ABB DriveIT ACH550-UH - Page 97

ACH550-UH User’s Manual 97
Start-Up
3006 MOT THERM TIME 256…9999 s 1 1050 s
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:
MOTOR THERM TIME equals
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 50…150% 1 100%
Sets the maximum allowable operating load of the motor.
• When set to 100%, the maximum allowable load is equal to the
value of Start-up Data parameter 9906
MOTOR NOM CURRENT.
• Adjust the load curve level if the ambient temperature differs from
nominal.
3008 ZERO SPEED LOAD 25…150% 1 70%
Sets the maximum allowable current at zero speed.
• Value is relative to 9906
MOTOR NOM CURR.
3009 BREAK POINT FREQ 1…250 Hz 1 35 Hz
Sets the break point frequency for the motor load curve.
Example: Thermal protection trip
times when parameters 3006
MOT THERM TIME, 3007 MOT
LOAD CURVE and 3008 ZERO
SPEED LOAD have default
values.
Group 30: Fault Functions
Code Description Range Resolution Default S
Temp. Rise
100%
63%
t
t
}
P 3006
Motor load
Frequency
Output current (%) relative
to 9906 MOTOR NOM CURR
150
100
50
P 3007
P 3008
P 3009
60 s
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
0 0.2 0.4 0.8 1.0 1.2
I
O
/I
N
f
O
/f
BRK
90 s
300 s
600 s
0.6
180 s
A
∞
I
O
= Output current
I
N
= Nominal motor current
f
O
= Output frequency
f
BRK
= Break point frequency
A = Trip time