Current and Voltage Controls 1-Phase AC Current Control Type SJ 175 * AC current control relay * For AC standard current transformers * Current measuring range: .. A/1 AAC or .. A/5 AAC * Knob-adjustable current level * Latching at set level possible * Output: 10 A SPDT relay * Plug-in type module * S-housing * LED-indication for output ON * AC or DC power supply Product Description Ordering Key AC plug-in current metering relay. This relay is operating with commonly available standard current transformers, ..A/ 1A - .. A/5 A. Often used Housing Function Output Type Power supply Measuring range to detect over and underloads. The relay features builtin latch function which can be used e.g. to hold an alarm ON. SJ 175 024 1A Type Selection Plug Output Circ. SPDT Measuring ranges Supply: 24 VAC 0.2 - 1 AAC 1 - 5 AAC SJ 175 024 1A SJ 175 024 5A Supply: 115 VAC Supply: 230 VAC Supply: 24 VDC SJ 175 115 1A SJ 175 115 5A SJ 175 230 1A SJ 175 230 5A SJ 175 724 1A SJ 175 724 5A Input Specifications Supply Specifications Input Pins 5 & 7 Measuring ranges Types Power supply AC types Rated operational voltage Through pins 2 & 10 024 115 230 Voltage interruption Dielectric voltage Rated impulse withstand volt. AC current Ranges SJ 175 ... 1A SJ 175 ... 5A Max. overload current 0.2 - 1 AAC 1 - 5 AAC 1 A: 5 A: Latching Internal resist. 0.1 0.02 8 AAC (30 sec.) 40 AAC (10 sec.) 25 AAC (30 sec.) Interconnect pins 8 & 9 latching at set level, no latching at DC supply Specifications are subject to change without notice Power supply DC types Rated operational voltage Through pins 2 & 10 724 Dielectric voltage Rated impulse withstand volt. Rated operational power AC supply DC supply Overvoltage cat. III (IEC 60664) (IEC 60038) 24 VAC 15%, 45 to 65 Hz 115 VAC 15%, 45 to 65 Hz 230 VAC 15%, 45 to 65 Hz 40 ms 2 kVAC (rms) (supply/elect.) 4 kV (1.2/50 s) (line/neutral, line/line), no direct connection to electronics Overvoltage cat. III (IEC 60664) (IEC 60038) 24 VDC 15% None (supply/elect.) 800 V (1.2/50 s) 2.5 VA 1.5 W 1 SJ 175 Output Specifications General Specifications Output Rated insulation voltage Reaction time SPDT relay 250 VAC (rms) (cont./elect.) (micro gap) 10 A/250 VAC (2500 VA) 1 A/250 VDC (250 W) 10 A/25 VDC (250 W) 2.5 A/230 VAC 5 A/24 VDC 30 x 106 operations 2.5 x 105 operations (at max. load) 7200 operations/h Contact ratings (AgCdO) Resistive loads AC 1 DC 1 or Small inductive loads AC 15 DC 13 Mechanical life Electrical life AC 1 Operating frequency Dielectric strength 2.0 kVAC (rms) (cont./elect.) Dielectric voltage Rated impulse withstand volt. 4 kV (1.2/50 s) (cont./elect.) (IEC 60664) Relay operates: = 22 ms Relay releases: = 2.2 s worst case reaction time may be up to 5 x 0 to +10% on max. Min. actual level set level Accuracy Indication for Output ON Environment Degree of protection Pollution degree Operating temperature Storage temperature Weight AC supply DC supply Approvals LED, yellow (IEC 60947-1) IP 20 B (IEC 60529) 2 (IEC 60664) -20 to +50C (-4 to +122F) -50 to +85C (-58 to +185F) 200 g 125 g UL, CSA Mode of Operation The SJ 175 measures the average of a sinusoidal current. The set point, calibrated to rms-value, is set on the builtin potentiometer. Example 1 AC current metering The relay operates when the measured current from the standard through-primary transformer exceeds set point. The relay releases when the current value drops 10% (see hysteresis). Example 2 AC current limiter - latching The diagram shows the relay connected to standard through-primary transformer as a current limiter with latching. The relay operates when the measured current reaches set point. Thus a contactor can be activated either by interrupting the primary current wholly/partly, or by shortcircuiting the input (pins 5 and 7) of the relay. current is below set point less hysteresis. Note: Internal connection between pins 7 and 10 at DC power supply. No current is to pass through this internal connection. The latching is reset when a new measurement is required, provided that the measuring Wiring Diagrams Example 1 Example 2 Latch PE = Pin 7 Power supply SJ 175 2 Power supply SJ 175 Specifications are subject to change without notice SJ 175 Range Setting Range setting Relay set point adjustable on absolute scale. Hysteresis Approx. 10%. The hysteresis may be extend- Accessories ed to 75% by connecting a resistor between pins 8 and 9. Resistor limits are 470 k and 3 k (0.25 W). The hysteresis is increased by decreasing resistance. Sockets S 411 Hold down spring HF Mounting rack SM 13 Socket covers BB 4 Front mounting bezel FRS 2 Potentiometer lock PL 1 Through-primary current transformer, 1 or 5 A, secondary output. For further information refer to "Accessories". Operation Diagrams Example 1 Example 2 Power supply Power supply Latching Set value Set value - 10% Input voltage from pins 5 & 7 Input voltage from pins 5 & 7 Relay ON Relay ON Specifications are subject to change without notice 3