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K8AC-H

15

Measurement Monitor Value Display Ranges and Functions

Other than measuring the heater current, the K8AC-H can measure the power supply voltage, maximum/minimum current, maximum/minimum 
voltage, and other values. The measurement data can be monitored from a host using RS-485 communications. The measurement monitor value 
names, display ranges, and functions are given in the following table. 

*

Each measurement value can be individually reset. Refer to the 

K8AC-H Digital Heater Element Burnout Detector User’s Manual 

(Cat. No. N132) 

for operating procedures. 

Modes

Groups of setting items are called “modes.” The K8AC-H has five modes.

Note:

If more than five minutes elapses with no operations performed in the Protection Settings Mode, Adjust Mode, or Set Mode, the status will 

return automatically to the processing value display. If this occurs while settings are in progress, it may cause unintended operations in the 

processing value display. Be careful not to allow this to happen.

Settings Data Notation

The letters of the alphabet in settings data are displayed as shown below.

Measurement monitor 

value name

Display char-

acters

Display range

Unit

Function

Power supply voltage

sce

0085 to 0264

V

This is the measurement value of the K8AC-H power supply voltage. When the voltage 
fluctuation compensation function is enabled, the heater burnout determination based on 
this voltage is automatically compensated.

Heater 1 maximum current 

*

max1

0100 to 2300

A

These hold the maximum and minimum values for each processing value.

The maximum and minimum heater currents after the power is turned ON or after a 
maximum or minimum reset are displayed.

The values are not saved when power is interrupted.

The current values are not refreshed when startup lock is in effect and when the gate 
input is enabled but the gate input is OFF.

Measurement values for power supply voltages are always refreshed.

Heater 1 minimum current 

*

min1

0100 to 2300

A

Heater 2 maximum current 

*

max2

0100 to 2300

A

Heater 2 minimum current 

*

min2

0100 to 2300

A

Maximum power supply 
voltage 

*

maxs

0085 to 0264

V

Minimum power supply 
voltage 

*

mins

0085 to 0264

V

Number of alarm outputs

acnt

0000 to 9999

Outputs

This value counts the total number of alarms output for heater burnout, SSR open and 
short circuits, and heater layer shorts.

The count is refreshed each time an alarm is output, and it is saved in non-volatile 
memory.

The value is saved when power is interrupted.

The number of outputs is not counted for the test function.

After counting to 9999, the value is held at 9999 and any further alarms are not 
counted. To return the count to 0, perform a reset.

Processing value for alarm 
output

memo

0100 to 2300

A

This holds the CT1 or CT2 processing value when a heater burnout alarm is output.

This is the most recent processing value, and it is refreshed each time a heater 
burnout alarm occurs.

The value is not saved when power is interrupted.

Run time

otim

0000 to 9999

× 

10h

This is the total run time value from when power is turned ON or the processing value is 
reset until an alarm occurs.

The total time is recorded in non-volatile memory approximately once per hour. If 
power is interrupted within the hour, however, the data since the beginning of the hour 
is lost and the total starts over from when the time was last saved.

The total is stopped during heater burnout alarm output. When the alarm is cleared, 
the total resumes from the time just before the alarm occurred.

Heater 1 input shift display 
current

isc1

999 to 999

digit

This is the shift value for displaying the CT1 heater current measurement set in 
measurement parameter CT1.

The value is saved when power is interrupted.

Heater 2 input shift display 
current

isc2

999 to 999

digit

This is the shift value for displaying the CT2 heater current measurement set in 
measurement parameter CT2.

The value is saved when power is interrupted.

Mode

Function

Alarm operation

Run Mode

This is the normal operating mode, used for receiving inputs, executing heater burnout outputs, etc.
Operation goes into Run Mode immediately after power is turned ON.

Executed

Adjust Mode

This mode is used to change comparatively frequently set parameters, such as alarm value settings. 
This also the mode for entering the password to move to the Set Mode.

Stopped

Set Mode

This mode is used to make the initial settings for the various functions.

Stopped

Protection Settings 
Mode

This mode is used to make settings to prevent unintended key operations. The protected modes are not displayed, 
preventing changes to set values.

Stopped

Test Mode

This mode is used to simulate inputs with key operations to test alarm outputs.

Executed

Gate Mode

This mode sets the gate current value that stops an alarm or detection.

Executed

A B C D E F G H

I

J

K

L M N O P Q R S T U V W X Y Z

a b c d e f g h i j k l m n o p q r s t u V w x y z

Summary of Contents for K8AC-H Series

Page 1: ...nitor for element burnouts on heaters controlled with power regulators that used a three alarm method Normal monitoring is not possible for circuits that use a power regulator with a six alarm method...

Page 2: ...re linked with the control output value from the temperature controller Compatible with Gradient Settings of Power Controllers When using gradient settings with a power controller set a gate current l...

Page 3: ...tput specifi cations Com munica tions output Current input range 0 200 to 2 200 A 2 00 to 22 00 A 20 0 to 200 0 A 100 to 240 VAC ON OFF control SSR control Two current inputs for either single phase o...

Page 4: ...ut impedance 4 k min Cyclic and phase con trol 4 to 20 mA DC Burnout detection is possible for an input of 7 mA or greater Input impedance 50 max Outputs Relay contact outputs K8AC H C FLK One SPDT re...

Page 5: ...als and output terminals Dielectric strength 2 000 V for 1 min Between terminals and case Between power supply terminals CT primary terminals and gate input terminals communications terminals Between...

Page 6: ...VAC 0 3 A 30 VDC 1 A Maximum contact voltage 125 VAC 60 VDC Maximum contact current 1 A Maximum switching capaci ty 37 5 VA 30 W Minimum applicable load failure rate P value refer ence value 5 VDC 10...

Page 7: ...ct to the operating power supply All models 3 to 4 5 to 6 Outputs Outputs SSR open or short circuit detection results Outputs heater burnout or layer short circuit detection results K8AC H2 N transist...

Page 8: ...CTs for three phase heaters For three phase heaters always set the burnout alarm set values for both CT1 and CT2 5 6 3 4 Transistor Output K8AC H2 N FLK CT2 CT1 3 7 8 9 10 11 12 13 14 1 2 RS 485 X 4 5...

Page 9: ...ransistor Output K8AC H2 N FLK Heater Power supply Power Regulator Temperature Controller 4 to 20 mA current output Operation Description If the heater current detected at either CT1 or CT2 falls belo...

Page 10: ...o after one heater burns out with the current prior to the burnout i e the normal current taken as 1 3 In actual operation there may be effects from factors such as load heater imbalances so conduct a...

Page 11: ...s output accordingly SSR Short Circuit Detection If current is measured when there is no gate input an SSR short circuit error is detected and an alarm is output SSR Open Circuit Detection If current...

Page 12: ...Short Open Circuit Alarm Using the Power Regulator s Gradient Settings The power regulator s gradient settings can be used to prevent malfunction by setting the operation gate current level The relati...

Page 13: ...or over OFF for less than 4 mA SSR SSR error Lights when an SSR error occurs open or short circuit OFF when SSR is normal ALM Alarm Lights for heater burnout or overcurrent OFF at all other times Up k...

Page 14: ...pe P should be selected Type P is also selected for cyclic control Select the appropriate relay or transistor output specifications depending on the application K8AC H Parameter Settings Procedure Onl...

Page 15: ...freshed each time an alarm is output and it is saved in non volatile memory The value is saved when power is interrupted The number of outputs is not counted for the test function After counting to 99...

Page 16: ...r at least 1s Press the L key for at least 1 s Press the S key for at least 1 s Press the L key for at least 1s When the key is released Press the S key for at least 1 s Press the L and M keys Press t...

Page 17: ...layer short circuit detection function SSR open circuit detection function SSR short circuit detection function Output ON delay time Soft startup time Startup lock time Gate input function Alarm hyst...

Page 18: ...99 9 s 0 0 OFF SSR Short Circuit Detection Turns the SSR short circuit detection function ON and OFF ssht ON OFF OFF SSR Open Circuit Detection Turns the SSR open circuit detection function ON and OFF...

Page 19: ...te current level Sets the gate current level for SSR operation This setting is valid only when cyclic or phase control is selected as the heater control method sglv 4 0 to 20 mA 7 0 mA Cycle time 3 Se...

Page 20: ...ntact Approx 3 dia 18 22 Approx 6 dia Plug Contact Lead Plug 100 15 30 30 5 Two M3 Depth 4 max 12 dia 40 40 5 15 Current Transformer K8AC CT200 Pre wired Leads Current Transformer K8AC CT200L 1 8 76 4...

Page 21: ...o can cause unintended operation and may result in accident or corruption of the product 3 Do not use thinner or similar solvent for cleaning Use commercial alcohol 4 When discarding properly dispose...

Page 22: ...larm of the K8AC H P FLK when phase control is used Set the burnout alarm value of the K8AC H P FLK based on the current measurement value with the heater output at 100 This is because the burnout det...

Page 23: ...RODUCTS UNLESS OMRON S ANALYSIS CONFIRMS THAT THE PRODUCTS WERE PROPERLY HANDLED STORED INSTALLED AND MAINTAINED AND NOT SUBJECT TO CONTAMINATION ABUSE MISUSE OR INAPPROPRIATE MODIFICATION OR REPAIR A...

Page 24: ...em as a whole has been designed to address the risks and that the OMRON products are properly rated and installed for the intended use within the overall equipment or system Authorized Distributor In...

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