K8AC-H
7
Connections
Terminal Arrangement
K8AC-H2
@@@
-FLK
K8AC-H1
@@@
-FLK
Output Circuits
Contact Outputs
Note: For contact outputs, the same outputs are used for SSR error
and for heater burnouts and heater layer short circuit alarm
outputs.
Transistor Output
K8AC-H2
@@
N-FLK
The transistor output of the K8AC-H2
@@
N uses a photocoupler for
isolation with the internal circuits, and so either an NPN open-
collector output or a PNP equivalent output can be used.
K8AC-H1
@@
T-FLK
7
CT1
CT2
Linear current
4 to 20 mA DC
RS-485
8
9
10
7
8
9
10
11
12
13
14
11
Voltage pulse
12 VDC or
24 VDC
12
H8AC-H2
@
C
@
Gate input
H8AC-H2
@
P
@
11
12
13
14
Communications
Current inputs
1
2
Power supply voltage
100 to 240 VAC
A(
−
)
B(
+
)
COM
125 VAC,
0.3 A AC
30 VDC,
1 A DC
12 to 24 VDC,
50 mA DC
4
5
6
5
6
Outputs
H8AC-H2
@@
N
H8AC-H2
@@
C
1
2
3
4
5
6
12 to 24 VDC,
50 mA DC
3
4
7
CT1
CT2
RS-485
8
9
10
7
8
9
10
11
12
13
14
11
12
11
12
13
14
1
2
Power supply voltage
COM
COM
4
5
6
4
5
6
1
2
3
4
5
6
Linear current
4 to 20 mA DC
Voltage pulse
12 VDC or
24 VDC
H8AC-H1
@
C
@
Gate input
H8AC-H1
@
P
@
Communications
Current inputs
100 to 240 VAC
A(
−
)
B(
+
)
125 VAC,
0.3 A AC
30 VDC,
1 A DC
12 to 24 VDC,
50 mA DC
Outputs
H8AC-H1
@@
T
H8AC-H1
@@
C
Terminals
Name
Description
Applicable models
1 to 2
Power supply voltage
Connect 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
(transistor output)
5 to 4,
6 to 4
K8AC-H1
@@
T
(NPN open-collector output)
5, 6 to 4
Outputs an OR of the status of all alarms.
K8AC-H
@@@
C (relay output)
7 to 8
Current inputs
Connect to CT1. Current input from CT1 secondary-side output.
All models
9 to 10
Connect to CT2. Current input from CT2 secondary-side output.
11 to 12
Gate input
Connect to gate signal (voltage pulse).
K8AC-H
@@
C
@
Connect to a 4 to 20-mA gate signal.
K8AC-H
@@
P
@
13 to 14
Communications
Connect to host device for RS-485 communications.
All models
Note: 1. Terminals 4 to 6:
Alarm output
terminals. Depend
on the output type
(relay contact
output or transistor
output).
2. Terminals 11 and
12: Gate input
terminals. Depend
on the heater
control type (ON-
OFF/SSR control
or cyclic/phase
control).
CT2
CT1
7
8
9
10
A/D
conversion
−
+
A/D
conversion
−
+
Current Input Circuits
CT Inputs (Heater Current)
4
5
6
COM
Relay
drive
circuit
N.C. contact
N.O. contact
+12 V
6
5
SSR alarm output
Heater burnout,
heater layer short circuit,
overcurrent alarm output
4
3
Transistor
drive
circuit
Transistor
drive
circuit
NPN Output
PNP Equivalent Output
Load
Load power supply
Load power supply
Load
4
5
6
Transistor
drive circuit
Transistor
drive circuit
COM
SSR alarm output
Heater burnout, heater layer short
circuit, overcurrent alarm output
