MPC2000D
Issue 2 22/4/98
Page
21
Low Set Overcurrent
This setting is not in service during starting. It can be set between the range of 100 and 500% in steps of 10% of FLC
to afford the user a faster tripping time for overcurrent conditions than that available from the overload curve. The
default for this setting is 400% of FLC. This feature can also be used to provide a fast operating definite time stall
protection after the motor is running.
Low Set Delay
This setting determines the time of the delay between the unit registering a low set overcurrent and an alarm or trip
being signalled. The setting is adjustable between the range of 0.5 and 10 seconds in steps of 0.5s, with a default
setting of 2.0 seconds.
High Set Overcurrent
This feature is normally enabled when the motor is being controlled by a circuit breaker rather than a fuse contactor.
The High Set Overcurrent unit can be set between the range of 400 and 1200% in steps of 10% of FLC, with a default
value of 800%.
High Set Delay
User set from the keypad, this setting determines the time between registering a High Set Overcurrent and an alarm or
trip being signalled. Adjustable between the range of instantaneous to 4 seconds in steps of 0.1s with a default setting
of 'Instantaneous'.
Overload Setting
Pre-settable overload setting range 60 to 130% in steps of 1% of FLC, with a default and P&B Engineering's
recommended setting of 105% of FLC. For further information refer to section 'MPC2000D Thermal Overload
Protection'
Thermal Capacity Alarm
User settable to specify a thermal capacity alarm value between the range of 50 and 99% in steps of 1% of capacity,
with a default setting of 80%.
t6x Time
This setting specifies the time the MPC2000D will take to trip at 6 times FLC and determine the basic thermal
characteristic. This time range 0.5 and 120 seconds, with a default setting of 10 seconds. For further information refer
to section 'MPC2000D Thermal Overload Protection'
Hot/Cold Ratio
Adjustable between 20 and 100% in steps of 1%, with a default setting of 50%. For further information refer to
section 'MPC2000D Thermal Overload Protection'
Cool Time Factor
This setting specifies the time factor at which the running motor will cool down once it has been stopped. Adjustable
between the range of 1 to 15 in steps of 1 times the heating constant with a default setting of 5. For further
information refer to section 'MPC2000D Thermal Overload Protection'.
Stall Time Factor
To cater for stalling on starting particularly when the motor locked rotor characteristic is close to that normally seen
during a start. To achieve adequate protection the thermal characteristic may be switched to a lower value. The
feature is activated by connecting a speed switch between terminals 3 and 4 which enables or disables the stalling
characteristic which is adjustable between the range of 20 and 100% in steps of 1% of the thermal trip times, with a
default setting of 50%.
Overload Reset Method
With the exception of the Thermal Overload Protection all of the MPC2000D protective functions can be disabled.
When set to Auto the Overload trip will be self-reset when the thermal capacity has cooled to below 50% of the
motor capacity without the need for an operator reset. When set to Hand the fault will not reset until an operator reset
is performed but only if the thermal capacity used has reduced to 50%.
