Mode: Open‑Loop
Common Features
Open loop current control
In open loop mode it is possible to control the motor frequency or the motor torque. When the frequency of the motor is controlled (Torque Mode Selector (04.011) = 0) the Post Ramp Reference (02.001) is defined by the ramp system unless the current limits are active. The Post Ramp Reference (02.001) can directly define the output frequency of the drive or this can be modified to compensate for motor slip. If the current limits are active (Current Limit Active (10.009) = 1) the ramp system remains active, but the output of the current controller is added to the ramp output so that the frequency applied to the motor is modified to try and reduce the torque producing current in the motor. For example, if the Post Ramp Reference (02.001) is positive (i.e. motor is running forwards) and the motor is overloaded with a motoring load a positive Torque Producing Current (04.002) is generated that will exceed the Final Current Limit (04.018). This gives a negative error which attempts to reduce the ramp output causing the motor to slow down.
When motor torque is being controlled (Torque Mode Selector (04.011) = 1) The Final Torque Reference (04.003) is converted to a current reference (flux compensation) and the current limits are applied giving the Final Current Reference (04.004). This is used as the reference input to the PI controller that regulates the torque producing current in the motor. The output of the PI controller is the Post Ramp Reference (02.001), and so the torque is controlled by increasing or decreasing the motor frequency. This system gives only moderate dynamic performance. For better torque control in a system without position feedback, closed loop current control should be used.
It is possible to disable the flux compensation by setting Flux Control Compensation Disable (05.028) to 1.
Current Controller Kp Gain (04.013) and Current Controller Ki Gain (04.014) are the proportional and integral gains of the current controller. As already mentioned the current controller either provides current limits or closed-loop torque control by modifying the Post Ramp Reference (02.001). The control loop is also used in its torque mode during supply loss, or when the standard ramp control mode is active and the drive is decelerating, to regulate the flow of current into the drive. Although the default settings have been chosen to give suitable gains for less demanding applications it may be necessary for the user to adjust the performance of the controller. The following is a guide to setting the gains for different applications.
Current limit operation
The current limits will normally operate with an integral term only, particularly below the point where field weakening begins. The proportional term is inherent in the loop. The integral term must be increased enough to counter the effect of the ramp which is still active even in current limit. For example, if the drive is operating at constant frequency and is overloaded the current limit system will try to reduce the output frequency to reduce the load. At the same time the ramp will try to increase the frequency back up to the demand level. If the integral gain is increased too far the first signs of instability will occur when operating around the point where field weakening begins. These oscillations can be reduced by increasing the proportional gain. A system has been included to prevent regulation because of the opposite actions of the ramps and the current limit. This can reduce the actual level that the current limit becomes active by up to 12.5%. This still allows the current to increase up to the current limit set by the user.
However the current limit flag (Current Limit Active (10.009)) could become active up to 12.5% below the current limit depending on the ramp rate being used.
Torque control
Again the controller will normally operate with an integral term only, particularly below the point where field weakening begins. The first signs of instability will appear around rated frequency, and can be reduced by increasing the proportional gain. The controller can be less stable in torque control mode compared to when it is used for current limiting. This is because load helps to stabilise the controller, and under torque control the drive may operate with light load. Under current limit the drive is often under heavy load unless the current limits are set at a low level.
Supply loss and standard ramp
The d.c. link voltage controller becomes active if supply loss detection is enabled and the drive supply is lost or standard ramp is being used (Ramp Mode Select (02.004) > 0) and the motor is regenerating. The d.c. link controller attempts to hold the d.c. link voltage at a fixed level by controlling the flow of current from the drive inverter into its d.c. link capacitors. The system is forced into current control mode and the output of the d.c. voltage controller is fed into the current controller as shown below.
Although it is not usually necessary, the d.c. link voltage controller gain can be adjusted with the Voltage Controller Gain (05.031). However, it may be necessary to adjust the current controller gains to obtain the required performance. If the gains are not suitable it is best to set up the drive in torque control first. Set the gains to a value that does not cause instability around the point at which field weakening occurs. Then revert back to open loop frequency control in standard ramp mode. To test the controller the supply should be removed whilst the motor is running. It is likely that the gains can be increased further if required because the d.c. link voltage controller has a stabilising effect, provided that the drive is not required to operate in torque control mode.
Parameter | 04.001 Current Magnitude | ||
---|---|---|---|
Short description | Shows the instantaneous drive output current | ||
Mode | Open‑Loop | ||
Minimum | −VM_DRIVE_CURRENT | Maximum | VM_DRIVE_CURRENT |
Default | Units | A | |
Type | 32 Bit Volatile | Update Rate | 16ms |
Display Format | Standard | Decimal Places | 2 |
Coding | RO, FI, VM, ND, NC, PT |
Current Magnitude (04.001) is the instantaneous drive output current scaled so that it represents the r.m.s. phase current in Amps under steady state conditions.
Parameter | 04.002 Torque Producing Current | ||
---|---|---|---|
Short description | Shows the instantaneous level of torque producing current | ||
Mode | Open‑Loop | ||
Minimum | −VM_DRIVE_CURRENT | Maximum | VM_DRIVE_CURRENT |
Default | Units | A | |
Type | 32 Bit Volatile | Update Rate | 1ms |
Display Format | Standard | Decimal Places | 2 |
Coding | RO, FI, VM, ND, NC, PT |
Torque Producing Current (04.002) is the instantaneous level of torque producing current scaled so that it represents the r.m.s. level of torque producing current under steady state conditions. Torque Producing Current (04.002) is proportional to the torque produced by the motor provided field weakening is not active. For field weakening operation the Torque Producing Current (04.002) is boosted for a given level of torque to compensate for the reduction in the motor flux. The sign of Torque Producing Current (04.002) is defined in the table below.
The Rated Torque Producing Current for the motor is given by:
ITrated = motor rated power factor (05.010) x motor rated current (05.007).
Sign of Torque Producing Current (04.002) | Sign of frequency | Direction of motor torque |
+ | + | Accelerating |
- | + | Decelerating |
+ | - | Decelerating |
- | - | Accelerating |
Parameter | 04.003 Final Torque Reference | ||
---|---|---|---|
Short description | Shows the final torque reference | ||
Mode | Open‑Loop | ||
Minimum | −VM_TORQUE_CURRENT | Maximum | VM_TORQUE_CURRENT |
Default | Units | % | |
Type | 16 Bit Volatile | Update Rate | 1ms |
Display Format | Standard | Decimal Places | 1 |
Coding | RO, FI, VM, ND, NC, PT |
The Final Torque Reference (04.003) will display the same as Torque Reference (04.008) as a percentage of motor rated torque.
Parameter | 04.004 Final Current Reference | ||
---|---|---|---|
Short description | Shows the final current reference after the current limits | ||
Mode | Open‑Loop | ||
Minimum | −VM_TORQUE_CURRENT | Maximum | VM_TORQUE_CURRENT |
Default | Units | % | |
Type | 16 Bit Volatile | Update Rate | 1ms |
Display Format | Standard | Decimal Places | 1 |
Coding | RO, FI, VM, ND, NC, PT |
The Final Torque Reference (04.003) is converted into the Final Current Reference (04.004) by applying a torque to current conversion and by applying the Final Current Limit (04.018). The torque to current conversion is applied as follows:
|Output Frequency (05.001)| ≤ Motor Rated Frequency (05.006)
Current reference = Final Torque Reference (04.003)
|Output Frequency (05.001)| > Motor Rated Frequency (05.006)
Current reference = Final Torque Reference (04.003) x | Output Frequency (05.001) | / Motor Rated Frequency (05.006)
It is possible to disable the flux compensation by setting Flux Control Compensation Disable (05.028) to 1.
Parameter | 04.005 Motoring Current Limit | ||
---|---|---|---|
Short description | Defines the current limit used when the motor is being accelerated away from standstill | ||
Mode | Open‑Loop | ||
Minimum | −VM_MOTOR1_CURRENT_LIMIT | Maximum | VM_MOTOR1_CURRENT_LIMIT |
Default | 165.0 | Units | % |
Type | 16 Bit User Save | Update Rate | 16ms |
Display Format | Standard | Decimal Places | 1 |
Coding | RW, VM, RA |
The Motoring Current Limit (04.005) limits the current when the motor is being accelerated away from standstill. The Regenerating Current Limit (04.006) limits the current when the motor is being decelerated towards standstill. If the Symmetrical Current Limit (04.007) is below the Motoring Current Limit (04.005) then it is used instead of the Motoring Current Limit (04.005). If the Symmetrical Current Limit (04.007) is below the Regenerating Current Limit (04.006) then it is used instead of the Regenerating Current Limit (04.006).
The maximum possible current limit (VM_MOTOR1_CURRENT_LIMIT [MAX]) varies between drive sizes with default parameters loaded. For some drive sizes the default value may be reduced below the value given by the parameter range limiting.
Parameter | 04.006 Regenerating Current Limit | ||
---|---|---|---|
Short description | Defines the current limit used when the motor is being decelerated towards standstill | ||
Mode | Open‑Loop | ||
Minimum | −VM_MOTOR1_CURRENT_LIMIT | Maximum | VM_MOTOR1_CURRENT_LIMIT |
Default | 165.0 | Units | % |
Type | 16 Bit User Save | Update Rate | 16ms |
Display Format | Standard | Decimal Places | 1 |
Coding | RW, VM, RA |
See Motoring Current Limit (04.005).
Parameter | 04.007 Symmetrical Current Limit | ||
---|---|---|---|
Short description | Defines the symmetrical current limit | ||
Mode | Open‑Loop | ||
Minimum | −VM_MOTOR1_CURRENT_LIMIT | Maximum | VM_MOTOR1_CURRENT_LIMIT |
Default | 165.0 | Units | % |
Type | 16 Bit User Save | Update Rate | 16ms |
Display Format | Standard | Decimal Places | 1 |
Coding | RW, VM, RA |
See Motoring Current Limit (04.005).
Parameter | 04.008 Torque Reference | ||
---|---|---|---|
Short description | Defines the torque reference | ||
Mode | Open‑Loop | ||
Minimum | −VM_USER_CURRENT | Maximum | VM_USER_CURRENT |
Default | 0.0 | Units | % |
Type | 32 Bit User Save | Update Rate | 1ms |
Display Format | Standard | Decimal Places | 1 |
Coding | RW, VM |
See Final Torque Reference (04.003).
Parameter | 04.011 Torque Mode Selector | ||
---|---|---|---|
Short description | Defines the torque mode used by the drive | ||
Mode | Open‑Loop | ||
Minimum | 0 | Maximum | 1 |
Default | 0 | Units | |
Type | 8 Bit User Save | Update Rate | 16ms |
Display Format | Standard | Decimal Places | 0 |
Coding | RW |
If Torque Mode Selector (04.011) = 0 the ramp system defines the Post Ramp Reference (02.001) unless the current limits are active, and so the motor is frequency controlled. If Torque Mode Selector (04.011) = 1 the torque controller defines the Post Ramp Reference (02.001), and so the motor is torque controlled.
Parameter | 04.013 Current Controller Kp Gain | ||
---|---|---|---|
Short description | Defines the current loop controller proportional gain | ||
Mode | Open‑Loop | ||
Minimum | 0.00 | Maximum | 4000.00 |
Default | 20.00 | Units | |
Type | 32 Bit User Save | Update Rate | Background read |
Display Format | Standard | Decimal Places | 2 |
Coding | RW |
Current Controller Kp Gain (04.013) and Current Controller Ki Gain (04.014) are the proportional and integral gains of the current controller.
Refer to Torque and Current control .
Parameter | 04.014 Current Controller Ki Gain | ||
---|---|---|---|
Short description | Defines the current loop controller integral gain | ||
Mode | Open‑Loop | ||
Minimum | 0.000 | Maximum | 600.000 |
Default | 40.000 | Units | |
Type | 32 Bit User Save | Update Rate | Background read |
Display Format | Standard | Decimal Places | 3 |
Coding | RW |
See Current Controller Kp Gain (04.013).
Parameter | 04.015 Motor Thermal Time Constant 1 | ||
---|---|---|---|
Short description | Set to the thermal time constant for the motor | ||
Mode | Open‑Loop | ||
Minimum | 1 | Maximum | 3000 |
Default | 179 | Units | s |
Type | 16 Bit User Save | Update Rate | Background read |
Display Format | Standard | Decimal Places | 0 |
Coding | RW |
A single time constant thermal model is provided that can be used to estimate the motor temperature as a percentage of its maximum allowed temperature. The input to the model is the Current Magnitude (04.001). Throughout the following discussion Motor Rated Current (05.007) is used in the model assuming Select Motor 2 Parameters (11.045) = 0. If Select Motor 2 Parameters (11.045) = 1 then M2 Motor Rated Current (21.007) and M2 Motor Thermal Time Constant 1 (21.016) are used instead.
Percentage Losses
The losses in the motor are calculated as a percentage value, so that under these conditions the Motor Protection Accumulator (04.019) would eventually reach 100%.
Percentage Losses = 100% x [Load Related Losses]
where
Load Related Losses = (I / (K1 x IRated))2
where
I = Current Magnitude (04.001)
IRated = Motor Rated Current (05.007)
The value of K1 defines the continuous allowable motor overload as a proportion of the Motor Rated Current (05.007) before the Motor Protection Accumulator (04.019) reaches 100%. The value of K1 can be used to model reduced cooling at low frequencies and to allow the motor to operate under rated conditions with a small margin to prevent spurious trips. K1 is defined in more detail later.
Motor Protection Accumulator
So far the steady state motor losses have been defined, but the motor model must estimate the temperature within the motor under dynamically changing conditions, and so the Motor Protection Accumulator (04.019) is given by the following equation.
T = Percentage Losses x (1 - e-t/τ1)]
where
T = Motor Protection Accumulator (04.019)
τ1 = Motor Thermal Time Constant 1 (04.015)
Reduced cooling with lower frequency
If Low Frequency Thermal Protection Mode (04.025) = 0 the characteristic is intended for a motor which can operate at rated current over the whole frequency range. Induction motors with this type of characteristic normally have forced cooling. If Low Frequency Thermal Protection Mode (04.025) = 1 the characteristic is intended for motors where the cooling effect of motor fan reduces with reduced motor frequency below half of rated frequency. The maximum value for K1 is 1.05, so that above the knee of the characteristics the motor can operate continuously up to 105% of rated current.
If Motor Rated Current (05.007) > Maximum Heavy Duty Rating (11.032) then K1 is defined as shown below. Two different characteristics are provided, but in both cases the motor performance is limited at lower frequencies and the permissible overload is reduced from 105% to 101%.
Time for Motor Protection Accumulator to reach 100%
The time for the Motor Protection Accumulator (04.019) to change from its initial value to 100% is given by the following equation:
Time to reach 100.0% = -τ1 x ln[(1 - C1) / (C0 - C1)]
C0 represents the conditions that have persisted for long enough for the Motor Protection Accumulator (04.019) to reach a steady state value. If the motor current is I0 then
C0 = [(I0 / (K1 x IRated)]2
C1 represents the conditions that begin at the start of the time being calculated. If the motor current is I1 then
C1 = [(I1 / (K1 x IRated)]2
Example 1: Motor Thermal Time Constant 1 (04.015) = 179s, the initial current is zero, Motor Rated Current (05.007) ≤ Maximum Heavy Duty Rating (11.032) and the new level of current is 1.5 x Motor Rated Current (05.007).
C0 = 0
C1 = [1.5 / (1.05 x 1.0)]2 = 2.041
Time to reach 100.0% = -179 x ln(1 - 1/C1) = -179 x ln(1 - (1 / 2.041)) = 120s
This is the default setting for Open loop and Closed Loop modes allowing an induction motor to run at 150% rated current for 120s from cold.
Motor Protection Accumulator Reset
The initial value in the Motor Protection Accumulator (04.019) at power-up is defined by Motor Protection Accumulator Power-up Value (04.036) as given in the table below.
Motor Protection Accumulator Power-up Value (04.036) | Motor Protection Accumulator (04.019) at power-up |
Power Down | The value is saved at power-down and is used as the initial value at power-up |
Zero | The value is set to zero |
Real Time |
If a real-time clock is present and if Date/Time Selector (06.019) is set up to select the real-time clock then the value saved at power-down is modified to include the effect of the motor thermal protection time constants over the time between power-down and power-up. This modified value is then used as the initial value at power-up. If no real time clock is present and this option is selected then the value saved at power-down is used as the initial value. |
The Motor Protection Accumulator (04.019) is reset under the following conditions:
Motor Protection Accumulator Warning
If Percentage Losses > 100% then eventually the Motor Protection Accumulator (04.019) will reach 100% causing the drive to trip or the current limits to be reduced. If this is the case and Motor Protection Accumulator (04.019) > 75.00% then a Motor Overload alarm indication is given and Motor Overload Alarm (10.017) is set to one.
Parameter | 04.016 Thermal Protection Mode | ||
---|---|---|---|
Short description | Set to the require thermal protection mode | ||
Mode | Open‑Loop | ||
Minimum | 0 (Display: 00) | Maximum | 3 (Display: 11) |
Default | 0 (Display: 00) | Units | |
Type | 8 Bit User Save | Update Rate | Background read |
Display Format | Binary | Decimal Places | 0 |
Coding | RW |
Thermal Protection Mode (04.016) defines the action taken by the drive when Motor Protection Accumulator (04.019) reaches 100% and/or the drive thermal monitoring parameters approach their trip levels. The bits in Thermal Thermal Protection Mode (04.016) are defined as follows:
Bit | Function |
0 | 0 = Motor Too Hot trip is initiated when Motor Protection Accumulator (04.019) reaches 100% 1 = Motor Too Hot trip is disabled and current limiting on motor overload is active as described below |
1 | 0 = Drive thermal monitoring current limiting is disabled 1 = Drive thermal monitoring current limiting is described is active |
Because of the limited number of segments on drives with an LED display, these drives will indicate the parameter value as a decimal value rather than a binary value.
The required current limit is derived from the current limit parameters (Motoring Current Limit (04.005) to Symmetrical Current Limit (04.007) or 21.027 to 21.029) depending on the set-up and conditions. The current limit can be further limited by current limit on motor overload and/or drive temperature monitoring as shown below to give the Final Current Limit (04.018).
Current limiting on motor overload
When the Motor Protection Accumulator (04.019) reaches 100.0% the current limit is limited to (K - 0.05) x 100.0%. This limitation is removed when the Motor Protection Accumulator (04.019) falls below 95.0%.
Drive thermal monitoring current limiting
If any of the drive temperature monitoring parameters (Stack Temperature (07.004) and Auxiliary Temperature (07.005)) are above their trip threshold minus 10°C the one that is closest to its trip threshold is used to modify the current limits as follows:
Final Current Limit (04.018) = Current limit x (Trip threshold - T) / (Trip threshold - 10°C)
where T is the drive temperature monitoring parameter value.
If the Percentage Of Drive Thermal Trip Level (07.036) is above 90% then the final current limit is modified as follows:
Final Current Limit (04.018) = Current limit x (100% - Percentage Of Drive Thermal Trip Level (07.036)) / 10%
If both of the above attempt to reduce the final current limit the lowest calculated value of current limit is used. This system has the effect of reducing the current limit to zero at the point where the drive should be tripped because its thermal monitoring has reached a trip threshold. This is intended to limit the load on the drive to prevent it from tripping when supplying a load that increases with frequency and does not include rapid transients (i.e. a fan).
Parameter | 04.017 Magnetising Current | ||
---|---|---|---|
Short description | Shows the instantaneous level of magnetising current | ||
Mode | Open‑Loop | ||
Minimum | −VM_DRIVE_CURRENT | Maximum | VM_DRIVE_CURRENT |
Default | Units | A | |
Type | 32 Bit Volatile | Update Rate | 1ms |
Display Format | Standard | Decimal Places | 2 |
Coding | RO, FI, VM, ND, NC, PT |
Magnetising Current (04.017) is the instantaneous level of magnetising current scaled so that it represents the r.m.s. level of magnetising current under steady state conditions.
Parameter | 04.018 Final Current Limit | ||
---|---|---|---|
Short description | Shows the final current limit that is applied to the torque producing current | ||
Mode | Open‑Loop | ||
Minimum | −VM_TORQUE_CURRENT | Maximum | VM_TORQUE_CURRENT |
Default | Units | % | |
Type | 16 Bit Volatile | Update Rate | 16ms |
Display Format | Standard | Decimal Places | 1 |
Coding | RO, VM, ND, NC, PT |
Final Current Limit (04.018) is the current limit level that is applied to the torque producing current. See Thermal Protection Mode (04.016).
Parameter | 04.019 Motor Protection Accumulator | ||
---|---|---|---|
Short description | Shows the level of the motor protection accumulator | ||
Mode | Open‑Loop | ||
Minimum | 0.0 | Maximum | 100.0 |
Default | Units | % | |
Type | 16 Bit Power Down Save | Update Rate | Background write |
Display Format | Standard | Decimal Places | 1 |
Coding | RO, ND, NC, PT |
See Motor Thermal Time Constant 1 (04.015).
Parameter | 04.020 Percentage Load | ||
---|---|---|---|
Short description | Shows the level of torque producing current as a percentage of rated torque producing current for the motor | ||
Mode | Open‑Loop | ||
Minimum | −VM_USER_CURRENT | Maximum | VM_USER_CURRENT |
Default | Units | % | |
Type | 16 Bit Volatile | Update Rate | Background write |
Display Format | Standard | Decimal Places | 1 |
Coding | RO, FI, VM, ND, NC, PT |
Percentage Load (04.020) gives the Torque Producing Current (04.002) as a percentage of the rated torque producing current for the motor. Positive values indicate motoring and negative values represent regenerating.
Parameter | 04.024 User Current Maximum Scaling | ||
---|---|---|---|
Short description | Defines the maximum for the torque reference and percentage load parameters | ||
Mode | Open‑Loop | ||
Minimum | −VM_TORQUE_CURRENT_UNIPOLAR | Maximum | VM_TORQUE_CURRENT_UNIPOLAR |
Default | 165.0 | Units | % |
Type | 16 Bit User Save | Update Rate | Background read |
Display Format | Standard | Decimal Places | 1 |
Coding | RW, VM, RA |
User Current Maximum Scaling (04.024) defines the variable maximum/minimums VM_USER_CURRENT which is applied to Percentage Load (04.020). This is useful when routing these parameters to an analogue output as it allows the full scale output value to be defined by the user.
It also defines the maximum value of Torque Reference (04.008) such that when torque is is being set by an analog input the maximum value set here will be requested when the analog input is at maximum.
The maximum value (VM_TORQUE_CURRENT_UNIPOLAR [MAX]) varies between drive sizes with default parameters loaded. For some drive sizes the default value may be reduced below the value given by the parameter range limiting.
Parameter | 04.025 Low Frequency Thermal Protection Mode | ||
---|---|---|---|
Short description | Set to enable low frequency thermal protection mode | ||
Mode | Open‑Loop | ||
Minimum | 0 | Maximum | 1 |
Default | 0 | Units | |
Type | 8 Bit User Save | Update Rate | Background read |
Display Format | Standard | Decimal Places | 0 |
Coding | RW |
See Motor Thermal Time Constant 1 (04.015).
Parameter | 04.026 Percentage Torque | ||
---|---|---|---|
Short description | Displays the torque producing current as a percentage or motor rated current | ||
Mode | Open‑Loop | ||
Minimum | −VM_USER_CURRENT | Maximum | VM_USER_CURRENT |
Default | Units | % | |
Type | 16 Bit Volatile | Update Rate | Background read |
Display Format | Standard | Decimal Places | 1 |
Coding | RO, FI, VM, ND, NC, PT |
Percentage Torque (04.026) gives the Torque Producing Current (04.002) as a percentage of the rated torque producing current for the motor, but with an additional adjustment above rated frequency so that it gives percentage torque. Below rated frequency, Percentage Torque (04.026) = Percentage Load (04.020). Above rated frequency, the Percentage Torque (04.026) is adjusted as follows:
Percentage Torque (04.026) = Percentage Load (04.020) x Motor Rated Frequency (05.006) / Output Frequency (05.001)
Parameter | 04.036 Motor Protection Accumulator Power-up Value | ||
---|---|---|---|
Short description | Defines the initial power-up value of the motor protection accumulator | ||
Mode | Open‑Loop | ||
Minimum | 0 | Maximum | 2 |
Default | 0 | Units | |
Type | 8 Bit User Save | Update Rate | Background write |
Display Format | Standard | Decimal Places | 0 |
Coding | RW, TE |
Value | Text |
0 | Pr.dn |
1 | 0 |
2 | Real t |
See Motor Thermal Time Constant 1 (04.015).
Parameter | 04.041 User Over Current Trip Level | ||
---|---|---|---|
Short description | Defines the trip level for the user over-current trip as a percentage of the drive over current trip level. | ||
Mode | Open‑Loop | ||
Minimum | 0 | Maximum | 100 |
Default | 100 | Units | % |
Type | 8 Bit User Save | Update Rate | Background Read |
Display Format | Standard | Decimal Places | 0 |
Coding | RW, RA |
The User Over-Current Trip protection level in % of Full Scale Current Kc (11.061) which is the full scale current in r.m.s. Amps. The User Over-Current Trip may be used to limit the output current of the drive when supplying a motor with a lower current rating than the drive. If the value of User Over Current Trip Level (04.041) is set at 100%, the user over-current trip is disabled.