ACA5-20PC Series www.murata-ps.com 5 Amp Input LED-Display AC Ammeters C US E156931 ® FEATURES ACA5-20PC Series AC Ammeters are designed to scale and digitally display the output of „„ standard, 5A-output current transformers (50:5A, 500:5A, 1000:5A, etc.). Simply pass the Scales and displays the output of 50:5A to 2000:5A current transformers secondary/output wires of the "primary" CT through the ACA5-20PC's on-board CT, apply power to the meter, and you're instantly measuring ac currents over one of 14 ranges from „„ 14 ranges (0-50 Amp to 0-2000 Amp) 0-50A (with 100mA resolution) to 0-2000A (with 1A resolution). Because they accept out- „„ 2 Power options, 28 models puts from previously installed high-current CT's, ACA5-20PC's can instantly bring modern „„ Functionally complete: digital precision to older ac ammeters. On-board 5A current transformers The functionally complete ACA5-20PC ammeters incorporate scaling/interface circuitry Scaling/interface circuitry to mate the on-board CT to a precision (3½ digit) A/D converter. The A/D's output directly Precision A/D converters drives the meters' large (0.37"/9.4mm digit height), easy-to-read, LED displays. All models Bright red or green LED displays employ auto-zero circuits, precision bandgap references, and super stable metal-film resis- „„ Subminiature, 1.38" x 0.88" package tors for unsurpassed accuracy (±0.15%FS) and stability. „„ Easy-to-read, 0.37"/9.4mm digits ACA5-20PC meters are either ac (120/220Vac @ 50/60Hz) or dc (+5-40V) powered. „„ AC powered models: 120/220Vac @ 50/60Hz AC models can be powered by the same ac supply whose current they are monitoring. All ACA5-20PCs provide 2000Vdc isolation between the measured ac current and their power „„ AC models can be "self-powered" supply, and all models are UL/CSA recognized. „„ +5-40V dc powered model Each meter is housed in a subminiature, 1.38" x 0.88", epoxy-encapsulated package „„ 2000V isolation; approvals to UL/cUL/IEC/61010-1 whose behind-the-panel installation depth is 2 inches. Display color options include stan- „„ Digital replacements for analog ammeters dard red, high-intensity red, and standard green. Each meter is supplied with a plastic bezel assembly with sealing gaskets (MPS DMS-BZL4-C). SIMPLIFIED SCHEMATIC DRAWING For full details go to www.murata-ps.com/rohs CURRENT LIMITED AC OR DC SUPPLY www.murata-ps.com/support MPM_ACA5-20PC.C02 Page 1 of 5 ACA5-20PC Series 5 Amp Input LED-Display AC Ammeters Performance/Functional Specifications Ordering Information Typical at TA = + 25°C, unless otherwise noted. ACA5 - 20PC - 1 - AC1 - RL - C Full-Scale Current (A) (B) Min. Typ. Max. Units All Models – – 5.0 Amps Add -C for RoHS Input Range: Overcurrent Rating (A) 1.5 x rated full-scale current (45-450Hz) 1 = 50.0A LED Color: Performance RL = Red Standard 2 = 75.0A Sampling Rate 2.5 reading per second 3 = 100.0A Accuracy (B) ±0.15%FS ±6 Counts 4 = 150.0A Power Supply: Measurement Type Sine wave input, full-wave averaging, 5 = 199.9A AC1 = 85-264Vac@50/60Hz rms calibrated 6 = 250A DC1 = +5-40Vdc Temperature Drift (0 = +60°C) – ±0.2 ±0.4 Cnts/°C 7 = 300A 8 = 400A Zero Reading “–001” “000” “001” Counts 9 = 500A Dielectric Withstanding Voltage 2000 – – Vdc 10 = 600A UL/IEC61010-1 Measurement category II 11 = 750A Power Supply Voltage (C) 12 = 1000A 13 = 1500A ACA-20PC-X-AC1-RL (47-99Hz) 85 120 264 Vac 14 = 1999A ACA-20PC-X-DC1-RL +4.75 – +40 Vdc Power Supply Current (D) See www.murata-ps.com/dpm-availability for model-specific availability. ACA-20PC-X-AC1-RL (47-99Hz) – 30 50 mA A DMS-BZL4 bezel assembly with sealing gasket is supplied with each ACA-20PC-X-DC1-RL – +8 +12 mAdc ammeter. Power Supply Terminal Block TECHNICAL NOTES Wire Size and Type 16-22AWG (solid or stranded) Insulation Strip Length 0.25 inches IMPORTANT! To ensure safe and reliable operation, ACA5-20PC Screw Tightening Torque 3.6 pounds/inches (0.4Nm) ammeters must be installed and serviced by qualified technical per- sonnel. Contact Murata Power Solutions if there is any doubt regarding Display ammeter installation and/or operation. Display Type and Size 3½ digit, 0.37"/9.4mm high LED 1. Measurement Type: ACA5-20PC ac ammeters employ a full-wave- Overrange Indication “1_ _ _” rectified, average responding, rms-calibrated circuit to measure the Decimal Point Model dependent. See Ordering Info. stepped-down output of their built-in L1 current transformer (CT) . Physical/Environmental Stated accuracy specifications are measured using a sine-wave cur- Operating Temperature 0 – +60 °C rent at or close to the full-scale input level, at nominal line frequency. Storage Temperature –40 – +75 °C 2. Calibration: Periodic recalibration of ACA5-20PC ammeters is not required under normal, indoor operating environments. If user calibra- Humidity (non-condensing) 0 – 95 % tion is necessary, it should be performed by qualified technical personnel. Case Material Polycarbonate Calibration is performed with potentially lethal voltages applied to the Dimensions 1.38”W x 0.88”H. Depth is model depen- ACA5-20PC and its associated wiring, with the specified full-scale dent (see mechanical specification) current flowing through the ammeter’s built-in current transformer. Weight: (All models) 1.27 Ounces (36 grams) typical A plastic, fully-insulated adjusting tool must be used to access the recessed calibration potentiometer located on the back of the meter (see Mechanical Specifications). Contact MPS if additional information (A) The specified Full-Scale Current is the current carried by the single wire passing through the center hole of the ACA5-20PC's on-board CT. It is not the load current ultimately being is required regarding calibration, setup, or any other technical issue measured. the Overcurrent Rating is a continuous rating that applies to the Full-Scale pertaining to ACA5-20PC ammeters. Current. It does not apply to any circuitry external to the meter. 3. Wire Gauges and Fusing: Wires specified in the Functional Specifica- (B) Listed accuracy specifications apply over the range of the Rated Full-Scale Current over frequencies of 45-450Hz. tions section must be used for making connections to ACA5-20PC (C) Maximum reverse polarity protection on "DC1" models is –40Vdc. Series ammeters. All power-supply and load wiring must be rated for (D) All specified maximum power supply currents are steady-state. AC-powered models can the supply voltages and currents they will conduct and must comply draw larger surges at initial turn on. with any code or application-mandated requirements pertaining to the user’s specific installation. www.murata-ps.com/support MPM_ACA5-20PC.C02 Page 2 of 5 ACA5-20PC Series 5 Amp Input LED-Display AC Ammeters ACA5-20PC series ammeters are not internally fused. Terminal block ing one of the external 5A CT’s output leads to earth/chassis ground. TB1 is to be used only for powering the ammeters’ internal circuitry; In the USA, consult the latest revision of the National Electrical Code it must not be used to supply power to external loads. The supply (NEC) for more information regarding CT grounding. wires feeding these ammeters must be fused with a 0.25A/250V time After all mechanical assembly is completed, connect the two output delay/time lag fuse, in accordance with applicable regulatory codes. leads of the external 5A CT to each other after they are run through Wire insulation must be stripped to within ±10% of the stated dimen- L1’s center hole. Pressure-style connectors (commonly refered to sions, and wires should be inserted into TB1 such that their insulation as “wire nuts”) are acceptable as long as they are rated for the is not pinched by the screw terminal. number of conductors and voltage invloved. 4. AC Supply Polarity and Grounding: The two supply inputs, TB1-A 10. Replacing Analog Panel Meters: ACA5-20PC ammeters can be and TB1-B, on all ac-powered ACA5-20PC ammeters are not in used as direct replacements for analog panel meters driven by themselves polarity sensitive, that is, they have no internal "AC LO" 5A CT’s. All wiring operations must be performed with both the or "AC HI" designations. Also, ac-powered ACA5-20PC ammeters do load and the supply power sources completely de-energized. not include or require a connection to earth/chassis ground. 5. Connector Torque Ratings: It is important to tighten TB1's, screw- terminals to their rated torque specification of 3.6 pound-inches (0.4Nm). Proper tightening will minimize connector losses and ensure safe, reliable operation. 6. DC-Powered Models: DC-powered models draw minimal supply cur- PANEL INSTALLATION rents (120mA max.) and in most applications can be fused according All connections to ACA5-20PC Series ammeters must be made after the to the supply wire’s maximum amperage rating. However, be sure to ammeter is securely attached to the panel and with all load and supply check and comply with all applicable codes and regulations to ensure voltages de-energized (off). proper installation and operation. Care should be exercised when passing conductors through the ammeter’s 7. Isolation: The on-board CT (L1) provides a minimum 2000Vdc built-in CT. The installed wire positions should be such that minimal isolation between the current-carrying conductor passing through its forces are applied to the built-in CT, TB1, or to the ammeter itself. In primary circuit and the ammeter supply voltage connected to TB1. high-vibration environments, proper strain reliefs must be used for all This isolation rating only applies to applications in which the load load and supply wiring. wiring (i.e., the wire passing through L1’s center hole) does not con- nect directly or indirectly to TB1-A or TB1-B. To ensure a secure panel-mount installation, MPS recommends using the DMS-BZL4-C bezel assembly (with sealing gasket) supplied with each 8. CT Precautions: In normal operation, a 5A current transformer’s ammeter. See Mechanical Specifications for detailed cutout and ammeter secondary circuit operates at a very low voltage due to its closed- dimensions. loop operation and its low burden resistance. However, a CT can still generate potentially lethal voltages if its output current is suddenly Following the four-step sequence shown in Figure 2 — being careful not interrupted. For example, loose CT secondary connections can cause to apply excessive force or twisting motions — insert the ammeter into a condition referred to as “inductive kick". Inductive kick can generate the panel opening. When using the DMS-BZL4-C, install its sealing gas- extremely high voltages across intermitent secondary connections. ket so it is positioned between the ammeter’s front flange and panel front surface (see Mechanical Specifications). Be sure to use and securely Therefore, implementing connections to any 5A current transformer’s tighten all four screws supplied with the bezel assembly. output leads must only be performed with zero load-current, that is, with no power applied to the load circuit. 9. CT Connections and Grounding: Some applications require connect- Step 1. Step 2. Step 3. Step 4.         Figure 2. Panel Installation www.murata-ps.com/support MPM_ACA5-20PC.C02 Page 3 of 5 ACA5-20PC Series 5 Amp Input LED-Display AC Ammeters TYPICAL WIRING DIAGRAMS First pass and carefully dress one output wire from the external CT through the on-board CT (L1). Then connect the ac supply to TB1 as shown. If required, verify that correct line-power polarities are FUSED AC POWER SUPPLY applied to the external load (see Technical Note 4). Ensure all wires are stripped and terminals torqued correctly. For proper operation, pass only a single wire through the on-board CT's center hole. Figure 3. ACA5-20PC AC-Powered Models First pass and carefully dress one output wire from the external CT through the on-board CT (L1). Then connect the two dc power- supply wires to TB1, observing correct positive ("+") and negative FUSED DC POWER SUPPLY ("–") polarities. Ensure all wires are stripped and terminals torqued correctly. For proper operation, pass only a single wire through the on-board CT's center hole. Figure 4. ACA5-20PC DC-Powered Models www.murata-ps.com/support MPM_ACA5-20PC.C02 Page 4 of 5 ACA5-20PC Series 5 Amp Input LED-Display AC Ammeters MECHANICAL SPECIFICATIONS Tolerances inches (mm): 2 PL DEC ±0.02 (±0.51), 3 PL DEC ±0.010 (±0.254) BEZEL INSTALLATION AND RECOMMENDED DRILL AND PANEL CUTOUT        ­ 
        € ‚        DMS-BZL4-C BEZEL      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. This product is subject to the following operating requirements Murata Power Solutions, Inc. and the Life and Safety Critical Application Sales Policy: ISO 9001 and 14001 REGISTERED Refer to: http://www.murata-ps.com/requirements/ 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. © 2018 Murata Power Solutions, Inc. www.murata-ps.com/support MPM_ACA5-20PC.C02 Page 5 of 5