Fairford Electronics QFE Series, Manual

Page: 49 / 194

QFE
page 2-25
Electrical Installation
FD8413 issue03_F
2.10.5 Overcurrent Trip Graph
0.01
0.1
1
10
100
1000
1
2 3 4 5 6 7 8 9 10
Fault current ( Motor Current x N )
Seconds
to trip
Overload start point
Delay = 80
Delay = 30
Delay = 10
P35 (or P94)
Default
Delay = 140
‡
(adjustable by P34 (or P93) ‡; default setting: 110%)
‡ Parameter selected through either the primary or secondary group of value parameters
'Current limit', 'Overload level' and 'Overload delay' settings may be adjusted to limit overload
currents in accordance with the trip curves shown here.
For motors with FLC's
lower than the rated current of the QFE the Overload level' may be
adjusted using the following formula:
Overload level = Motor FLC x 1.1 (A)
Notes:
1 The overload monitors one of the phases only and the 'Current Limit' level
is only active during motor starting.
2 It is recommended that the control supply is maintained between starts to
ensure the integrity of the overload, which will reset on it's removal