K8AC-H
8
External Connection Example
Wiring Method When Using the K8AC-H with SSR Control Heaters
Wiring Method When Using the K8AC-H with ON/OFF Control Heaters
5
6
3
4
Transistor Output
K8AC-H2
@@
N-FLK
SSR
CT2
CT1
4
3
5
6
7
8
9
10
11
12
13
14
1
2
RS-485
Heater
Power supply
Temperature
Controller
(DC voltage output)
Operation Description
• If the heater current detected at either CT1 or CT2 falls below the
burnout alarm set value, an alarm is output. The burnout alarm set
value can be set separately for CT1 and CT2.
No burnout alarm is output, however, when the temperature con-
troller control output is OFF.
Burnouts are detected only while the temperature controller control
output is being input to the gate input terminals (11 and 12).
Faulty outputs do not occur because heater burnout detection is
linked with the temperature controller.
• The minimum burnout detection time is 200 ms. Shorter burnouts
are not detected.
• Turn ON the voltage fluctuation compensation function (default:
OFF) to detect power supply voltage fluctuations and automatically
compensate the burnout alarm value. Also, turn ON the voltage
fluctuation compensation function to detect minor current fluctua-
tions.
Correct Usage
• Always take the power supply voltage from the primary side of the
SSR.
• Use temperature controllers with a 12 or 24-VDC voltage output
(30 VDC max.).
• CT1 and CT2 are special products. Use the K8AC-CT
@@
.
• The CTs do not have polarity.
• Connect only one CT for single-phase heaters.
Connect two 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
6
Heater
Power supply
Contactor
Temperature
Controller
(relay output)
24-VDC
power supply
Operation Description
• If the heater current detected at either CT1 or CT2 falls below the
burnout alarm set value, an alarm is output. The burnout alarm set
value can be set separately for CT1 and CT2.
No burnout alarm is output, however, when the temperature con-
troller control output is OFF.
Burnouts are detected only while the temperature controller control
output is being input to the gate input terminals (11 and 12).
Faulty outputs do not occur because heater burnout detection is
linked with the temperature controller.
• The minimum burnout detection time is 200 ms. Shorter burnouts
are not detected.
• Turn ON the voltage fluctuation compensation function (default:
OFF) to detect power supply voltage fluctuations and automatically
compensate the burnout alarm value. Also, turn ON the voltage
fluctuation compensation function to detect minor current fluctua-
tions.
Correct Usage
• Always take the power supply voltage from the primary side of the
SSR.
• Use a temperature controller with relay output.
• The input to the gate input terminals (11 and 12) must be a DC volt-
age input, so wire the 24-VDC power supply as shown in the dia-
gram to the left.
• CT1 and CT2 are special products. Use K8AC-CT
@@
.
• The CTs do not have polarity.
• Connect only one CT for single-phase heaters.
Connect two CTs for three-phase heaters.
• For three-phase heaters, always set the burnout alarm set values
for both CT1 and CT2.
