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SitemapDigital Heater Element Burnout Detector
K8AC-H
A high-precision Heater Element Burnout Detector compatible with a wide-range of heater control methods.
Data Sheet (1578KB)
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Ratings and Specifications
Ratings
| Heater control method | Models for ON/OFF control (e.g., SSRs or contactors) | Models for phase control and cyclic control | |
| 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 Data Sheet. | ||
| 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 k Ω min. | --- |
| 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 k Ω min. | --- | |
| --- | 4 to 20 mA DC (Burnout detection is possible for an input of 7 mA or greater.) Input impedance = 50 Ω max. | ||
| 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 μ A 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 | ||
*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.
Characteristics
| Heater control method | Models for ON/OFF control (e.g., SSRs or contactors) | Models for phase control and cycle control | |
| Model | K8AC-H [][][]C[]-FLK | K8AC-H [][]P[]-FLK | |
| Heater current input (at 10 to 30°C) category II | Input range | K8AC-H []1[][] : 0.200 to 2.200 A (Current Transformer: K8AC-CT20S (5.8 dia.), K8AC-CT20L (12 dia.) *1) K8AC-H []2[][] : 2.00 to 22.00 A (Current Transformer: K8AC-CT20S (5.8 dia.), K8AC-CT20L (12 dia.) *1) K8AC-H []3[][] : 20.0 to 200.0 A (Current Transformer: K8AC-CT200 (12 dia.), K8AC-CT200L (30 dia.) *1) | |
| Measurement accuracy | ± 3% rdg ± 10 digits max. *2 | ± 6% rdg ± 10 digits max. *2 | |
| Voltage fluctuation compensation category II | Input range | 85 to 264 VAC | |
| Measurement accuracy | ± 3% rdg ± 10 digits max. | ||
| Gate input | Input range | 0 to12 VDC or 0 to 24 VDC ON: 9.6 VDC max., OFF: 1 VDC min. | 4 to 20 mA DC |
| Display cycle | Selectable: Immediate, 0.2 s, 0.5 s, 1.0 s | ||
| Output ON-delay time | 0.0 to 99.9 s (operating time) | ||
| Soft start time | 0.0 to 99.9 s (used when using the soft start function of a Power Controller) | ||
| Output reset method | Automatic reset | ||
| Alarm hysteresis | 1 to 999 digits | ||
| Output response time | 500 ms max. | 3.5 s max. | |
| Insulation resistance | 20 M Ω min. Between terminals and case Between power supply terminals/CT primary terminals and gate input terminals/communications terminals Between power supply terminals/CT primary terminals and output terminals Between gate input terminal/communications terminals 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 power supply terminals/CT primary terminals and output terminals Between gate input terminal/communications terminals and output terminals | ||
| Noise immunity | Power supply terminals normal/common mode: ±1,500 V (startup 1-ns square-wave noise, pulse width: 1 μ s/100 ns) | ||
| Vibration resistance | Vibration: 10 to 55 Hz, Acceleration: 50 m/s2 for 5 min with 10 sweeps each in X, Y, and Z directions | ||
| Shock resistance | 150 m/s2 (100 m/s2 for relay contacts) 3 times in 6 directions in X, Y, and Z directions | ||
| Maximum allowable input | Current Transformer primary current | K8AC-H[]1[][] : 4 A: 30 s, 12 A: 1 s K8AC-H[]2[][] : 40 A: 30 s, 120 A: 1 s K8AC-H[]3[][] : 400 A: 30 s, 1,200 A: 1 s | |
| Gate signal: 4 to 20 mA | 40 mA DC continuous | ||
| Voltage pulse gate input | 30 VDC continuous | ||
| Input impedance | Gate signal: 4 to 20 m | 50 Ω max. | |
| Voltage pulse gate input | 4 k Ω min. | ||
| Weight | Approx. 200 g | ||
| Memory protection | Non-volatile memory (number of writes: 100,000 operations) | ||
| Installation environment | Installation Category 2, Pollution Class 2 | ||
| Approved standards | UL61010-1 and CAN/CSA C22.2 No.61010-1-04 (UL pending) EN 61010-1 (IEC 61010-1) ( TÜV evaluation) | ||
| EMC | EMI: EN61326 Industrial applications Radiated Interference Electromagnetic Field Strength: EN55011 Group 1, class A Noise Terminal Voltage: EN55011 Group 1, class A EMS: EN61326 Industrial applications ESD Immunity: EN61000-4-2: 4 kV (contact discharge), 8 kV (air discharge) Electromagnetic Immunity: EN61000-4-3: 10 V/m 1 kHz sine wave amplitude modulation (80 MHz to 1 GHz) Fast Transient Burst Immunity: EN61000-4-4: 2 kV (power line), 1 kV (I/O signal line) Surge immunity: EN61000-4-5: 1 kV (line to line, power line), 2 kV (line to ground, power line) Conducted Noise Immunity EN61000-4-6: 3 V (0.15 to 80 MHz) Voltage Dip/Interrupting Immunity EN61000-4-11: 0.5 cycle, 0.180 °, 100% (rated voltage) | ||
*1.The Current Transformers are sold separately.
*2.The values for measurement current apply when the K8AC-H is used in combination with a Current Transformer.
Current Measurement Ranges by Model
I/O Ratings
Relay Contact Output
| Load | Resistive load (cosΦ = 1) |
| Rated load | 125 VAC, 0.3 A, 30 VDC, 1 A |
| Maximum contact voltage | 125 VAC, 60 VDC |
| Maximum contact current | 1 A |
| Maximum switching capacity | 37.5 VA, 30 W |
| Minimum applicable load (failure rate P value, reference value) | 5 VDC, 10 mA |
| Mechanical life expectancy | 50,000,000 operations min. (at a switching frequency of 18,000 times/h) |
| Electrical life expectancy (Ambient temperature condition: 20°C) | 100,000 operations min. (at rated load and switching frequency of 1,800 times/h) |
Transistor Output
| Maximum load voltage | 12 to 24 VDC (+10%, - 15%) |
| Maximum load current | 50 mA |
| OFF leakage current | 100 μ A max. |
| ON residual voltage | 1.5 V max. |
Communications Specifications
| Communications | RS-485 |
| Transmission method | Two-wire, half-duplex |
| Synchronization method | Start-stop synchronization |
| Baud rate | 1,200, 2,400, 4,800, 9,600, or 19,200 bps |
| Transmission code | ASCII |
Caution: In the interenst of product improvement, specifications are subject to change without notice.
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