Operation
36
Auto Reset Function (continued)
5.5.2 Two-Wire, Three-Wire and Communications Control
The Auto Reset operates with Two-Wire, Three-Wire and communications start/stop. Generally, this is not
a problem if the control supply is maintained, although warning should be given that in Three-Wire and
communications control the motor may start without a direct start signal. (Although it is implied as no stop
had been given during the reset delay period).
5.5.3 Control Supply Loss
When the control supply is removed the microcontroller is unable to make calculations in real time. To
overcome this the calculations are made retrospectively when the starter powers up.
Two Wire
: Following a control supply loss the Start signal must be retained (Fig 5.6.2).
Three Wire
: The state of the start signal is saved when the control supply is removed and if it was set to
‘start’ the Auto Reset will continue at power up. When operating in this mode the motor may start at power
up without a start signal being present (Fig 5.6.3).
5.5.4 Modbus/Communications
The state of the start signal is saved when the control supply is removed and if it was set to ‘start’ the Auto
Reset will continue at power up. When operating in this mode the motor may start at power up without a
start signal being present (Fig 5.6.3).
Auto Restart Termination:
If the time to re-establish the power exceeds the Reset Delay x Reset Attempts
the Auto
Reset terminates.
5.5.5 Overload Trip
Following an overload trip, the overload will at 100% and then cool exponentially to 0% after several
minutes.
If a restart is attempted too soon the starter will trip again as the overload would not have cooled to a
sufficient level (Fig 5.6.5).
It must be ensured the Reset Delay is long enough to allow the overload to cool. This is also the case for
the heatsink over temperature trip.
5.5.6 Remote Start on Trip
If Auto Reset is turned on the Remote Start On trip trips are disabled and will be ignored.
5.5.7 Hand/Auto
If the Hand Auto option is selected the Hand Selection will override the Auto Reset.
The Auto Reset will be terminated, and the counters will be re-initialised.