage and internal resistance. NOTE: If F50,

F52 or F55 open (trips), the entire oven will lose power.

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.