Miller Axcess E Dual Owner's Manual page 45

K. Motor Communications Error
The motor board has lost communication with the PCM board PC4. Check cabling and cable routing for boom system
motor cable and secondary cables. Separate cable as much as possible.
Check if WFM board PC6 code is installed and if microprocessor is running. Check LED3 and LED4 on WFM board PC6.
Depending on the wire feed speed, check for 0-40 volts DC on J17-3 to J17-1. If there is no voltage present there, check
for 40 volts DC at J16-1 to J16-2. If voltage is present there and neither LED is lit (Red or Green), try to download WFM
code to welding power source. If neither LED turns on after downloading code and cycling power, replace WFM board
PC6.
If LED3 and LED4 are flashing Red or Green or they are solid Red, this indicates the WFM board is still not communicating
with the PCM board PC4. Be sure that the UIM board PC7 is on-line (two green LEDs lit).
Check all Devicenet grey harness connections between process control module PC4, UIM board PC7, and WFM
S
board PC6.
S Check process control module PC4 for +24 volts DC at 6-pin connector J6-2 (+) and J6-5 (−).
MOTR
If +24 volts is not present at the connector, proceed as follows:
S Disconnect connector J10 and J11 from WFM board PC6. Check for +24 volts DC at J10-2 (+) and J10-5 (−), and
J11-2 (+) and J11-5 (−). One of the two connectors must measure +24 volts DC to ensures that the Devicenet lines
COMM
are being sent from process control module PC4 to WFM board PC6. If +24 volts DC is present at either connector,
replace WFM board PC6.
S If +24 volts DC is not present at either J10 or J11 connector, check process control module PC4 at connectors J6, J7,
and J8.Remove plugs from connectors and check for +24 volts DC at pin2 (+) and pin 5 (−). If +24 volts DC is not
present at any of the connectors, replace process control module PC4.
If LED3 and LED4 are both green this indicates that the WFM board went off-line and then recovered which is usually due
to noise interference.
S Check wire drive motor isolation. Isolated portion of motor housing should not touch robot arm, welding power source
chassis, lifting eye bolts, or weld secondary common. Measure impedance between chassis and both weld secondary
commons. Measure the impedance across motor isolation barrier on motor housing. All measurements should read
high impedance.
S Check all Devicenet grey harness connections between process control module PC4, UIM board PC7, and WFM
board PC6.
L. Over Average Current Error
Output current is exceeding the thermal capabilities of the welding power source for approximately 25 seconds.
Default value is as follows:
Axcess 450 limit is 610 A average
This is a duty cycle error and requires 5 minutes with power on and NO welding to clear the error.
This error indicates that an excessive amount of current was drawn over a short period of time. Over-average current is
drawn for a period of approximately 25 seconds and can also be expressed as exceeding the power source duty cycle.
The current limit is as follows:
OVER Axcess 450 is 610 amperes
This alarm cannot be reset. To clear the condition, the power source must be turned on and allowed to idle for approxim-
ately 5 minutes. This cooling period is determined by an internal timer, and turn off power will not reset the timer since it is
AVE
saved with the Configuration data. After the 5 minute cooling period, press the Jog or Purge button, or cycle power to clear
the alarm.
If this alarm was received by mistake, and the power source did not exceed the duty cycle, check the following:
Check current feedback signal either while welding or connecting to a load bank. Measure between test point TP8 and
grounding strap on process control module PC4. Test point TP8 is located on left-hand side of board, about 1 in. (25 mm)
to the right of connector J11. TP8 is scaled: 1 volt measured equals 100 amperes actual. This measurement should read 0
volts when not welding. If the measurement reads approximately 13 volts DC, disconnect LEM device from engine (one at
a time) to determine if either device is bad. If the voltage reading still does not change, unplug the lower inverter control
board; if the reading remains the same, replace the upper inverter control board. Voltage readings should be present while
welding. If voltage readings are not correct for current feedback scaling, check individual inverter engines.
OM-248965 Page 41