ACA-20PC-1-AC1-RL-C - Murata Power Solutions

CURRENT LIMITED

AC OR DC SUPPLY

3½ DIGIT

A/D CONVERTER

+V –V

–

RMS-to-DC

CONVERTER

CAL.

BUILT-IN

CURRENT

TRANSFORMER

LED DISPLAY

POWER

CONVERTER

TB1

A B

(L1)

MEASURED AC

LOAD CURRENT

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SIMPLIFIED SCHEMATIC DIAGRAM

Figure 1. ACA-20PC Series simpliﬁ ed schematic

Now

Available with

Wire Lead CTs

ACA-20PC Series

Digital, LED-Display AC Ammeters with

Built-in Current Transformers

MPM_ACA_20PC.C01 Page 1 of 6

FEATURES

 Built-in Current Transformers for direct measurement

of 0 to 2/20/50/100 Amps

 Functionally complete:

On-board current transformers

Scaling/interface circuitry

Precision A/D converters

Bright red LED displays

 8 different models

 Subminiature, 1.38" x 0.88" package

 Easy-to-read, 0.37"/9.4mm digits

 AC powered models 85-264Vac @ 50/60Hz

 "Self-powered" 85-264Vac, 2A and 20A models feature

built-in load connections

 +5-40V dc powered models

 2000V isolation; approvals to UL/cUL/IEC/61010-1

Murata Power Solutions' new ACA-20PC Series are the ﬁ rst digital ac ammeters to incorporate

on-board current transformers (CT’s), and they are amazingly easy to use. Simply pass the

current-carrying load wire through the ACA-20PC’s on-board CT, apply power to the meter's

two supply terminals, and you’re instantly measuring ac currents over one of four ranges (0-2A

with 1mA resolution, 0-20A with 10mA resolution, or 0-50A and 0-100A with 100mA resolu-

tion). Absolutely no external components, such as expensive low-value shunts or 5A "donut"

CT’s, are required.

Meters are ac powered (120/220Vac @ 50/60Hz) or dc powered (+5-40V) and impose

minimal loads (50mA max. and 120mA max., respectively) on their supplies. All models employ

auto-zeroing circuits, precision bandgap references, and super stable thin-ﬁ lm resistors for

unsurpassed accuracy (±0.15%FS) and stability.

The functionally complete ACA-20PC ammeters provide all the scaling/interface circuitry to

mate the CT’s output to a precision (3½ digit) A/D converter. The A/D's output goes directly to

drivers for the meters’ large (0.37"/9.4mm digit height), easy-to-read, LED displays. AC-pow-

ered units have on-board AC/DC converters, and wide-range dc-powered units have on-board

linear regulators. AC-powered models can be powered by the same ac supply whose current

they are monitoring. The 2A and 20A, 85-264Vac, 50/60Hz ("AC1") models feature additional

on-board terminal blocks to supply power to the external load. All models provide 2000Vdc iso-

lation between the measured ac current and their power supply, and all are UL/CSA recognized.

Each meter is housed in a subminiature, 1.38" x 0.88", epoxy-encapsulated package. Total

behind-the-panel installation depth is approximately 2 inches.

US E156931

➀ The ACA-20PC-1-AC1-RL and ACA-20PC-2-AC1-RL have 4-position on-board

terminal blocks. All other models have 2-position terminal blocks.

➁ Speciﬁ ed full-scale currents are those passing through the built-in CT's

primary(load) circuit, over the frequency of 45-450Hz. The Overcurrent Rating

is a continuous rating that applies to the measured ac load current. It does

not apply to any circuitry external to the meter. Accuracy is guaranteed to the

rated current.

➁ For the ACA-20PC-2-AC1-RL, if the load is connected to the meter's on-board

4-position terminal block, the 20A full scale range requires 12AWG solid

copper wire on all connections. If 14AWG solid copper wire is used, the current

should be limited to 15A. See Figure 3.

➃ All speciﬁ ed maximum power supply currents are steady-state values.

AC-powered models can draw higher surges at initial turn-on.

➄ Maximum reverse polarity protection on "DC1" models is –40Vdc.

Full-Scale Current (45-450Hz) ➁Min. Typ. Max. Units

ACA-20PC-1-XXX-XX – – 1.999 Amps

ACA-20PC-2-XXX-XX ➂– – 19.99 Amps

ACA-20PC-3-XXX-XX – – 50.0 Amps

ACA-20PC-4-XXX-XX – – 100.0 Amps

DMS-30798-C – – 30.0 Amps

Overcurrent Rating ➁1.5 x rated full-scale current

Performance

Sampling Rate 2.5 reading per second

Accuracy ➁±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 (Vin = 0 Volts) “–001” “000” “001” Counts

Dielectric Withstanding Voltage 2000 – – Vdc

UL/IEC61010-1 Measurement category II

Power Supply Voltage ➄

ACA-20PC-X-AC1-RL (47-99Hz) 85 120 264 Vac

ACA-20PC-X-DC1-RL +4.75 – +40 Vdc

Power Supply Current ➃

ACA-20PC-X-AC1-RL (47-99Hz) – 30 50 mA

ACA-20PC-X-DC1-RL – +8 +12 mAdc

Power Supply Terminal Block

ACA-20PC-1-AC1-RL and ACA-20PC-2-AC1-RL

(2A and 20A ac-powered models with 4-position terminal blocks):

Wire Size and Type 12-20AWG (solid), 14-20AWG (stranded)

Insulation Strip Length 0.25 inches

Screw Tightening Torque 4.4 lb·in (0.5N·m) ±20%

Maximum Rated Current 20A with 12AWG solid wire; 15A with

14AWG solid or stranded wire

Maximum Rated Voltage 630V (VDE 0110-V. Group 2)

250V (VDE 0110-V Group 3)

ACA-20PC-X-XXX-XX

(All other ac or dc-powered models with 2-position terminal blocks):

Wire Size and Type 16-24AWG (solid or stranded)

Insulation Strip Length 0.25 inches

Screw Tightening Torque 2.2 lb·in (0.25 N·m) ±20%

Display

Display Type and Size 3½ digit, 0.37"/9.4mm high LED

Overrange Indication “1_ _ _”

Decimal Point Fixed, model dependent

Physical/Environmental

Operating Temperature 0 – +60 °C

Storage Temperature –40 – +75 °C

Humidity (non-condensing) 0 – 95 %

Physical/Environmental

Case Material Polycarbonate

Dimensions 1.38”W x 0.88”H. Depth is model depen-

dent (see mechanical speciﬁ cation)

Weight:

ACA-20PC-1-XXX-XX 1.1 ounces (31 grams)

ACA-20PC-2-XXX-XX 1.1 ounces (31 grams)

ACA-20PC-3-XXX-XX 1.3 ounces (37 grams)

ACA-20PC-4-XXX-XX 1.5 ounces (43 grams)

DMS-30798-C 1.0 ounces (28 grams)

Performance/Functional Speciﬁ cations

Typical at TA = +25°C, unless otherwise noted. ➀

ACA - 20PC - 1 - AC1 - RL - L - C

1 = 1.999A

2 = 19.99A

3 = 50.0A

4 = 100.0A

RL = Red Standard

BL = Blue Standard

PGL = Green Standard

AC1 = 85-264Vac@50/60Hz

DC1 = +5-40Vdc

DMS-30798-C: 30Amp model with a wire lead CT and “-AC1”

power supply speciﬁ cations. See Mechanical section for dimensions.

Accessories: DMS-20-CP Panel cutout punch

A DMS-BZL4-C bezel assembly with sealing gasket is supplied with each ammeter.

Input Range:

LED Color:

Power Supply:

(45-450Hz)

Ordering Information

Leaded CT (100A model)

RoHS

See www.murata-ps.com/dpm-availability for model-speciﬁ c availability.

www.murata-ps.com/support

ACA-20PC Series

Digital, LED-Display AC Ammeters with

Built-in Current Transformers

MPM_ACA_20PC.C01 Page 2 of 6

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ACA-20PC Series

Digital, LED-Display AC Ammeters with

Built-in Current Transformers

MPM_ACA_20PC.C01 Page 3 of 6

IMPORTANT! To ensure safe and reliable operation, ACA-20PC

ammeters must be installed and serviced by qualiﬁ ed technical

personnel. Contact Murata Power Solutions if there is any doubt

regarding ammeter installation and/or operation.

1. Measurement Type: ACA-20PC ac ammeters employ a full-wave-

rectiﬁ ed, average responding, rms-calibrated circuit to measure the

stepped-down output of their on-board, L1 current transformer (CT) .

Stated accuracy speciﬁ cations are measured using a sine-wave cur-

rent at or close to the speciﬁ ed full scale input level, at nominal line

frequency.

2. Calibration: Periodic recalibration of ACA-20PC ammeters is not

required under normal, indoor operating environments. If user

calibration is necessary, it should be performed by qualiﬁ ed technical

personnel. Calibration is performed with potentially lethal voltages

applied to the ACA-20PC and its associated wiring, with the speciﬁ ed

full-scale current ﬂ owing 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 Speciﬁ cations). Contact Murata Power Solutions if

additional information is required regarding calibration, setup, or any

other technical issue pertaining to the ACA-20PC.

3. Wire Gauges and Fusing: Wires speciﬁ ed in the Functional Speciﬁ -

cations section must be used for making connections to ACA-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 speciﬁ c installation.

ACA-20PC Series ammeters are not internally fused. Special attention

must be paid to ACA-20PC-1-AC1 (0-2A range) and ACA-20PC-2-AC1

(0-20A range) ac-powered models when their built-in auxiliary termi-

nal block connections on TB1 are used to supply power to an external

load. The input supply wires connected to both the ammeter and the

load must be fused according to the current rating of the wire gauge

being used, in accordance with applicable regulatory codes, but not

to exceed TB1’s maximum 20A rating. If TB1 is not used to supply

power to external loads, a 0.25A/250V time delay/time lag fuse must

be used.

ACA-20PC-3-AC1 (0-50A range, ac-powered) and ACA-20PC- 4-AC1

(0-100A, ac-powered) models’ 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 models must be

fused with a 0.25A 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 ac supply inputs,

TB1-A and TB1-B, on ac-powered ammeters are not in themselves

polarity sensitive, that is, they have no internal "AC LO" or "AC HI"

TECHNICAL NOTES designations. Also, ac-powered ACA-20PC ammeters do not include

or require a connection to earth/chassis ground. However, in many

applications, external ac loads which are connected directly to the

ACA-20PC’s built-in auxiliary terminal blocks must be wired with

proper polarity and connected to earth/chassis ground.

5. Connector Torque Ratings: It is important to tighten TB1's screw

terminals to their rated torque speciﬁ cations of 4.4 pound-inches

(0.5Nm) for four-terminal ammeters (ACA-20PC-1-AC1-RL and ACA-

20PC-2-AC1-RL), and 3.6 pound-inches (0.4Nm) for two-terminal

ammeters. Proper tightening will minimize connector losses and

ensure safe, reliable operation.

6. 100 Amp Model (ACA-20PC-4-XXX): This model’s built-in current

transformer requires a larger panel cutout width dimension. See

Mechanical Speciﬁ cations for more information.

7. DC-Powered Models: DC-powered models draw minimal supply

currents 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.

8. 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. Of

course, this isolation rating only applies to applications in which the

load wiring (i.e., the wire passing through the CT’s center hole) does

not connect directly or indirectly to TB1-A or TB1-B.

All connections to ACA-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 the load-carrying conduc-

tor through the meter’s built-in CT— particularly when larger-gauge

conductors are used. The position of the installed wire should be

such that minimal forces are applied to the built-in CT, TB1, or to

the ammeter itself. In high-vibration environments, adequate strain

reliefs be used for all load and supply wiring.

To ensure a secure panel-mount installation, Murata Power Solutions

recommends using the DMS-BZL4 bezel assembly (with sealing

gasket) supplied with each ammeter. Also, please note that the ACA-

20PC-4-XXX 100A oversize CT requires a larger panel-cutout width

of 1.350" (34.3mm). See Mechanical Speciﬁ cations for detailed

cutout and ammeter dimensions.

Following the four-step sequence shown in Figure 2 below—being

careful not to apply excessive force or twisting motions— insert the

ammeter into the panel opening. When using the DMS-BZL4 bezel

assembly, install its sealing gasket so it is positioned between the

ammeter’s front ﬂ ange and panel front surface (see Mechanical

Speciﬁ cations). Be sure to use and securely tighten all four screws

supplied with the bezel assembly.

PANEL INSTALLATION

First pass and carefully dress one external load wire through the

on-board CT (L1). Then connect the ac supply and load wires 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 one load wire through the on-board CT’s center hole.

Figure 3. 2A and 20A, 85-264V AC-Powered Models

With Auxilliary Load Connections

Figure 5. All DC-Powered Models

Figure 4. All Other AC-Powered Models

FUSED

85-264Vac

POWER

85-264Vac TO LOAD

FUSED

85-264Vac

POWER

TO LOAD

FUSED

AC POWER

SUPPLY

TO AC LOAD

AC SUPPLY

–

FUSED

DC POWER

SUPPLY

TO AC LOAD

AC SUPPLY

–

ACA-20PC-X-ACX

ACA-20PC-X-DCX

ACA-20PC-2-AC1-RL

ACA-20PC-1-AC1-RL

Step 2. Step 3. Step 4.Step 1.

Figure 2. Panel Installation

Panel

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ACA-20PC Series

Digital, LED-Display AC Ammeters with

Built-in Current Transformers

MPM_ACA_20PC.C01 Page 4 of 6

TYPICAL WIRING DIAGRAM

ACA-20PC-1 & 2-AC1-RL

ACA-20PC-3 Series

Mechanical Dimensions: Inches (mm) Tolerances: 2 PL DEC ±0.02 (±0.51), 3 PL DEC ±0.010 (±0.254)

ACA-20PC-4 Series

2A and 20A, 85-264V ac-powered models

ACA-20PC-1 & 2

2A and 20A, all other models

50A models 100A models with pc-board mounted CTs

1.00

(25.4)

2.01

(51.1)

1.30

(33.0)

1.38

(35.1)

0.040

(1.02) 0.80

(20.3)

0.88

(22.4)

1.32

(33.5)

0.040

(1.02)

0.040

(1.02)

CAL.

FRONT VIEW BACK VIEW

Hole Diameter:

0.27 (6.9) min.

1.00

(25.4)

2.01

(51.1)

1.30

(33.0)

1.38

(35.1)

0.040

(1.02) 0.80

(20.3)

0.88

(22.4)

1.32

(33.5)

0.040

(1.02)

0.040

(1.02)

CAL.

FRONT VIEW BACK VIEW

Hole Diameter:

0.27 (6.9) min.

1.00

(25.4)

2.12

(53.8)

1.30

(33.0)

1.38

(35.1)

0.040

(1.02) 0.80

(20.3)

0.88

(22.4)

1.54

(39.1)

0.040

(1.02)

0.040

(1.02)

CAL.

FRONT VIEW BACK VIEW

Hole Diameter:

0.35 (8.9) min.

1.00

(25.4)

2.53

(64.3)

1.30

(33.0)

1.38

(35.1)

0.040

(1.02) 0.80

(20.3)

0.88

(22.4)

1.32

(33.5)

0.040

(1.02)

0.040

(1.02)

CAL.

FRONT VIEW BACK VIEW

THIS MODEL REQUIRES A PANEL

CUTOUT WIDTH OF 1.350" (34.3MM)

1.33

(33.8)

Hole Diameter:

0.55 (14.0) min.

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ACA-20PC Series

Digital, LED-Display AC Ammeters with

Built-in Current Transformers

MPM_ACA_20PC.C01 Page 5 of 6

MECHANICAL SPECIFICATIONS

* 1.350 (34.3) for ACA-20PC-4-XXX 100A model

with pc-board mounted CTs.

BEZEL

Gasket

#2-56 INSERT

0.156 (3.96) DEEP

FRONT VIEW 1.280

(32.51)

0.187

(4.75)

1.826 (46.38)

0.838

(21.29)

1.626 (41.30)

1.07

(27.18)

INTERNAL CORNER RADII:

0.032 (0.81) MAX.

0.093 (2.362) DIA

(4 REQUIRED)

0.116 (2.95)

1.336 (33.93)* 0.145 (3.68)

PANEL CUTOUT

BEZEL INSTALLATION AND RECOMMENDED DRILL AND

PANEL CUTOUT

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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. Speciﬁ cations are subject to change without

Murata Power Solutions, Inc.

11 Cabot Boulevard, Mansﬁ eld, MA 02048-1151 U.S.A.

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/

ACA-20PC Series

Digital, LED-Display AC Ammeters with

Built-in Current Transformers

MPM_ACA_20PC.C01 Page 6 of 6

ACA-20PC-4-XXX-L (100A model)

DMS-30798-C (30A model)

MECHANICAL SPECIFICATIONS, CONTINUED

1.00

(25.4)

1.30

(33.0)

1.38

(35.1)

0.040

(1.02) 0.80

(20.3)

0.88

(22.4)

1.14

(29.0)

0.040

(1.02)

0.040

(1.02)

CAL.

FRONT VIEW BACK VIEW

Lead Length:

2.0 (50.5) min.

ID: 100A Model: 0.58 (14.7)

DMS-30798-C (30A): 0.35 (8.9)

OD: 100A Model: 1.18 (30.0)

DMS-30798-C (30A): 0.87 (22.0)

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 speciﬁ ed by Murata Power Solutions, the protection provided by the equipment may be impaired.

Mouser Electronics

Authorized Distributor

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ACA-20PC-4-AC1-RL ACA-20PC-4-DC1-RL ACA-20PC-3-DC1-RL ACA-20PC-3-AC1-RL ACA-20PC-1-AC1-RL-C

ACA-20PC-1-DC1-RL-C ACA-20PC-2-AC1-RL-C ACA-20PC-2-DC1-RL-C ACA-20PC-3-AC1-RL-C ACA-20PC-3-

DC1-RL-C ACA-20PC-4-AC1-RL-C ACA-20PC-4-DC1-RL-C DMS-30798-C ACA-20PC-1-AC1-RL ACA-20PC-2-AC1-

RL ACA-20PC-2-DC1-RL ACA-20PC-1-DC1-RL ACA-20PC-4-AC1-RL-L-C ACA-20PC-2-AC2-RL