ACH550-UH User’s Manual
97
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