Monitoring Relays Tachometer Type SM 155 • Tachometer relay • Measuring ranges: 30 - 300 R.P.M. 200 - 2000 R.P.M. 1000 - 10000 R.P.M. • Knob-adjustable set level • Controlled by Namur/DIN 19234 sensor or metallic contact • Connection for moving-coil instrument • 10 A SPDT output relay • LED indication for relay ON • AC or DC power supply Product Description Ordering key SM 155 230 10K SM155 monitors the actual Knob adjustable set level on Housing RPMs of a motor by a relative scale. Function Namur/DIN 19234 sensor or Output a metallic contact. Type Power upply Measuring range Type Selection Plug Output Measuring range Supply: 24 VAC Supply: 115 VAC Supply: 230 VAC Supply: 24 VDC Circular SPDT 30 - 300 R.P.M. SM 155 024 300 SM 155 115 300 SM 155 230 300 SM 155 724 300 11 pins SPDT 20 - 2000 R.P.M. SM 155 024 2K SM 155 115 2K SM 155 230 2K SM 155 724 2K SPDT 1000 - 10000 R.P.M. SM 155 024 10K SM 155 115 10K SM 155 230 10K SM 155 724 10K Input Specifications Output Specifications Input Output SPDT relay Through terminals: Instrument connection Connection for moving-coil Metallic contact: 5, 6 instrument Namur sensor: 6, 7 Through pins 8, 9, pin 9 positive Measuring ranges Full scale deflection 1 mA Types: Internal resistance 110 Ω 300: 30 to 300 R.P.M. Rated insulation voltage 250 VAC 2K: 200 to 2000 R.P.M. Contact ratings (AgCdO) µ 10K: 1000 to 10000 R.P.M. Resistive loads AC 1 10A, 250 VAC Inversion Interconnecting pins 8, 11 DC 1 1 A, 250 VDC Short circuit current Small inductive loads AC 11 2.5 A, 230 VAC Pins 5, 6 5 mA DC 11 5 A, 24 VDC Pins 6, 7 10 mA 6 Mechanical life ≥ 30 x 10 operations Connection cable Can be extended as desired 5 Electrical life ≥ 2.5 x 10 operations Max resistance 100 Ω (at max load) Hysteresis approx 3% of set value Operating frequency ≤ 7200 operations/h Dielectric strength Dielectric voltage ≥ 2 kVAC (rms) Specifications are subject to change without notice (13.03.01) 1 SM 155 Supply Specifications General Specifications Power supply Overvoltage cat. III Reaction time Time between 2 pulses at Rated operational voltage (IEC 60664, IEC 60038) the set value of the poten- Through terminals 2, 10 tiometer 024: 24 VAC ± 15%, 45 to 65 Hz Accuracy of measurement ±3% 115: 115 VAC ± 15%, 45 to 65 Hz Indication for 230: 230 VAC ± 15%, 45 to 65 Hz Power supply ON LED, green 724: 24 VDC ± 15% Output relay ON LED, red Dielectric voltage 2 kV Environment Transient protection > 3kV Degree of protection IP 20 Rated operational power Operating temperature -20 to +50°C AC models 4 VA Storage temperature -50 to +85°C DC models 2 W Housing dimensions 35 x 80 x 83 mm Weight AC power supply Approx. 200 g DC power supply Approx. 125 g Approvals UL, CSA CE Marking Yes Mode of Operation/Level Setting The relay is controlled by The relay releases when the the set value. See hysteresis. resistance of the instrument mechanical triggering, e.g. number of R.P.M. is less than Instrument connection is 110 Ω. A deviation in the microswitch, reed relay, limit the set value. See hysteresis. A moving-coil instrument internal resistance of ± 100 switch etc. (examples 1 and with a scale calibrated in Ω results in an error of ± 1%. 2), or by electronic trigger- Example 2 and 4 R.P.M. can be connected to ing, e.g. inductive or capaci- By interconnecting pins 8 the SM 155. The instrument Level Setting tive sensors (NAMUR/DIN and 11 the relay function is has 1 mA full scale deflec- Knob adjustable on relative 19234) (examples 3 and 4). inverted, i.e. the relay releas- tion. scale es when the number of The relay generates max. 8.2 Examples 1 and 3 R.P.M. exceeds the set V on the instrument termi- The relay operates when the value. nals (pins 8 and 9) across an number of R.P.M. exceeds The relay operates when the internal resistance of 8.2 kΩ the set value. number of R.P.M. is less than in the relay. The ideal internal Wiring Diagrams Ex. 1, 2 - Mechanic triggering with metallic contact Ex. 3, 4 - Electr. trig. with NAMUR/DIN 19234 sensor 2 Specifications are subject to change without notice (13.03.01) SM 155 Operation Diagram Specifications are subject to change without notice (13.03.01) 3