ABB ACQ550-x1-06A6-2 User Manual page 125

ACQ550-U1 User's Manual
Code Description
3006 MOT THERM TIME
Sets the motor thermal time constant for the motor temperature
model.
• This is the time required for the motor to reach 63% of the final
temperature with steady load.
• For thermal protection according to UL requirements for NEMA
class motors, use the rule of thumb:
35 times t6, where t6 (in seconds) is specified by the motor
manufacturer as the time that the motor can safely operate at six
times its rated current.
• The thermal time for a Class 10 trip curve is 350 s, for a Class
20 trip curve 700 s, and for a Class 30 trip curve 1050 s.
3007 MOT LOAD CURVE
Sets the maximum allowable operating load of the motor.
• With the default value 100%, motor overload protection is functioning
when the constant current exceeds 127% of the parameter 9906
MOTOR NOM CURR value.
• The default overloadability is at the same level as what motor
manufacturers typically allow below 30 °C (86 °F) ambient
temperature and below 1000 m (3300 ft) altitude. When the ambient
temperature exceeds 30 °C (86 °F) or the installation altitude is over
1000 m (3300 ft), decrease the parameter 3007 value according to
the motor manufacturer's recommendation.
Example: If the constant protection level needs to be 115% of
the motor nominal current, set parameter 3007 value to 91%
(= 115/127·100%).
3008 ZERO SPEED LOAD
Sets the maximum allowable current at zero speed.
• Value is relative to 9906
3009 BREAK POINT FREQ
Sets the break point frequency for the motor load curve.
Example: Thermal protection trip times when parameters 3006
ZERO SPEED LOAD
I /I
O N
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0 0.2
MOTOR THERM TIME
.
MOTOR NOM CURR
have default values.
0.4 0.6 0.8 1.0
Motor load
Temp. rise
100%
equals
P 3007
P 3008
MOT THERM TIME
A
60 s
I = Output current
O
90 s
I = Nominal motor current
N
f = Output frequency
O
180 s 180 s
f = Break point frequency
BRK
A = Trip time
300 s
600 s

f /f
O BRK
1.2
63%
P 3006
Output current relative to
9906
MOTOR NOM CURR
150
100 =
127%
50
P 3009
, 3007
MOT LOAD CURVE
125
t
t
Frequency
and 3008
Parameters