K8AC-H
4
Specifications
Ratings
*1. The gate input enables correct measurement by syncing to heater control.
When using it with ON/OFF control, receive the relay contact output from the temperature controller or other controller with a 24-VDC auxiliary
relay and then use this signal as the gate input signal to the K8AC.
The gate function can also be disabled. If it is disabled, the gate input can be used as a normal undercurrent/overcurrent relay.
*2. When using the K8AC-H for a 380 to 480-V AC power supply circuit, use a step-down transformer. Contact your OMRON representative for
information on transformers.
*3. Order the Current Transformers separately.
Heater control method Models for ON/OFF control (e.g., SSRs or contactors) Models for phase control and cyclic control
Item Model K8AC-H@@C@-FLK K8AC-H@@P@-FLK
Power supply voltage 100 to 240 VAC (50/60 Hz) *2
Operating voltage range 85% to 110% min. of the rated power supply voltage (85 to 264 V)
Power consumption
(at max. load) 10 VA max.
Applicable circuits Single-phase or three-phase (with same model)
Applicable control methods
ON/OFF control (e.g., temperature controller with relay output)
SSR control (e.g., temperature controller with voltage output)
Cyclic control and phase control (e.g., temperature controller with current output)
Input signal and applicable Current
Transformer
Current measurement via two special Current Transformers (Burnout alarm set value can be set separately for each Current
Transformer.)
Refer to Current Measurement Ranges by Model on page 6 for information on the current measurement range and
applicable Current Transformer.
Measurement method Instantaneous measurement using root-mean-square values
Gate input
signal *1
ON/OFF control Voltage = 12/24 VDC (continuous input possible to 30 VDC)
Input impedance = 4 kΩmin. ---
SSR control
ON voltage: 9.6 VDC max., OFF voltage: 1 VDC min.
Minimum voltage pulse ON time for burnout detection:
200 ms min.
Input impedance = 4 kΩmin.
---
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 Ωmax.
Outputs
Relay contact outputs:
K8AC-H@@@C-FLK
One SPDT relay contact output
Same output used for heater burnout, SSR short circuit, SSR open circuit, and heater layer short circuit alarms.
0.3 A at 125 VAC (resistive load), 1 A at 30 VDC (resistive load)
Maximum switching capacity: 37.5 VA, 30 W
Mechanical durability: 50 million operations min., electrical durability: 100,000 operations min.
Transistor outputs
(NPN open-collector):
K8AC-H1@@T-FLK
Two transistor outputs (NPN open-collector)
One ALM output: Outputs heater burnout alarm or heater layer short circuit alarm.
One SSR error output: Outputs SSR short circuit alarm or SSR open circuit alarm.
12 to 24 VDC, 50 mA max.
OFF leakage current: 100 µA max., ON residual voltage: 1.5 V max.
Transistor outputs:
K8AC-H2@@N-FLK
Two transistor outputs: Can be used either NPN open-collector outputs or PNP equivalent outputs.
One ALM output: Outputs heater burnout alarm or heater layer short circuit alarm.
One SSR error output: Outputs SSR short circuit or SSR open circuit detection.
12 to 24 VDC, 50 mA
OFF leakage current: 100 µA max., ON residual voltage: 1.5 V max.
Communications RS-485 1200, 2400, 4800, 9600, 19200 bps (CompoWay/F)
Indication method 7-segment digital display: No. of display digits: 4 (red)
LED status indicators: RUN (green), ADJ (orange), SET (orange), GATE (orange), SSR (orange) and ALM (orange)
Main functions
Heater burnout alarm, heater layer short circuit alarm, SSR short circuit detection, SSR open circuit detection, voltage
fluctuation compensation, output ON-delay timer, energy-saving mode, key protection, and power supply voltage
measurement
Ambient
temperature
Operating −10 to 55°C (with no icing or condensation)
Storage −25 to 65°C (with no icing or condensation)
Ambient
humidity
Operating 25% to 85% (with no condensation)
Storage 25% to 85% (with no condensation)
Altitude 2,000 m max.
Accessories Instruction sheet
Case material PC (Polycarbonate)
Case color N1.5 (clear black)
Mounting method Mounting to a DIN Track
