CURRENT LIMITED
AC OR DC SUPPLY
SIMPLIFIED SCHEMATIC DRAWING
C
®US
E156931
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ACA5-20PC Series
5 Amp Input LED-Display AC Ammeters
MPM_ACA5-20PC.C02 Page 1 of 5
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
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
0-50A (with 100mA resolution) to 0-2000A (with 1A resolution). Because they accept out-
puts from previously installed high-current CT's, ACA5-20PC's can instantly bring modern
digital precision to older ac ammeters.
The functionally complete ACA5-20PC ammeters incorporate scaling/interface circuitry
to mate the on-board CT to a precision (3½ digit) A/D converter. The A/D's output directly
drives the meters' large (0.37"/9.4mm digit height), easy-to-read, LED displays. All models
employ auto-zero circuits, precision bandgap references, and super stable metal-film resis-
tors for unsurpassed accuracy (±0.15%FS) and stability.
ACA5-20PC meters are either ac (120/220Vac @ 50/60Hz) or dc (+5-40V) powered.
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
supply, and all models are UL/CSA recognized.
Each meter is housed in a subminiature, 1.38" x 0.88", epoxy-encapsulated package
whose behind-the-panel installation depth is 2 inches. Display color options include stan-
dard red, high-intensity red, and standard green. Each meter is supplied with a plastic bezel
assembly with sealing gaskets (MPS DMS-BZL4-C).
FEATURES
Scales and displays the output of 50:5A to 2000:5A
current transformers
14 ranges (0-50 Amp to 0-2000 Amp)
2 Power options, 28 models
Functionally complete:
On-board 5A current transformers
Scaling/interface circuitry
Precision A/D converters
Bright red or green LED displays
Subminiature, 1.38" x 0.88" package
Easy-to-read, 0.37"/9.4mm digits
AC powered models: 120/220Vac @ 50/60Hz
AC models can be "self-powered"
+5-40V dc powered model
2000V isolation; approvals to UL/cUL/IEC/61010-1
Digital replacements for analog ammeters
Performance/Functional Specifications
Typical at TA = + 25°C, unless otherwise noted.
(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
measured. the Overcurrent Rating is a continuous rating that applies to the Full-Scale
Current. It does not apply to any circuitry external to the meter.
(B) Listed accuracy specifications apply over the range of the Rated Full-Scale Current over
frequencies of 45-450Hz.
(C) Maximum reverse polarity protection on "DC1" models is –40Vdc.
(D) All specified maximum power supply currents are steady-state. AC-powered models can
draw larger surges at initial turn on.
ACA5 - 20PC - 1 - AC1 - RL - C
1 = 50.0A
2 = 75.0A
3 = 100.0A
4 = 150.0A
5 = 199.9A
6 = 250A
7 = 300A
8 = 400A
9 = 500A
10 = 600A
11 = 750A
12 = 1000A
13 = 1500A
14 = 1999A
RL = Red Standard
AC1 = 85-264Vac@50/60Hz
DC1 = +5-40Vdc
Input Range:
(45-450Hz)
LED Color:
Power Supply:
A DMS-BZL4 bezel assembly with sealing gasket is supplied with each
ammeter.
Ordering Information
Add -C for RoHS
Full-Scale Current (A) (B) Min. Typ. Max. Units
All Models – – 5.0 Amps
Overcurrent Rating (A) 1.5 x rated full-scale current
Performance
Sampling Rate 2.5 reading per second
Accuracy (B) ±0.15%FS ±6 Counts
Measurement Type Sine wave input, full-wave averaging,
rms calibrated
Temperature Drift (0 = +60°C) – ±0.2 ±0.4 Cnts/°C
Zero Reading “–001” “000” “001” Counts
Dielectric Withstanding Voltage 2000 – – Vdc
UL/IEC61010-1 Measurement category II
Power Supply Voltage (C)
ACA-20PC-X-AC1-RL (47-99Hz) 85 120 264 Vac
ACA-20PC-X-DC1-RL +4.75 – +40 Vdc
Power Supply Current (D)
ACA-20PC-X-AC1-RL (47-99Hz) – 30 50 mA
ACA-20PC-X-DC1-RL – +8 +12 mAdc
Power Supply Terminal Block
Wire Size and Type 16-22AWG (solid or stranded)
Insulation Strip Length 0.25 inches
Screw Tightening Torque 3.6 pounds/inches (0.4Nm)
Display
Display Type and Size 3½ digit, 0.37"/9.4mm high LED
Overrange Indication “1_ _ _”
Decimal Point Model dependent. See Ordering Info.
Physical/Environmental
Operating Temperature 0 – +60 °C
Storage Temperature –40 – +75 °C
Humidity (non-condensing) 0 – 95 %
Case Material Polycarbonate
Dimensions 1.38”W x 0.88”H. Depth is model depen-
dent (see mechanical specification)
Weight: (All models) 1.27 Ounces (36 grams) typical
See www.murata-ps.com/dpm-availability for model-specific availability.
www.murata-ps.com/support
ACA5-20PC Series
5 Amp Input LED-Display AC Ammeters
MPM_ACA5-20PC.C02 Page 2 of 5
IMPORTANT! To ensure safe and reliable operation, ACA5-20PC
ammeters must be installed and serviced by qualified technical per-
sonnel. Contact Murata Power Solutions if there is any doubt regarding
ammeter installation and/or operation.
1. Measurement Type: ACA5-20PC ac ammeters employ a full-wave-
rectified, average responding, rms-calibrated circuit to measure the
stepped-down output of their built-in L1 current transformer (CT) .
Stated accuracy specifications are measured using a sine-wave cur-
rent at or close to the full-scale input level, at nominal line frequency.
2. Calibration: Periodic recalibration of ACA5-20PC ammeters is not
required under normal, indoor operating environments. If user calibra-
tion is necessary, it should be performed by qualified technical personnel.
Calibration is performed with potentially lethal voltages applied to the
ACA5-20PC and its associated wiring, with the specified full-scale
current flowing through the ammeter’s built-in current transformer.
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
is required regarding calibration, setup, or any other technical issue
pertaining to ACA5-20PC ammeters.
3. Wire Gauges and Fusing: Wires specified in the Functional Specifica-
tions section must be used for making connections to ACA5-20PC
Series ammeters. All power-supply and load wiring must be rated for
the supply voltages and currents they will conduct and must comply
with any code or application-mandated requirements pertaining to the
user’s specific installation.
TECHNICAL NOTES
ACA5-20PC series ammeters are not internally fused. Terminal block
TB1 is to be used only for powering the ammeters’ internal circuitry;
it must not be used to supply power to external loads. The supply
wires feeding these ammeters must be fused with a 0.25A/250V time
delay/time lag fuse, in accordance with applicable regulatory codes.
Wire insulation must be stripped to within ±10% of the stated dimen-
sions, and wires should be inserted into TB1 such that their insulation
is not pinched by the screw terminal.
4. AC Supply Polarity and Grounding: The two supply inputs, TB1-A
and TB1-B, on all ac-powered ACA5-20PC ammeters are not in
themselves polarity sensitive, that is, they have no internal "AC LO"
or "AC HI" designations. Also, ac-powered ACA5-20PC ammeters do
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-
rents (120mA max.) and in most applications can be fused according
to the supply wire’s maximum amperage rating. However, be sure to
check and comply with all applicable codes and regulations to ensure
proper installation and operation.
7. Isolation: The on-board CT (L1) provides a minimum 2000Vdc
isolation between the current-carrying conductor passing through its
primary circuit and the ammeter supply voltage connected to TB1.
This isolation rating only applies to applications in which the load
wiring (i.e., the wire passing through L1’s center hole) does not con-
nect directly or indirectly to TB1-A or TB1-B.
8. CT Precautions: In normal operation, a 5A current transformer’s
secondary circuit operates at a very low voltage due to its closed-
loop operation and its low burden resistance. However, a CT can still
generate potentially lethal voltages if its output current is suddenly
interrupted. For example, loose CT secondary connections can cause
a condition referred to as “inductive kick". Inductive kick can generate
extremely high voltages across intermitent secondary connections.
Therefore, implementing connections to any 5A current transformer’s
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-
ing one of the external 5A CT’s output leads to earth/chassis ground.
In the USA, consult the latest revision of the National Electrical Code
(NEC) for more information regarding CT grounding.
After all mechanical assembly is completed, connect the two output
leads of the external 5A CT to each other after they are run through
L1’s center hole. Pressure-style connectors (commonly refered to
as “wire nuts”) are acceptable as long as they are rated for the
number of conductors and voltage invloved.
10. Replacing Analog Panel Meters: ACA5-20PC ammeters can be
used as direct replacements for analog panel meters driven by
5ACT’s. All wiring operations must be performed with both the
load and the supply power sources completely de-energized.
Figure 2. Panel Installation
All connections to ACA5-20PC Series ammeters must be made after the
ammeter is securely attached to the panel and with all load and supply
voltages de-energized (off).
Care should be exercised when passing conductors through the ammeter’s
built-in CT. The installed wire positions should be such that minimal
forces are applied to the built-in CT, TB1, or to the ammeter itself. In
high-vibration environments, proper strain reliefs must be used for all
load and supply wiring.
To ensure a secure panel-mount installation, MPS recommends using the
DMS-BZL4-C bezel assembly (with sealing gasket) supplied with each
ammeter. See Mechanical Specifications for detailed cutout and ammeter
dimensions.
Following the four-step sequence shown in Figure 2 — being careful not
to apply excessive force or twisting motions — insert the ammeter into
the panel opening. When using the DMS-BZL4-C, install its sealing gas-
ket so it is positioned between the ammeter’s front flange and panel front
surface (see Mechanical Specifications). Be sure to use and securely
tighten all four screws supplied with the bezel assembly.
Step 2. Step 3. Step 4.Step 1.
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ACA5-20PC Series
5 Amp Input LED-Display AC Ammeters
MPM_ACA5-20PC.C02 Page 3 of 5
PANEL INSTALLATION
Figure 4. ACA5-20PC DC-Powered Models
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 ac supply to TB1
as shown. If required, verify that correct line-power polarities are
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.
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
("–") 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.
FUSED AC POWER SUPPLY
FUSED DC POWER SUPPLY
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ACA5-20PC Series
5 Amp Input LED-Display AC Ammeters
MPM_ACA5-20PC.C02 Page 4 of 5
TYPICAL WIRING DIAGRAMS
Tolerances inches (mm):
2 PL DEC ±0.02 (±0.51),
3 PL DEC ±0.010 (±0.254)
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.
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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.
Murata Power Solutions, Inc.
ISO 9001 and 14001 REGISTERED
This product is subject to the following operating requirements
and the Life and Safety Critical Application Sales Policy:
Refer to: http://www.murata-ps.com/requirements/
ACA5-20PC Series
5 Amp Input LED-Display AC Ammeters
MPM_ACA5-20PC.C02 Page 5 of 5
MECHANICAL SPECIFICATIONS
BEZEL INSTALLATION AND RECOMMENDED DRILL AND PANEL CUTOUT
Mouser Electronics
Authorized Distributor
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AC1-RL ACA5-20PC-5-DC1-RL ACA5-20PC-10-AC1-RL ACA5-20PC-4-AC1-RL ACA5-20PC-3-AC1-RL ACA5-
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DC1-RL ACA5-20PC-4-AC2-RL-C ACA5-20PC-8-AC2-RL-C ACA5-20PC-2-AC2-RL-C ACA5-20PC-5-AC2-RL-C
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AC1-RL ACA5-20PC-1-DC1-RL ACA5-20PC-1-AC1-RL ACA5-20PC-10-DC1-RL ACA5-20PC-9-AC1-RL ACA5-
20PC-9-DC1-RL ACA5-20PC-9-AC2-RL-C ACA5-20PC-12-AC2-RL ACA5-20PC-9-AC2-RL
