Installation manual
Diagnostics and Troubleshooting 55
Safety Information Product Overview Installation Diagnostics
Options and
Accessories
Specification
NVM Invalid
At power-up the drive tests the integrity of the non-volatile memory. This fault is generated if the contents of the non-
volatile memory are invalid.
Invalid Configuration
This fault will occur if the digital board in the drive does not match the power board settings. It is only useful during
manufacturing. A drive with this fault should be returned for service.
Drive Overtemp
Indicates the drive internal temperature has reached an over temperature condition - not currently implemented in
the EP202, EP204 or EP206 models. For Epsilon EP209 and EP216 drive models, this fault will occur if the soft-start
circuit has failed or mis-wiring of the bus or shunt prevents proper start-up, resulting in overheating the soft-start
resistor internal to the drive. With the EP216 model this over temperature condition could be the result of fan failure.
Power Module
This fault is generated when a power stage over-temperature, over-current or loss of power stage logic supply
occurs. This can be the result of a motor short to ground, a short in the motor windings, a motor cable short or the
failure of a switching transistor.
High DC Bus
This fault will occur whenever the voltage on the DC bus exceeds the High DC Bus threshold. The most likely cause
of this fault would be an open external shunt, a high AC line condition, or an application that requires an external
shunt (e.g., a large load with rapid deceleration) but none is installed.
Low DC Bus
This fault will occur whenever the voltage on the DC bus drops below the Low DC Bus threshold. The most likely
cause of this fault is a reduction (or loss) of AC power. A 50 ms debounce time is used with this fault to avoid faults
caused by intermittent power disruption. With an Epsilon EP drive, the low DC bus monitoring can be disabled. In an
EP-B and EP-I this fault is disabled by clearing the check box on the Faults view, and for an EP-P the check box is
located on the Advanced view
Special note for EP209 and EP216 drives, the Low DC Bus fault may not be disabled. The bus voltage must reach
140 Vdc (100 Vac input) before this fault will reset and it will reset automatically. It will occur again when the bus
voltage drops by 50 V from the voltage on the bus when soft-start mode ends and the drive is ready to run.
Encoder State
Certain encoder state transitions are invalid and will cause the drive to report an encoder state fault. This is usually
the result of noisy encoder feedback caused by poor shielding. For some types of custom motors it may be necessary
to disable this fault. With an Epsilon EP drive, the Encoder State monitoring can be disabled. In an EP-B and EP-I
this fault is disabled by clearing the check box on the Faults view, and for an EP-P the check box is located on the
Advanced view.
High DC Bus Threshold
Epsilon EP 415 Vdc
Low DC Bus Threshold
Epsilon EP 60 Vdc