Miller Auto-Axcess E Digital, Owner'S Manual

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OM-257 675 Page 98
H. No Tach Error
ERR
TACH
Indicates loss of tachometer feedback. Determine cause of error as follows:
S Press JOG button on the front panel.
S Does the motor run wide open immediately?
S
YES Replace Motor Board PC6.
S
Does the motor ramp up in speed?
S YES Bad motor tach. Contact nearest Factory Authorized Service Agent.
S Does the motor respond at all?
S YES Contact nearest Factory Authorized Service Agent.
S Check motor cable. Is it damaged?
S YES Replace motor cable.
S NO Contact factory service personnel.
I. Thermal Over Temperature Error
ERR
TEMP
Indicates one or more of the inverter engines overheated. Sent from inverter engine module(s) (RC6, Pin 12, on inverter
control board PC1) to process control module PC4 (J2, Pin 7). Check fan on inverter engine(s) and weld currents.
This signal is the sum of two conditions: shutdown that comes from the temperature monitoring circuit on the inverter con-
trol board, and Pwr-Up-Cnt that generated by the boost section of the inverter control board. When either of these signals
is active, RC6-12 is pulled low (this is the not ready line out of the inverter control board).
Shutdown is active when there is an over-temperature condition on the primary or secondary heatsink or on the boost
inductor. To determine which of the two locations is at fault, check LED 1 and LED 2 on inverter control board PC1.
S If LED 1 is lit, this indicates an over-temperature condition on the primary heat sink.
S If LED 2 is lit, this indicates an over-temperature condition on the secondary heat sink or on the boost inductor.
Pwr-Up-Cnt (power up control) monitors primary voltage start-up conditions when the power source is first turned on. This
signal is opto-isolated from the boost section of the inverter control board. The following conditions must be met for the
power source to power up:
S Auxiliary power board PC3 must be powered up and operating to supply prepower of +15 volts DC to the boost sec-
tion of inverter control board PC1.
S The peak voltage of the input line power must be greater than 150 volts peak.
S The DC bus voltage must be greater than 85% of the rectified line voltage. This bus voltage also turns on the
pre-charge relay.
S The DC bus voltage must be boosted to greater than 858 volts DC.
If any of these conditions are not met, then receptacle RC6-12 is pulled low and weld output is locked out.
J. Unknown Error
ERR
UNKN
Indicates error bit from process control module PC4 is set, but error value sent does not match anything defined with the
UIM board PC7.