ABB ACH550-UH User Manual page 130

1-130
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
Parameters
Group 30: Fault Functions
Range
256...9999 s
MOTOR THERM TIME
50...150%
25...150%
.
MOTOR NOM CURR
1...250 Hz
have default values.
0.4 0.6 0.8 1.0
Resolution
1 s
Motor load
equals Temp. rise
100%
1%
P 3007
P 3008
1%
1 Hz
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
ACH550-UH User's Manual
Default
1050 s
63%
P 3006
100%
Output current relative to
9906
MOTOR NOM CURR
150
100 =
127%
50
P 3009
70%
35 Hz
, 3007
MOT LOAD CURVE
S
t
t
Frequency
and 3008