Machine Protection. YASKAWA Varispeed f7

Machine Protection

Machine Protection

This section explains functions for protecting the machine.

‹

Limiting Motor Torque (Torque Limit Function)

The motor torque limit function is enabled with flux vector control and open-loop vector control.

In the open-loop vector control and flux vector control, the user-set value is applied to the torque limit by calculating internally the torque output by the motor. Enable this function if you do not want a torque above a specified amount to be applied to the load, or if you do not want a regeneration value above a specified amount to occur.

„

Related Constants

Constant

Number

Name Description

Setting

Range

Factory

Setting

Change during

Operation

Control Methods

V/f

V/f with

PG

Open

Loop

Vector

Flux

Vector

MEMO

BUS

Register

L7-01

L7-02

L7-03

L7-04

L7-06

L7-07

Forward drive torque limit

Sets the torque limit value as a percentage of the motor rated torque.

Four individual regions can be set.

Reverse drive torque limit Output torque

Positive torque

Forward regenerative torque limit

Reverse

Regenerative state

Regenerative state

No. of motor rotations

Forward

Reverse regenerative torque limit

Negative torque

Integral time setting for torque limit

Set the integral time for the torque limit. When integral control is set for the torque limit, reduce this setting to increase the change in frequency for the torque limit.

Control method selection for torque limit during acceleration and deceleration

Select the control method for the torque limit during acceleration and deceleration.

0: Proportional control (integral control during constant speed)

1: Integral control

Usually, this constant does not need to be set.

For applications in which the torque limit will be reached during acceleration and deceleration, torque control can be given priority by selecting integral control.

When the torque is limited, the acceleration and deceleration times may increase or the motor speed may not agree with the speed reference value.

0 to

300

0 to

300

0 to

300

0 to

300

5 to

10000

0 or 1

200%

200%

200%

200%

No

No

No

No

200 ms No

0 No

No No A

No No A

No No A

No No A

A 4A7H

A 4A8H

A 4A9H

A 4AAH

No No A No 4ACH

No No A No 4C9H

6-

49

6

-50

Multi-function Analog Input ( H3-05, H3-09)

Setting

Value

Function Contents (100%)

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

No No Yes Yes 10

11

12

15

Positive torque limit

Negative torque limit

Regenerative torque limit

Positive/negative torque limit

Motor's rated torque

Motor's rated torque

Motor's rated torque

Motor's rated torque

No

No

No

No

No

No

Yes

Yes

Yes

Yes

Yes Yes

Note The forward torque limit is the limit value when the analog input signal generates forward torque. This torque limit setting is enabled even when the analog input signal generates forward torque while the motor is operating (regeneration).

„

Setting the Torque Limit in Constants

Using L7-01 to L7-04, you can set individually four torque limits in the following directions: Forward drive, reverse drive, forward regeneration, and reverse regeneration.

„

Set the Torque Limit Value Using an Analog Input

You can change the analog input level torque limit value by setting the torque limit in multi-function analog input terminals A2 and A3 .

The analog input terminal signal level is factory-set as follows:

Multi-function analog input terminal A2: 4 to 20 mA

Multi-function analog input terminal A3: 0 to 10

The following diagram shows the relationship between the torque limits.

Output torque

Positive

Positive/negative torque limits

Forward torque limit

Regenerative torque limit

Reverse operation

Negative torque limit

Negative

Fig 6.36 Torque Limit by Analog Input

No. of motor rotations

Forward operation

Regenerative torque limit

Positive/negative torque limits

Machine Protection

„

Setting Torque Limits Using Constants and an Analog Input

The following block diagram shows the relationship between torque limit using constants and torque limit using an analog input.

The lowest torque limit set from among the following is enabled: Torque limit using constants, torque limit using an analog input, 150% of Inverter rating (when set to CT), or 120% of Inverter rating (when set to VT) set in C6-01.

Multi-function analog input

Terminal or A3

(set value = 10)

Constants

Negative torque limit

(set value = 11)

Regenerative torque limit

(set value = 12)

Positive/negative torque limit

(set value = 15)

Positive forward drive torque

Reverse drive reverse torque

Reverse positive regenerative torque

Forward negative regenerative torque

Forward torque limit

(L7-01)

Reverse torque limit

(L7-02)

Forward regenerative torque limit (L7-03)

Reverse regenerative torque limit (L7-04)

150% (when set to CT) or 120% (when set to VT) of Inverter rated current

Min: Minimum value priority circuit

Forward torque limit

Reverse torque limit

Forward regenerative torque limit

Reverse regenerative torque limit

Fig 6.37 Torque Limit Using Constants and an Analog Input

„

Selecting the Control Method for Torque Limit during Acceleration and Deceleration

(SPEC: E or later only)

L7-07 is used to select the control method for the torque limit during acceleration and deceleration. The selections are proportional control and integral control. For applications, in which the torque limit will be reached during acceleration and deceleration, torque control can be given priority by selecting integral control. To increase the change in frequency for the torque limit when integral control is selected, decrease the value set for L7-06 (Integral Time Setting for Torque Limit).

„

Setting Precautions

•

•

•

When the torque limit function is operating, control and compensation of the motor speed is disabled because torque control is given priority. Therefore, the acceleration and deceleration times may increase or the number of motor rotations may decrease.

When using the torque limit to raise and lower loads, do not carelessly lower the torque limit value, as this may result in the motor falling or slipping.

Torque limits using an analog input are the upper limit value (during 10 V or 20 mA input) of 100% of the motor rated torque. To make the torque limit value during 10 V or 20 mA input 150% of the rated torque, set the input terminal gain to 150.0 (%). Adjust the gain for multi-function analog input terminal A2 using

H3-10 and for multi-function analog input terminal A3 using H3-06.

•

•

The torque limit accuracy is ±5% at the output frequency of 10 Hz or above. When output frequency is less than 10 Hz, accuracy is lowered.

When the torque is limited while L7-07 is set to 1 (integral control), the acceleration and deceleration times may increase or the motor speed may not agree with the speed reference value.

6-

51

6

-52

‹

Preventing Motor Stalling During Operation

Stall prevention during operation prevents the motor from stalling by automatically lowering the Inverter's output frequency when a transient overload occurs while the motor is operating at a constant speed.

Stall prevention during operation is enabled only during V/f control. If the Inverter output current continues to exceed the setting in constant L3-06 for 100 ms or longer, the motor speed is reduced. Set whether to enable or disable deceleration time using constant L3-05. Set the deceleration time using C1-02 (Acceleration time 1) or

C1-04 (Acceleration Time 2).

If the Inverter output current reaches the set value in L3-06 - 2% (Inverter Rated Output Current), the motor will accelerate again at the frequency set or the acceleration time set.

„

Related Constants

Constant

Number

Name Description

Setting

Range

Factory

Setting

Change during

Operation

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

MEMO

BUS

Register

L3-05

Stall prevention selection during running

0: Disabled (Runs as set. With a heavy load, the motor may stall.)

1: Deceleration time 1 (the deceleration time for the stall prevention function is C1-

02.)

2: Deceleration time 2 (the deceleration time for the stall prevention function is C1-

04.)

0 to 2 1 No A A No No 493H

L3-06

Stall prevention level during running

Effective when L3-05 is 1 or 2.

Set as a percentage of the

Inverter rated output current.

Usually setting is not necessary.

The factory setting reduces the set values when the motor stalls.

30 to

200

120%

*

150%

*

* C6-01= 1: 120 %, C6-01= 0: 150 %

No A A No No 494H

Machine Protection

‹

Changing Stall Prevention Level during Operation Using an Analog Input

If you set H3-09 (Multi-function Analog Input Terminal A2 Function Selection) or H3-05 (Multi-function

Analog Input Terminal A3 Function Selection) to 8 (stall prevention level during run), you can change the stall level during operation by setting H3-10 [Gain (Terminal A2)] and H3-11 [Bias (Terminal A2)] or H3-06 [Gain (Terminal A3)] and H3-07 [Bias (Terminal A3)

The stall prevention level during operation enabled is the multi-function analog input terminal A2 or A3 input level or the set value in constant L3-06, whichever is the smaller.

Stall prevention level during operation

Multi-function analog input terminal A2, A3 input level

(4 mA) (8.8 mA) (20 mA)

Fig 6.38 Stall Prevention Level during Operation Using an Analog Input

If the motor capacity is smaller than the Inverter capacity or the motor stalls when operating at the factory settings, lower the stall prevention level during operation.

INFO

‹

Using Frequency Detection

Set these constants when outputting one of the frequency agree or frequency detection signals from a multifunction output. When using flux vector control, the motor speed is detected.

Constant

Number

Name Description

Setting

Range

Factory

Setting

Change during

Operation

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

MEMO

BUS

Register

L4-01

Speed agreement detection level

L4-02

Speed agreement detection width

Effective when “Desired frequency (ref/setting) agree 1,”

“Frequency detection 1,” or

“Frequency detection 2" is set for a multi-function output.

Frequencies to be detected are set in Hz units.

Effective when “Frequency

(speed) agree 1,” “Desired frequency (speed) agree 1,” or

“Frequency (FOUT) detection

1,” Frequency (FOUT) detection

2 is set for a multi-function output.

Sets the frequency detection width in Hz units.

0.0 to

400.0

*1

0.0 to

300.0

*2

0.0 to

20.0

0.0 Hz

2.0 Hz

No

No

A

A

A

A

A

A

A 499H

A 49AH

6-

53

6

-54

Constant

Number

Name Description

Setting

Range

Factory

Setting

Change during

Operation

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

MEMO

BUS

Register

L4-03

L4-04

Speed agreement detection level (+/

-)

Effective when “Desired frequency (speed) agree 2,” “Frequency (FOUT) detection 3,” or

“Frequency (FOUT) detection

4" is set for a multi-function output.

Frequency that should be detected is set in Hz units.

Speed agreement detection width (+/

-)

Effective when “Frequency

(speed) agree 2,” “Desired frequency (speed) agree 2,” Frequency (FOUT) detection 3 or

“Frequency detection 4" is set for a multi-function output.

Frequency detection width is set in Hz units.

-400.0 to

+400.0

*3

-300.0 to

+300.0

*4

0.0 to

20.0

0.0 Hz

2.0 Hz

No

No

A

A

A

A

A

A

A 49BH

A 49CH

* 1. When C6-01 = 0, the upper limit is 150.0.

* 2. When C6-01 = 1, the upper limit is 400.0.

* 3. When C6-01 = 0, -150.0 to +150.0.

* 4. When C6-01 = 1, -400.0 to +400.0

„

Constants and Output Signals

User Constant Number

L4-01

Name

Speed agree detection level

L4-02

L4-03

L4-04

Speed agree detection width

Speed agree detection level (+/-)

Speed agree detection width (+/-)

Function

Fref/Set Agree 1

Frequency Detection 1

Frequency Detection 2

Fref/Fout Agree 1

Fref/Set Agree 1

Frequency Detection 1

Frequency Detection 2

Fref/Set Agree 2

Frequency Detection 3

Frequency Detection 4

Fref/Fout Agree 2

Fref/Set Agree 2

Frequency Detection 3

Frequency Detection 4

Set the corresponding setting in the multi-function output (H2-01 to H2-03) to output the desired Fref/Fout

Agree signal, Fref/Set Agree signal, or Frequency Detection signal.

Function

Fref/Fout Agree 1

Fref/Set Agree 1

Frequency Detection 1

Frequency Detection 2

Fref/Fout Agree 2

Fref/Set Agree 2

Frequency Detection 3

Frequency Detection 4

Setting

2

3

13

14

4

5

15

16

Machine Protection

Timing Chart for Frequency Detection Operation

Related constant

L4-01: Speed Agree Level

L4-02: Speed Agree Width

Fref/Fout Agree 1

L4-03: Speed Agree Level +/ −

L4-04: Speed Agree Width +/ −

Fref/Fout Agree 2

Frequency reference

Fref/Fout

Agree

Output frequency or motor speed

L4-02

Frequency reference

Output frequency or motor speed

L4-04

L4-02

Fref/Fout Agree 1 OFF ON

(Multi-function output setting = 2)

Fref/Set Agree 1

(ON at the following conditions during frequency agree)

Fref/Fout Agree 2 OFF ON

(Multi-function output setting = 13)

Fref/Set Agree 2

(ON at the following conditions during frequency agree)

Fref/Set

Agree

Output frequency or motor speed

L4-01

Fref/Set Agree 1 OFF ON

(Multi-function output setting = 3)

Frequency (FOUT) Detection 1

(L4-01 > | Output frequency | )

L4-02

L4-02

L4-01

L4-02

L4-01

Output frequency or motor speed

L4-01

Frequency

Detection

Freq. Detection 1

ON OFF

(Multi-function output setting = 4)

Frequency (FOUT) Detection 2

(L4-01 < | Output frequency | )

L4-02

L4-02

L4-01

Output frequency or motor speed

Freq. Detection 2

OFF ON

(Multi-function output setting = 5)

L4-01

L4-02

Output frequency or motor speed

Fref/Set Agree 2 OFF ON

(Multi-function output setting = 14)

Frequency (FOUT) Detection 3

(L4-03 > Output frequency)

Output frequency or motor speed

Freq. Detection 3

ON OFF

(Multi-function output setting = 15)

Frequency (FOUT) Detection 4

(L4-01 < Output frequency)

Output frequency or motor speed

Freq. Detection 4 OFF ON

(Multi-function output setting = 16)

L4-04

L4-03

L4-04

L4-03

L4-04

L4-03

6-

55

6

-56

‹

Detecting Motor Torque

If an excessive load is placed on the machinery (overtorque) or the load is suddenly lightened (undertorque), you can output an alarm signal to multi-function output terminal M1-M2, P1-PC, or P2-PC.

To use the overtorque/undertorque detection function, set B, 17, 18, 19 (overtorque/undertorque detection NO/

NC) in one of the following constants: H2-01 to H2-03 (multi-function output terminals M1-M2, P1-PC, and

P2-PC function selection).

The overtorque/undertorque detection level is the current level (Inverter rated output current 100%) in V/f control, and the motor torque (motor rated torque 100%) in vector control.

„

Related Constants

Constant

Number

L6-01

L6-02

Name Description

Setting

Range

Factory

Setting

Change during

Operation

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

MEMO

BUS

Register

Torque detection selection

1

0: Overtorque/undertorque detection disabled.

1: Overtorque detection only with speed agreement; operation continues after overtorque (warning).

2: Overtorque detected continuously during operation; operation continues after overtorque

(warning).

3: Overtorque detection only with speed agreement; output stopped upon detection (protected operation).

4: Overtorque detected continuously during operation; output stopped upon detection (protected operation).

5: Undertorque detection only with speed agreement; operation continues after overtorque (warning).

6: Undertorque detected continuously during operation; operation continues after overtorque

(warning).

7: Undertorque detection only with speed agreement; output stopped upon detection (protected operation).

8: Undertorque detected continuously during operation; output stopped upon detection (protected operation).

0 to 8 0

Torque detection level 1

Open loop vector control: Motor rated torque is set as 100%.

V/f control: Inverter rated current is set as 100%.

0 to 300 150%

No

No

A

A

A

A

A

A

A 4A1H

A 4A2H

Machine Protection

Constant

Number

Name Description

L6-03

L6-04

L6-05

L6-06

Torque detection time 1

Sets the overtorque/undertorque detection time in 1-second units.

Torque detection selection

2

Torque detection level 2

Output of torque detection 1 is enabled by setting B or 17 for

H2†† and output of torque detection 1 is enabled by setting

18 or 18 for H2†† .

Torque detection time 2

Setting

Range

Factory

Setting

Change during

Operation

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

MEMO

BUS

Register

0.0 to

10.0

0.1 s No A A A A 4A3H

0 to 8

0 to

300

0.0 to

10.0

0

150%

0.1 s

No

No

No

A

A

A

A

A

A

A

A

A

A 4A4H

A 4A5H

A 4A6H

Multi-function Output (H2-01 to H2-03)

Setting

Value

B

17

18

19

Function

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

Yes Yes Yes Yes

Overtorque/undertorque detection 1 NO (NO contact: Overtorque/undertorque detection at ON)

Overtorque/undertorque detection 1 NC (NC Contact: Overtorque/undertorque detection at OFF)

Overtorque/undertorque detection 2 NO (NO Contact: Overtorque/undertorque detection at ON)

Overtorque/undertorque detection 2 NC (NC Contact: Overtorque/undertorque detection at OFF)

Yes Yes Yes Yes

Yes Yes Yes Yes

Yes Yes Yes Yes

6-

57

6

-58

„

L6-01 and L6-04 Set Values and LED Indications

The relationship between alarms displayed by the Digital Operator when overtorque or undertorque is detected, and the set values in L6-01 and L6-04, is shown in the following table.

Set

Value

0

Function

LED Indications

Overtorque/

Undertorque

Detection 1

Overtorque/

Undertorque

Detection 2

-

1

2

3

4

5

6

7

8

Overtorque/undertorque detection disabled.

Overtorque detection only with speed matching; operation continues after overtorque (warning).

Overtorque detected continuously during operation; operation continues after overtorque (warning).

Overtorque detection only with speed matching; output stopped upon detection (protected operation).

Overtorque detected continuously during operation; output stopped upon detection (protected operation).

Undertorque detection only with speed matching; operation continues after overtorque (warning).

Undertorque detected continuously during operation; operation continues after overtorque (warning).

Undertorque detection only with speed matching; output stopped upon detection (protected operation).

Undertorque detected continuously during operation; output stopped upon detection (protected operation).

OL3 flashes

OL3 flashes

OL3 lit

OL3 lit

UL3 flashes

UL3 flashes

UL3 lit

UL3 lit

OL4 flashes

OL4 flashes

OL4 lit

OL4 lit

UL4 flashes

UL4 flashes

UL4 lit

UL4 lit

„

Setting Example

The following diagram shows the time chart for overtorque and undertorque detection.

• Overtorque Detection

Motor current (output torque)

* *

L6-02 or L6-05

Overtorque detection 1 NO or overtorque detection 2 NO

L6-03 or

L6-06

L6-03 or

L6-06

ON ON

* Overtorque detection disabled band is approximately 10% of the Inverter rated output

current (or motor rated torque).

Machine Protection

• Undertorque Detection

Motor current (output torque)

L6-02 or L6-05

*

Undertorque detection 1 NO or Undertorque detection 2 NO

L6-03 or

L6-06

L6-03 or

L6-06 ON ON

The undertorque detection disabled margin is approximately 10% of the Inverter rated output

current (or motor rated torque)

‹

Changing Overtorque and Undertorque Detection Levels Using an Analog Input

If you set constant H3-09 (Multi-function Analog Input Terminal A2 Function Selection) or H3-05 (Multi-

(Multi-function Analog Input Terminal A3 Function Selection) to 7 (overtorque/undertorque detection level), you can change the overtorque/undertorque detection level.

If you change the overtorque/undertorque detection level using the multi-function analog input, only overtorque/undertorque detection level 1 will be enabled.

The following diagram shows the overtorque/undertorque detection level using an analog input.

Detection level

Multi-function analog input terminal A2, A3 input level

(4 mA) (20 mA)

Fig 6.39 Overtorque/Undertorque Detection Level Using an Analog Input

Multi-Function Analog Input ( H3-05, H3-09)

Setting

Value

7

Function Contents (100%)

Overtorque/undertorque detection level

Motor rated torque for vector control

Inverter rated output current for V/f control

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

Yes Yes Yes Yes

6-

59

6

-60

‹

Motor Overload Protection

You can protect the motor from overload using the Inverter's built-in electronic thermal overload relay.

„

Related Constants

Constant

Number

Name Description

Setting

Range

Factory

Setting

Change during

Operation

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

E2-01

E4-01

L1-01

L1-02

Motor rated current

Motor 2 rated current

Motor protection selection

Motor protection time constant

Sets the motor rated current in 1

A units.

These set values will become the reference values for motor protection, torque limits and torque control.

This constant is automatically set during autotuning.

Sets the motor rated current in 1

A units.

These set values will become the reference values for motor protection, torque limits and torque control.

This constant is automatically set during autotuning.

Sets whether the motor overload function is enabled or disabled at electric thermal overload relay.

0: Disabled

1: General-purpose motor protection

2: Inverter motor protection

3: Vector motor protection

In some applications when the

Inverter power supply is turned off, the thermal value is reset, so even if this constant is set to

1, protection may not be effective.

When several motors are connected to one Inverter, set to 0 and ensure that each motor is installed with a protection device.

Sets the electric thermal detection time in seconds units.

Usually setting is not necessary.

The factory setting is 150% overload for one minute.

When the motor's overload resistance is known, also set the overload resistance protection time for when the motor is hot started.

0.32 to

6.40

*2

0.32

to 6.40

*2

0 to 3

0.1 to

5.0

1.90 A

*1

1.90 A

*1

1

1.0 min

No

No

No

No

Q

A

Q

A

Q

A

Q

A

Q

A

Q

A

Q

A

Q

A

* 1. The factory settings depend on the Inverter capacity. The values for a 200 V Class Inverter of 0.4 kW are given.

* 2. The setting range is 10% to 200% of the Inverter's rated output current. The value for a 200 V Class Inverter of 0.4 kW is given.

MEMO

BUS

Register

30EH

321H

480H

481H

Machine Protection

Multi-Function Outputs (H2-01 to H2-03)

Setting

Value

Function

1F

Motor overload (OL1, including OH3) pre-alarm (ON: 90% or more of the detection level)

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

Yes Yes Yes Yes

„

Setting Motor Rated Current

Set the rated current value on the motor nameplate in constants E2-01 (for motor 1) and E4-01 (for motor 2).

This set value is the electronic thermal base current.

„

Setting Motor Overload Protection Characteristics

Set the overload protection function in L1-01 according to the applicable motor.

The induction motor's cooling abilities differ according to the speed control range. Consequently, you must select the electronic thermal protection characteristics to match the applicable motor's tolerance load characteristics.

The following table shows the motor type and tolerance load characteristics.

L1-01

Set

Value

Motor Type Tolerance Load Characteristics Cooling Ability

Electronic Thermal

Operation (at 100%

Motor Load)

1

General-purpose motor (standard motor)

Short time 60 s.

Rated rotation speed

= 100% speed

Continuous

Frame number

Max. speed of 200

LJ min.

Frame number Max. speed of 160 MJ to 160 LJ min.

Frame number Max. speed of 132 MJ

Use this motor for operations using a commercial power supply. This motor construction yields best cooling effect when operating at 50/

60 Hz.

When operating continuously at 50/60 Hz or less, motor overload detection

(OL1) is detected. The

Inverter outputs the error contact, and the motor coasts to a stop.

Rotation speed (%)

2

Inverter motor

(constant torque)

(1:10)

Short time 60

Rated rotation speed

= 100% speed

Continuous

Frame number Max. speed of 200 LJ min.

Frame number Max. speed of 160 MJ to 180 LJ

Frame number Max. speed of 132 MJ

This motor yields a cooling effect even when operating at low speeds (approx.

6 Hz).

Operates continuously at 6 to 50/60 Hz.

Rotation speed (%)

6-

61

6

-62

L1-01

Set

Value

Motor Type Tolerance Load Characteristics

Short time 60 s.

Rated rotation speed

= 100% speed

Cooling Ability

3

Vector motor

(1:100)

Electronic Thermal

Operation (at 100%

Motor Load)

Continuous

Frame number

Max. speed of

200 LJ min.

Frame number Max. speed of 160 MJ to 180 LJ

Frame number Max. speed of 132 MJ

This motor yields a cooling effect even when operating at extremely low speeds

(approx. 0.6 Hz).

Operates continuously at

0.6 to 60 Hz.

Rotation speed (%)

‹

Setting Motor Protection Operation Time

Set the motor protection operation time in L1-02.

If, after operating the motor continuously at the rated current, a 150% overload is experienced, set the (hot start) electronic thermal protection operation time. The factory setting is resistance to 150% for 60 seconds.

The following diagram shows an example of the characteristics of the electronic thermal protection operation time (L1-02 = 1.0 min., operation at 60 Hz, general-purpose motor characteristics, when L1-01 is set to 1)

Operating time (min.)

Cold start

Hot start

Motor current (%)

E2-01 is set to 100%

Fig 6.40 Motor Protection Operation Time

„

Setting Precautions

• If multiple motors are connected to one Inverter, set constant L1-01 to 0 (disabled). To protect the motor, install a thermal relay in the motor power cable, and perform overload protection on each motor.

• With applications where the power supply is often turned ON and OFF, there is a risk that the circuit cannot be protected even if this constant has been set to 1 (enabled), because the thermal value will be reset.

• To detect overloads in good time, set the set value in constant L1-02 to a low setting.

• When using a general-purpose motor (standard motor), the cooling ability will be lowered by f 1/4 (frequency). Consequently, the frequency may cause motor overload protection (OL1) to occur, even below the rated current. If operating using the rated current at a low frequency, use a special motor.

Machine Protection

„

Setting the Motor Overload Pre-Alarm

If the motor overload protection function is enabled (i.e., L1-01 is set to other than 0) and you set H2-01 to

H2-03 (multi-function output terminals M1-M2, P1-PC, and P2-PC function selection) to 1F (motor overload

OL1 pre-alarm), the motor overload pre-alarm will be enabled. If the electronic thermal value reaches minimum 90% of the overload detection level, the output terminal that has been set will be turned ON.

‹

Motor Overheating Protection Using PTC Thermistor Inputs

Perform motor overheating protection using the thermistor temperature resistance characteristics of the PTC

(Positive Temperature Coefficient) built into the windings of each motor phase.

„

Related Constants

Constant

Number

Name Description

Setting

Range

Factory

Setting

Change during

Operation

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

MEMO

BUS

Register

L1-03

L1-04

L1-05

Alarm operation selection during motor overheating

Set Multi-function input terminal

A3 (H3-05)

or A2 (H3-09) to E and select the operation when the input motor temperature (thermistor) input exceeds the alarm detection level [1.17 V

(±5%)].

0: Decelerate to stop

1: Coast to stop

2: Emergency stop using the deceleration time in C1-09.

3: Continue operation (H3 on the Operator flashes).

Motor overheating operation selection

Set Multi-function input terminal A3 (H3-05) or A2 (H3-09) to E and select the operation when the motor temperature

(thermistor) input exceeds the operation detection level [2.34V

(±5%)].

0: Decelerate to stop

1: Coast to stop

2: Emergency stop using the deceleration time in C1-09.

Motor temperature input filter time constant

Set Multi-function input terminal A3 (H3-05) or A2 (H3-09) to E and set the primary delay time constant for motor temperature (thermistor) inputs in seconds.

0 to 3

0 to 2

0.00 to

10.00

3

1

0.20 s

No

No

No

A

A

A

A

A

A

A

A

A

A

A

A

482H

483H

484H

6-

63

6

-64

„

PTC Thermistor Characteristics

The following diagram shows the characteristics of the PTC thermistor temperature to the resistance value.

Resistance (ohms)

Class F

150

°

C

Class H

180

°

C

1330

Tr: Temperature threshold value

550

Temperature

Tr

Tr 5 Tr Tr+5

Fig 6.41 PTC Thermistor Temperature-Resistance Value Characteristics

„

Operation during Motor Overheating

Set the operation if the motor overheats in constants L1-03 and L1-04. Set the motor temperature input filter time constant in L1-05. If the motor overheats, the OH3 and OH4 error codes will be displayed on the Digital

Operator.

Error Codes If the Motor Overheats

Error Code

OH3

OH4

Details

Inverter stops or continues to operate, according to the setting in L1-03.

Inverter stops according to the setting in L1-04.

By setting H3-09 (Multi-function Analog Input Terminal A2 Function Selection) or H3-05 (Multi-function

Analog Input Terminal A3 Function Selection) to E (Motor temperature input), you can detect alarm OH3 or OH4 using the PTC temperature-resistance characteristics, and protect the motor. The terminal connections are shown in the following diagram. Set H3-08 〔 Signal level selection (terminal A2) 〕 (H3-04 when A3 is used) to 0 (0 to + 10 V).

Inverter

Multi-function contact input

Multi-function contact output

Fault contact output

Branch resistance

18 k Ω

PTC thermistor

A2, A3

(0-10 V) *

Multi-function

PHC output

* When using terminal A2, set DIP switch S1-2 to OFF (0 to 10 V).

Fig 6.42 Mutual Connections During Motor Overheating Protection

Machine Protection

‹

Limiting Motor Rotation Direction

If you set motor reverse rotation prohibited, a Reverse Run Command will not be accepted even if it is input.

Use this setting for applications in which reverse motor rotation can cause problems (e.g., fans, pumps, etc.)

„

Related Constants

Constant

Number

Name Description b1-04

Prohibition of reverse operation

0: Reverse enabled

1: Reverse disabled

Setting

Range

Factory

Setting

Change during

Operation

V/f

Control Methods

V/f with

PG

Open

Loop

Vector

Flux

Vector

MEMO

BUS

Register

0 or 1 0 No A A A A 183H

6-

65