Troubleshooting Guide for Markon Generators TB055static.mcelroy.com/distributor/bulletins/TB055.pdf · Troubleshooting Guide for Markon Generators TB055 6. Next cut out the piece

Technical Bulletin: TB055 1 04/14/09

Troubleshooting Guide for Markon Generators TB055

Bulletin Number: TB055 Type of Bulletin: Trouble Shooting Products Affected: TracStar 500 & TracStar 500II Dates Manufactured: All Date of Notification: April 2009 Description of Bulletin This is a troubleshooting guide for Markon generators (MMI P/N: MDC00023; Markon P/N: BL105F) installed on the machines listed above. Reason for Bulletin To evaluate the generator for proper operation and provide instructions for diagnosing and limited repair.

Tools Required • True RMS Digital Multimeter with

capacitance measuring capability (ex. Fluke 87V)

• Cross tip screwdriver (Phillips™) • Flat tip screwdriver

• Needle-nose Pliers • Tin snips • 1/4" combination wrench • No. 2 Phillips™ tip driver bit

Procedure

Check Generator Output 1. Disconnect the heater. 2. Start the engine and set it to high speed. 3. Observe voltmeter on junction box located on top of the generator (see Figure 1). It

should display 230(+/-5). Adjust the engine speed, if necessary, to achieve 230(+/-5). 4. If voltage cannot be adjusted within range, or if no voltage is displayed, stop the engine

and remove the junction box cover.

Automated T500II T500 and T500II

Figure 1

5. Locate generator output wires. See Figure 2. Verify that the brown wire (U5) is securely connected to the white wire (U2).

6. Start the engine and set it to high speed.



7. With the True RMS meter, measure the voltage from the red wire (U1) to the blue wire (U6). You should be able to insert the meter probes into the crimp splices far enough to contact the wire. The voltage should be 230(+/-5) AC. Adjust the engine speed, if necessary, to achieve the proper voltage.


(U1 = Red wire; U2 = White wire; U5 = Brown wire; U6 = Blue wire) Figure 2

8. If the voltage cannot be adjusted to 230(+/-5), stop the engine and proceed to Check

Residual Voltage procedure. 9. If the voltage is correct, then the generator is functioning properly. If there is a problem

getting voltage to the heater, troubleshoot the circuit breaker, wiring and connectors downstream of the generator. For automated machines, also troubleshoot the heater control circuitry, solid state relay, Coach boxes and RTD circuit.


(circuit breaker terminals will have Black insulated wires soldered to them) Figure 3

10. Troubleshooting complete.



Check Residual Voltage

1. Stop engine and unplug heater. 2. Remove the two screws securing the plastic generator cover and rotate it 180° to check

for a cut out in the cover. If it is not present than one must be cut. 3. Partially install the screws allowing approximately 1/4" gap between the end of the cover

and the generator housing (see small arrows in Figure 4B). 4. Locate the first 2” cut as shown in Figure 4A just to the right of the bearing support shown

in Figure 4B. (It may be necessary to unbolt junction box mounting plate and move slightly to make first cut, as shown with the upper arrow in Figure 4A.)

4A – Location of first cut (lower arrow) 4B – Arrow points to bearing support (small

upper arrows show the 1/4" gap) Figure 4

5. Make a second parallel cut of the same length 4-3/4” to the left of the first cut (see Figure

5A and 5B).

5A – Location of second cut 5B – Second cut complete (line shows first cut)

Figure 5



6. Next cut out the piece between the two initial cuts leaving a cut out as shown in Figure 6.

Distance between the arrows is approximately 4-3/4”

Figure 6

7. Remove the generator cover screws. Rotate housing so that cut out is on bottom. Lift generator cover up to remove it from the generator.

8. Unplug both wires from the capacitor. (see Figure 7).

Bold arrows pointing to capacitor leads; fine arrows pointing to the field flashing terminals.

Figure 7

9. Start the engine. 10. Measure the AC voltage from the red wire (U1) to the white wire (U2) inside the generator

junction box, (see Figure 2). It should be at least 1.5 volts. If not, stop the engine, reconnect the capacitor leads to the capacitor and proceed to Field Flashing procedure.



Field Flash

1. Field flashing can repair generators with a certain type of fault. 2. Obtain two pieces of electrical wire long enough to reach from the generator to the

battery. 3. Connect one of the wires to one of the vacant capacitor terminals. (see Figure 7). 4. Connect the other wire to the remaining vacant capacitor terminal 5. Strip about 1/4” of insulation from the free ends of the two wires. Secure or hold the wires

so that each exposed conductor does not touch anything. 6. Start the engine and set it to high speed. 7. For only ONE second, touch the wire ends to the 12V battery (one wire to the positive

terminal and the other wire to the negative terminal). 8. Let the engine run for a couple of minutes, then repeat the “Check Generator Output”

procedure to see if field flashing has repaired the generator. 9. If the generator output is not correct, kill the engine and proceed to the Check Stator

Resistance procedure. Check Stator Resistance

1. Turn engine off. 2. With meter set to the lowest ohms scale, hold the two meter leads together. The

displayed measurement is the resistance inherent in your meter and leads. 3. Measure the resistance from red wire (U1) to white wire (U2). It should be about 0.22 Ω

higher than the meter resistance measured in step 2. 4. Measure the resistance from brown wire (U5) to blue wire (U6). It should be about 0.22 Ω

higher than the meter resistance measured in step 2. 5. Disconnect the wires from the capacitor and measure the resistance from one capacitor

wire to the other capacitor wire. It should be about 0.62Ω. 6. If not acceptable proceed to Check Capacitor procedure.

Check Capacitor

1. Turn engine off. 2. Disconnect the wires from the capacitor.

3. Set meter to capacitance mode and measure from the capacitor terminal where one wire was connected to the capacitor terminal where the other wire was connected. It should be between 38µF and 42µF. If not correct, replace the capacitor.

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Troubleshooting Guide for Markon Generators TB055static.mcelroy.com/distributor/bulletins/TB055.pdf · Troubleshooting Guide for Markon Generators TB055 6. Next cut out the piece