Solid-state, Plug-in Current Sensor • Applicable to motor overcurrent protection and 3-phase AC current detection. • Inverse-type, start-up lock type, and instantaneous type overcurrent sensors available. • Instantaneous type under current sensor available. • Plug-in design simplifies installation, removal, and wiring. • DIN sized (48 mm x 96 mm) The SAO cannot be used in circuits with waveform distortion, inverter circuits, or with capacitor loads. Model Number Structure ■ Model Number Legend SAO-rnm 1 2 3 4 5 1. Basic model name 4. SAO: Current Sensor 2. Operating time characteristics R: Inverse type: inverse time both at starting and during oper ation Q: Instantaneous type with start-up lock 3. Detection function U: Undercurrent detection None: Overcurrent detection Product history N: New version

■ Characteristics (continued) Insulation resistance Time Changeover Setting: 1 SAO-Q Time Changeover Setting: 4 °.8 Current (% of operating current) Current (% of operating current)

Installation ■ Connection Internal Circuit SAO-R SAO-R Current Sensor Control voltage Power supply circuit Overcurrent detecting circuit Rectifying circuit Note: There is no polarity specification when using a DC power supply. SAO-Q Current Sensor SAO-SU Current Sensor Power supply circuit Overcurrent detecting circuit Rectifying circuit Control voltage Overcurrent detecting circuit Start-up mode time SV circuit Start-up detecting circuit Overcurrent detecting circuit SAO-S Current Sensor Test NORMAL: LED indicates operation. (ON for a steady current, OFF for an under current.) M Motor (A) Reset...

SAO ■ Connection Examples Overcurrent Detection Circuit SAO-R/SAO-Q/SAO-S R Undercurrent Detection Circuit SAO-SU R Stop Start Alarm buzzer Alarm buzzer Start Electromagnetic contactor Phase advancing capacitor Phase advancing capacitor SET-3 Current Converter Note: Provide the control power supply for the SAO Current Sensor from the contactor’s power supply side. If the control power supply is turned ON and the motor is started at the same time, operation inconsistent with the time SV may occur. Note: To prevent the buzzer sounding when power is turned ON, install a timer so that the buzzer...

Operation ■ SettingsCurrent Sensor Switch Settings Current Scale Multiplying Factor Decal Determine the current scale multiplying factor corresponding to the current SV range obtained from Table 1 and paste the current scale multiplying decal to the current sensor. For example, when the current setting range is 2 to 5 A, the decal no. is 0.5. LED Indicator The LED indicates that an overcurrent has occurred and the relay is operating. Setting Operating Time Set the time setting knob to the required time. The operating time is equal to the time scale value times the setting on the time changeover...

■ Operating and Setting Procedures SAO-R, -Q, -S Make the settings for the SAO Current Sensor and the SET-3D Current Converter according to the current of the load to be used. Steady Current The figures are steady current values. (Unit: A) Determining Current Sensor Settings 1. Determining the Current Scale Multiplying Factor Determine a current scale multiplying factor that matches the steady current obtained from the table, and attach that decal to the Current Sensor. For example, when the current setting range is 2 to 5 A, the label number is 0.5. 2. Setting the Operating Current Determine...

SAO-SU Make the settings for the SAO-SU Current Sensor and the SET-3D Current Converter according to the current of the load to be used. Steady Current Determining Current Sensor Settings 1. Determining the Current Scale Multiplying Factor Determine a current scale multiplying factor that matches the steady current obtained from the table, and attach that decal to the Current Sensor. For example, when the current setting range is 2 to 5 A, the label number is 0.5. 2. Setting the Operating Current Determine the operating current setting from the required steady current and the label number (i.e.,...

SAO ■ Checking Operation The following circuit can be used to check SAO-@ and SET-3@ characteristics. 200 VAC, 3-phase, 50/60 Hz R S T Control voltage Three-phase voltage regulator AC ammeter Cycle counter Auxiliary relay (15 A) Resistor

Dimensions Note: All units are in millimeters unless otherwise indicated. SAO-R/SAO-Q The Height of DIN Rail Mounting Current Converter SET-3A, SET-3B Mounting Holes Four, 6-dia. mounting holes or four, M5 mounting screw holes

Use a commercial frequency power supply only for the control power supply. Make sure that the polarity is correct when connecting the Current Converter and Current Sensor. It is not necessary to consider polarity when using a DC control power supply. The SET-3@ Current Converter is designed for use with a single SAO Current Sensor; do not connect two units to a single SET-3@ as in figure 1 below (even if a diode is included in the circuit). If the current transformer has sufficient capacity, the circuit in figure 2 is acceptable. Determine the necessary number of conductor runs from the table...

What is the procedure for using the SAO with a single phase? The following describes the single-phase operating procedure for the SAO. Models for single-phase circuits, however, are also available. Refer to SAO-@S. Connection Procedure Run the primary wires through any two of the three holes on the SET3 the number of times specified for the SET-3@. Can two SAO Current Sensors be used connected to one SET-3@? If not, can a diode or other device be inserted? It is not possible to connect two SAO Current Sensors to one SET-3@. The SET-3 output is designed so that the output voltage will match when...

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...