ACM3P Series www.murata-ps.com s Three-Phase AC Ammeters Actual size C ® US E156931 FEATURES PRODUCT OVERVIEW Measure and display the true-rms current of 3-phase power systems Universal 85-264Vac (47-63Hz) operating supply range Three built-in current transformers measure up to 100A per phase Ideal for power distribution units (PDUs) and backup power systems Low power consumption: less than ¼watt from 120Vac supply One-piece polycarbonate housing fits ‘0U’ & ‘1U’ rack spaces Low-profile surface mount design occupies minimal behind-the-panel space Available in red, green, or blue LED-displays with phase annunciators Murata Power Solutions’ ACM3P series 3-phase AC ammeters measure and display the true-rms values of 2- or 3-phase ac mains current. A front panel touch switch enables the selection of a continuous reading of any of the three phases. All ACM3P ammeters are functionally complete, with built-in L1, L2, and L3 current transformers—no other user-supplied components or hardware are required. ACM3P series AC ammeters are available with a 0-100A input range (150A peaks) and provide a resolution of 0.1 Amp. Their 85-264Vac (47-63Hz) operating supply range makes these ammeters perfect for worldwide 3-phase current monitoring applications. And, unlike conventional average-responding products, ACM3P ammeters can accurately display the true-rms values of triangle waves, square waves, and other irregularly shaped AC current waveforms, with an accuracy of ±2% of full scale. Their large (0.36"/9.2mm), bright LED display, available in a choice of red, blue, or green, enables ACM3P ammeters to be easily readable from as far as 15 feet (5 meters). All units are packaged in a one-piece, vibration resistant, polycarbonate housing that can be installed in vertical ‘0U’ or horizontal ‘1U’ rack spaces. Their miniature size is ideal for UPS backup power sources, power strips, alternative energy metering, and any other applications that require precise monitoring of 2- or 3-phase ac current. Low Cost; approvals to UL/cUL/IEC/61010-1 SIMPLIFIED SCHEMATIC DIAGRAM L1 L2 L3 PHASE 1 +5V PHASE 2 L1 L2 PHASE 3 A/D CONVERTER L3 +5V CURRENT LIMITED 85-264 Vac 47-63 Hz SUPPLY B A +5V AC/DC CONVERTER MICROCONTROLLER For full details go to www.murata-ps.com/rohs SEL www.murata-ps.com/support MPM_ACM3P Series.A04 Page 1 of 6 ACM3P Series Three-Phase AC Ammeters Performance/Functional Specifications Typical at TA=+ 25ºC, 120Vac @ 50Hz, unless otherwise noted Measurement Limits Min. Typ. Max. Units AC (rms) Current, L1, L2, L3 ➀ 0.0 — 100.0 Amperes Overcurrent Rating ➁ 1.5 x Rated full-scale current Performance Sampling Rate 1.5 samples/sec Current Accuracy ➂ ±2% Measurement Bandwidth (L1, L2, L3) ±3% 14kHz Temperature Drift (0 to 60ºC) 0.5 Counts/ºC Zero-Current Reading (within 1 sec.) 1 UL/IEC61010-1 Counts Measurement category II Supply Voltage (TB1) All Models 85 120 264 Vac/47-63Hz ACM3P-X-AC1-R-X-C 35 50 110 mA ACM3P-X-AC1-G-X-C 50 75 165 mA ACM3P-X-AC1-B-X-C 50 75 165 mA Supply Current ➃ Power Supply Terminal Block (TB1) Wire Size 16-22AWG, solid or stranded Insulation Strip Length 6.4mm (0.250 in) Screw Tightening Torque 0.4Nm (3.6 lb-in) Rated Voltage Display 4 Digit LED, 9.14mm (0.36in) high Overrange Indication Flashing display Decimal Point Selection Automatically Set Physical/Environmental Operating Temperature: Storage Temperature: Humidity (non-condensing): Dimensions: 0 — +60 ºC -40 — +75 ºC 0 — 85 % See mechanical specifications Weight, all models 2.6 oz (74g) Notes ➀ Specified full-scale currents are those passing through the power meter’s built-in current transformer’s primary load-circuit. See Notes 2 and 3 below for additional information. ➁ The overcurrent rating of 1.5 x the rated full-scale current is a continuous rating and applies to the current passing through the built in current transformer. Accuracy is guaranteed up to the rated current level. ➂ Power Meters are calibrated with near full-scale 50Hz sine-wave inputs. ➃ All specified maximum supply currents are steady state. Larger surge currents can occur at initial application of line power. ORDERING INFORMATION ACM3P-4-AC1-R-C 100A, 85-264Vac Supply, Red LED Display ACM3P-4-AC1-G-C 100A, 85-264Vac Supply, Green LED Display ACM3P-4-AC1-B-C 100A, 85-264Vac Supply, Blue LED Display ! IMPORTANT! To ensure safe and reliable operation, ACM3P ammeters must be installed and serviced by qualified technical personnel. Contact Murata Power Solutions if there is any doubt regarding their installation or operation. 1. Measurement Type: ACM3P series 3-phase ammeters employ a precision energy metering integrated circuit and a low-power microcontroller to measure and display the rms value of 2- or 3-phase ac-mains current. However, while the unit has an upper bandwidth of 14kHz, dc components or frequencies below 47Hz will not be measured accurately. 2. Basic Operation: Upon application of ac power to TB1, the unit will first perform a self-test routine and then continuously display amperes, with one of the three phase-annunciator LEDs illuminated (L1, L2, or L3). The display will remain fixed in one of these reading modes as long as the front panel ‘SEL’ button is not touched. Assuming phase L1 is initially illuminated, momentarily touching the ‘SEL’ button two times in succession will cycle the display to phase L2, and then to phase L3. Momentarily touching ‘SEL’ a third time will return the unit back to displaying phase L1 current. If power is removed and then restored, the ACM3P will perform a self-test and then return to displaying the last selected phase, i.e., the phase it displayed just before power was removed. 300Vac Display Type and Size TECHNICAL NOTES Configuring for 2-Phase Operation: As shipped, ACM3P ammeters are configured to measure and display 3-phase currents (L1, L2, and L3 current transformers are all active). The unit can be set to display 2-phase currents (only L1 and L2 are active) by performing the following procedure: A. Press and hold the SEL button for approximately five seconds and then release the button once the words “LinE SEt” appear on the display. B. Briefly tapping the SEL button will alternate the display reading between ‘2-Ph’ and ‘3-Ph’ each time SEL is tapped. C. To change the factory default 3-phase mode to 2-phase, leave the display fixed in the ‘2-Ph’ reading for at least five seconds. To revert the unit back to 3-phase operation simply repeat the above procedure but, in step C, allow the unit to display a fixed ‘3-Ph’ for at least five seconds. 3. Overrange Indication: ACM3P ammeters have an overcurrent rating of 1.5 times rated current, or 150A. However, accuracy is only guaranteed up to 100A, and the display will flash on and off when the current is at or above 120A. 4. Calibration: Due their digital design, ACM3P ammeters cannot be calibrated in the field. ACM3P ammeters are factory-calibrated to meet their specified accuracies with the factory supplied current transformers. Use of any other current transformers will produce significant errors. Contact Murata Power Solutions if additional information is required regarding calibration, setup, or any other technical issue pertaining to ACM3P ammeters. www.murata-ps.com/support MPM_ACM3P Series.A04 Page 2 of 6 ACM3P Series Three-Phase AC Ammeters TECHNICAL NOTES, CONTINUED 8. Connector Torque Ratings: It is important to tighten TB1’s screwterminals to their rated torque specification of 3.6 pound-inches (0.4Nm). Proper tightening will minimize connector losses and ensure safe, reliable operation. 5. Wiring: All power supply and load wiring must be rated for the voltages and currents they will carry and must comply with any code or application-mandated requirements pertaining to the user’s specific installation. 9. Isolation: Except for the 2-56 thread metallic mounting studs, all of the ACM3P ammeter’s internal components (printed circuit board, resistor, capacitors, current transformers L1, L2 and L3’s secondary leads, etc.) are at the ac-mains potential connected to TB1. ACM3P ammeters are designed to be powered from one ac power-source only. Any other connection schemes could introduce significant measurement errors. 6. Supply Fusing, and Grounding: Wires specified in the Functional Specifications section must be used for making connections to ACM3P series ammeters’ TB1 terminal block. No connection is required for earth/chassis ground. ACM3P series ammeters are not internally fused. Terminal block TB1 is to be used only for powering the ammeter's internal circuitry; it must not be used to supply power to external loads. The supply wires feeding these power meters must be fused with a 0.5A/250V time delay/time lag fuse, in accordance with applicable regulatory codes. Wire insulation must be stripped to within ±10% of the stated dimensions, and wires should be inserted into TB1 such that their insulation is not pinched by the screw terminal. 7. Current Transformer Phasing: Since the ACM3P only measures amperes, transformer phasing is not required. ‘Phasing’ refers to the direction of the current-carrying wire as it passes through the primary hole of each of the three built-in current transformers. The three built-in current transformers have a dielectric breakdown rating of 2kV minimum, allowing them to safely monitor 480V, 3-phase ac mains currents. This dielectric rating pertains only to the insulated load-carrying wire as it passes through the built-in CT’s primary hole. However, attention must still be paid to ensure adequate wire-to-wire spacings, and wire-to-metallic surface spacings. Properly rated wiring and fusing must be used for all installations, as noted in Technical Notes 5 and 6 above. IMPORTANT: Even though ACM3P ac ammeters can be used in 480V current monitoring applications, the ac supply connected to TB1 must never exceed the maximum rating of 264V/47-63Hz. PANEL INSTALLATION PANEL 2-56 Hex Nuts (4 places) Tighten each nut to 15 to 20 ozf-in (0.106 to 0.140 N-m). ACM3P Panel Cutout L1 L2 L3 SIDE VIEW All connections to ACM3P ammeters must be made after the unit is securely attached to the panel, and with all associated load and supply voltages de-energized (off), using extreme caution and observing all safety measures applicable to the user’s installation. Care should be exercised when passing conductors through the ammeter’s built-in current transformers L1, L2, and L3. The installed wire-positions should be such that minimal mechanical forces are applied to the current transformers, TB1, or to the ACM3P ammeter itself. In high-vibration environments, it is strongly recommended that strain reliefs be used for all wiring. Using Figure 1 as a guide, carefully insert the ACM3P assembly into the panel opening. From the rear of the panel, install and then tighten the four #2-56 hex nuts over the threaded studs. Tighten each nut to 15 to 20 ozf-in (0.106 to 0.140 N-m). Use only the factory-supplied hardware as the use of substitute hardware could result in an unsafe installation and/or adversely affect the reliability of the installation. The recommended panel thickness range that can be used with the supplied hardware is 0.040 inches (1.0mm) to 0.25 inches (6.4mm). Panel thicknesses outside of this range may require additional usersupplied hardware or modifications. Figure 1. Panel Installation www.murata-ps.com/support MPM_ACM3P Series.A04 Page 3 of 6 ACM3P Series Three-Phase AC Ammeters TYPICAL WIRING DIAGRAMS PHASE A PHASE B L1 L2 L1 L2 B TB1 A L3 Note: Line and phase currents are the same for Wye systems. Fuse* L3 PHASE C 85–264 Vac 47–63 Hz Figure 2. Wiring diagram Wye systems *See technical note 6. L1 PHASE A L1 L2 PHASE B B L2 TB1 A L3 Fuse* L3 PHASE C 85–264 Vac 47–63 Hz Figure 3. Wiring diagram for Delta systems monitoring line current *See technical note 6. PHASE B L1 L2 L2 B L1 TB1 A L3 PHASE A PHASE C Fuse* L3 85–264 Vac 47–63 Hz Figure 4. Wiring diagram for Delta systems monitoring phase current *See technical note 6. www.murata-ps.com/support MPM_ACM3P Series.A04 Page 4 of 6 ACM3P Series Three-Phase AC Ammeters PANEL CUTOUT RECOMMENDED DRILL AND PANEL CUTOUT DIMENSIONS INTERNAL CORNER RADII: 0.032 (0.81) MAX. 1.07 (27.18) The panel opening must be centered vertically and horizontally between the four 0.093 (2.362mm) diameter holes. 0.870 (22.10) 1.426 (36.22) 1.626 (41.30) 0.093 (2.362) DIAMETER (4 REQUIRED) MECHANICAL SPECIFICATIONS 2.10 (53.3) 0.51 (12.95) Dimensions are in inches (mm). 0.12 (3.05) (min) 1.43 (36.3) L1 L2 L3 Tolerances (unless otherwise specified): .XX ± 0.02 (0.51) .XXX ± 0.010 (0.254) Angles ± 2˚ 1.07 (27.20) Side View Components are shown for reference only. SEL MULTI-PHASE AC AMMETER 0.40 (10.16) Front View 0.12 (3.05) (min) L1 Lead Length 5.0 (127) min. 0.22 (5.59) (min) 1.63 (41.4) B TB1 A 0.33 (8.39) (min) L3 Bottom View 0.086 DIA (REF) 2-56 UNC THREAD L2 0.60 (15.24) (max) Back View Diameter: Inner: 0.57 (14.5) Outer: 1.175 (29.8) www.murata-ps.com/support MPM_ACM3P Series.A04 Page 5 of 6 ACM3P Series Three-Phase AC Ammeters 1. Description of safety marks: Caution, risk of electrical shock Caution, risk of danger Equipment is protected throughout by double or reinforced insulation 2. Cleaning Instructions: Gently clean with dry cloth only. 3. Caution: if the equipment is used in a manner not specified by Murata Power Solutions, the protection provided by the equipment may be impaired. NOTES Murata Power Solutions, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A. ISO 9001 and 14001 REGISTERED Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. © 2014 Murata Power Solutions, Inc. www.murata-ps.com/support MPM_ACM3P Series.A04 Page 6 of 6