omRon Three-phase Asymmetry and Phase-sequence Phase-loss Relay K8AK-PA Ideal for 3-phase Voltage Asymmetry Monitoring for Industrial Facilities and Equipment. • Greater resistance to inverter noise. new • Monitor voltage asymmetry, phase sequence, and phase loss for three-phase 3-wire or 4-wire power supplies with just one Unit. Switch setting for 3-phase 3-wire or 3-phase 4-wire power supply. • One SPDT output relay, 5 A at 250 VAC (resistive load). •World-wide power specifications supported by one Unit (switchable). • Relay status can be monitored using LED indicator. A Refer to Safety Precautions on page 9. Refer to page 8 for commonly asked questions. Ordering Information List of Models Rated input* Note: Three-phase, three-wire or four-wire and the input range are switched using a DIP switch. * The power supply voltage is the same as the rated input voltage. Single K8AK Monitors 3-phase Power Supply with 3 or 4 Wires Monitoring Relays can be used to monitor 3-phase power supplies with 3 or 4 wires simply by changing DIP switch settings. [Phase to phase voltage (3 wires)] | Phase to neutral voltage (4 wires)]

Specifications Input frequency •Relationship of Mounting Distance between K8AK-PA Relays and Ambient Temperature (Reference Values) The following diagram shows the relationship between the mounting distances and the ambient temperature. If the relay is used with an ambient temperature that exceeds these values, the temperature of the K8AK may rise and shorten the life of the internal components. DIN Track Distance between products: d

K8AK-PA ConnectionsTerminal Diagram2. Use the recommended ferrules if you use twisted wires.Wiring Example Timing Charts •Voltage Asymmetry and Phase Sequence/Phase Loss Operation Diagram Operation Indicators Alarm indicator _ Relay t1: Power ON lock (1 s or 5 s) Phase loss operation Alarm indicator Relay 11-14 hhh Flashing Flashing Flashing lllllllll lllllllll 111111111 L1 and L2 are also used for the power supply. If the voltage becomes very low, the indicator will turn OFF. The indicator will flash once per second after an incorrect phase is detected and once per 0.5 second during the detection...

NomenclatureFront •Indicators Item * The input across L1 and L2 is used for the internal power supply. Therefore, the power indicator will not be lit if there is no input across L1 and L2. •Setting Knobs Item Note: 1. Use either a solid wire of 2.5 mm2 maximum or a ferrule with insulating sleeve for the terminal connection. The length of the exposed current-carrying part inserted into the terminal must be 8 mm or less to maintain dielectric strength after connection. For 2.5 mm2 or For ferrules with smaller solid wires an insulation sleeve. Recommended ferrules Phoenix Contact • Al 1,5-8BK...

•Input Connect to L1, L2, and L3 (for three-phase three-wire mode) or L1, L2, L3, and N (for three-phase four-wire mode), depending on the mode selected using pin 2 on the DIP switch. The Unit will not operate correctly if the DIP switch setting and the wiring do not agree. Make sure the phase sequence is wired correctly. The Unit will not operate normally if the phase sequence is incorrect. •Outputs Terminals 11, 12, and 14 are output terminals for SPDT. * Use the recommended ferrules if you use twisted wires. The power ON lock time, number of wires, and rated voltage are set using the DIP switch...

K8AK-PA Setting Method ●Asymmetry The asymmetry rate is set using the asymmetry rate knob (ASY.) The setting range is 2% to 22% of the rated input. Turn the knob while there is an input to the input terminals until the alarm indicator flashes (when the set value and the input have reached the same level.) Use this as a guide to make the setting. The rated input depends on the model and DIP switch setting. Example: K8AK-PA1 with Pin 2 Turned OFF (Three-phase, Three-wire Mode) and Pins 3 and 4 Turned OFF (Rated Voltage of 200 V) The rated input voltage is 200 VAC and the setting range is 4 to 44...

Checking Operation With the rated input voltage applied, gradually change the voltage to any one phase. The Unit will operate when the difference between the maximum and minimum voltage phases reaches or exceeds the asymmetry operating value. Asymmetry operating value = Rated input voltage × Asymmetry set value (%) Example: For monitoring mode set to three-phase three-wire monitoring, a rated voltage of 200 V, and an operating time of 5 s. Note: K8AK-PA@ output relays are normally operative. L1 Alarm indicator T T: Operating time (0.1 to 30 s) T1: Power ON lock time (1 s or 5 s) L1 0 to 150 V...

Safety Precautions Be sure to read the precautions for all models in the website at the following URL: http://www.ia.omron.com/. Warning Indications There is a risk of minor electrical shock, fire, or device failure. Do not allow any pieces of metal, conductors, or cutting chips that occur during the installation process to enter the product. Explosions may cause minor injuries. Do not use the product in locations with inflammable or explosive gases. There is a risk of minor electrical shock, fire, or device failure. Do not disassemble, modify, repair, or touch the inside of the product. Loose...

Precautions for Safe Use 1. Do not use or store the product in the following locations. • Locations subject to water or oil • Outdoor locations or under direct sunlight • Locations subject to dust or corrosive gases (particularly sulfurizing gases, ammonia, etc.) • Locations subject to rapid temperature changes 5. To reduce the error in the setting knob, always turn the setting knob from the minimum setting toward the maximum setting. 6. Phase loss is detected only when the power supply to the motor is turned ON. Phase loss during motor operation is not detected. 7. Phase loss can be detected...

Terms and Conditions Agreement Read and understand this catalog. Please read and understand this catalog before purchasing the products. Please consult your OMRON representative if you have any questions or comments. Warranties. (a) Exclusive Warranty. Omron’s exclusive warranty is that the Products will be free from defects in materials and workmanship for a period of twelve months from the date of sale by Omron (or such other period expressed in writing by Omron). Omron disclaims all other warranties, express or implied. (b) Limitations. OMRON MAKES NO WARRANTY OR REPRESENTATION, EXPRESS OR...