Datasheet ACA-20PC-4-DC3-RL, ACA-20PC-4-DC3-RH, ACA-20PC-4-DC3-GS, ACA-20PC-4-DC2-RL, ACA-20PC-4-DC1-RL Datasheet (DATEL)

DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: [phone] Fax: [phone] • E–mail: [e-mail] • Internet: www.datel.com

ACA-20PC Series

Digital, LED-Display

AC Ammeters with Built-in

Current Transformers

Figure 1. ACA-20PC Series Simplified Schematic

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 or green LED displays

• 32 different models

• Subminiature, 1.38" x 0.88" package

• Easy-to-read, 0.37"/9.4mm digits

• AC powered models:

85-264Vac @ 50/60Hz
240-310Vac @ 50/60Hz
85-140Vac @ 400Hz

• "Self-powered" 85-264Vac, 2A and 20A

models feature built-in load connections

• DC powered models:

+5V, +5-40V, +36-75V

• 2000V isolation; UL/CSA recognized

AC or DC

INPUT POWER

POWER

CONVERTER

3½ DIGIT

A/D CONVERTER

+V –V

–

+

PRECISION

FULL-WAVE

RECTIFIER

CAL.

LED DISPLAY

BUILT-IN

CURRENT

TRANSFORMER

(L1)

TB1

A B

–+

MEASURED AC

LOAD CURRENT

Order on-line
at www.datel.com

E156931

DATEL's new ACA-20PC Series are the first digital ac ammeters to incorporate on­board 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 resolution). Absolutely no external components, such as expensive low-value
shunts or 5A "donut" CT’s, are required.

Meters are ac powered (120/220/277Vac @ 50/60Hz or 120Vac @ 400Hz) or dc
powered (+5V, +5-40V, or +36-75V) 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-film 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-powered 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 isolation 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. Display color options
include standard red, high-intensity red, and standard green.

2

DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: [phone] Fax: [phone] • E–mail: [e-mail] • Internet: www.datel.com

ACA-20PC Series

3½ DIGIT, LED DISPLAY, AC AMMETERS

Physical/Environmental
Dimensions 1.38"W x 0.88"H Depth is model

dependent (see Mechanical Specifications)

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)

Rated Full-Scale Current ➁ Min. 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

Overcurrent Rating ➁ 1.5 x rated full-scale current
Performance
Sampling Rate 2.5 samples per second
Accuracy ➁ ±0.15%FS ±6 counts
Measurement Type Sine wave input, full-wave

averaging, rms calibrated

Temperature Drift (0 to +60°C) — ±0.2 ±0.4 Counts/°C
Zero-Current Reading –001 000 001 Counts
Dielectric Withstanding Voltage 2000 — — Vdc
Power Supply Voltage ➄

ACA-20PC-X-AC1-XX 85 120 264 Vac@47-99Hz
ACA-20PC-X-AC2-XX 85 120 140 Vac@350-450Hz
ACA-20PC-X-AC3-XX 240 264 310 Vac@47-99Hz
ACA-20PC-X-DC1-XX +4.75 — +40 Vdc
ACA-20PC-X-DC2-XX +36 — +75 Vdc
ACA-20PC-X-DC3-XX +4.75 — +5.25 Vdc

Power Supply Current ➃

ACA-20PC-X-AC1,3-XX — 30 50 mA@47-99Hz
ACA-20PC-X-AC2-XX — 30 50 mA@350-450Hz
ACA-20PC-X-DC1,2-XX — +8 +12 mAdc
ACA-20PC-X-DC3-XX — +80 +120 mAdc

Power Supply Terminal Block
ACA-20PC-1-AC1-RL & ACA-20PC-2-AC1-RL

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

Wire Size & Type 12-20AWG (solid), 14-20AWG (stranded)
Insulation Strip Length 0.25 inches
Screw Tightening Torque 4.4 pound-inches (0.5Nm)
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/dc-powered models with 2-position terminal blocks):

Wire Size & Type 16-24AWG (solid or stranded)
Insulation Strip length 0.25 inches
Screw Tightening Torque 3.6 pound-inches (0.4Nm)
Maximum Rated Voltage 310Vac

Display
Display Type and Size 3½ digit LED, 0.37”/9.4mm digit height
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 %
Case Material Polycarbonate

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 Specified 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 specified 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, and –50Vdc on "DC2"

models. "DC3" models provide no reverse polarity protection.

Performance/Functional Specifications

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

IMPORTANT! To ensure safe and reliable operation, ACA­20PC ammeters must be installed and serviced by qualified
technical personnel. Contact DATEL if there is any doubt
regarding ammeter installation and/or operation.

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

rectified, average responding, rms-calibrated circuit to measure the
stepped-down output of their on-board, L1 current transformer (CT) .
Stated accuracy specifications are measured using a sine-wave
current at or close to the specified 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 qualified technical
personnel. Calibration is performed with potentially lethal voltages
applied to the ACA-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

Technical Notes

Ordering Information

ACA - 20PC - 1 - AC1 - RL

1 = 1.999A
2 = 19.99A
3 = 50.0A
4 = 100.0A

RL = Red Standard
RH = High-Intensity Red*
GS = Green Standard*

AC1 = 85-264Vac@50/60Hz
AC2 = 85-140Vac@400Hz
AC3 = 240-310Vac@50/60Hz
DC1 = +5-40Vdc
DC2 = +36-75Vdc
DC3 = +5Vdc

Accessories: DMS-20-CP Panel cutout punch

Input Range:

LED Color:

Power Supply:

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

*

Available on "DC3" +5V

powered models only

3

DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: [phone] Fax: [phone] • E–mail: [e-mail] • Internet: www.datel.com

3½ DIGIT, LED DISPLAY, AC AMMETERS

ACA-20PC Series

access the recessed calibration potentiometer located on the back of
the meter (see Mechanical Specifications). Contact DATEL if additional
information is required regarding calibration, setup, or any other
technical issue pertaining to the ACA-20PC.

3. Wire Gauges and Fusing: Wires specified in the Functional Specifica­tions 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 specific installation.

In particular, special attention must be paid to ACA-20PC-1-AC1-RL
and ACA-20PC-2-AC1-RL ac-powered models when their built-in
auxiliary terminal block connections (TB1) are used to supply current to
an external load. The supply wires connected to both the meter and the
load must be fused according to the current rating of the wire gauge
being used, in accordance with applicable regulatory codes. Also, wire
insulation should 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.

The ACA-20PC-3-ACX (0-50A range, ac-powered) and ACA-20PC-4-
ACX (0-100A, ac-powered) models’ TB1 is used only for powering the
meters' internal circuitry. It must not be used to supply current to
external loads. The supply wires feeding these meters must also be
fused according to the current rating of the wire gauge being used, in
accordance with applicable regulatory codes.

AC-powered models draw minimal steady-state supply currents (50mA
max.), and in most applications, they can be fused according to the
supply wire’s maximum amperage rating. However, these models can
draw significantly higher surge currents for brief periods when the ac
line voltage is initially applied.

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" 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 built­in 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 specifications of 4.4 pound-inches
(0.5Nm) for four-terminal ammeters (ACA-20PC-1-AC1-RL and ACA­20PC-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 Specifications for more information.

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

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 conductor
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, DATEL recommends using

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

Figure 2. Panel Installation

PANEL

1

PANEL

2

PANEL

4

3

PANEL

GASKET
(optional)

BEZEL

Panel Installation

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 Specifications 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 flange and
panel front surface (see Mechanical Specifications). Be sure to use and
securely tighten all four screws supplied with the bezel assembly.

First pass and carefully dress one external load wire through the on­board 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

Typical Wiring Diagrams

Panel Cutout and Bezel Installation

* Dimensions for ACA-20PC-4-XXX 100A model.

AC POWER

SUPPLY

TB1

A B

AC SUPPLY

TO

AC LOAD

ACA-20PC-X-ACX

L1

DC POWER

SUPPLY

TB1

A B

AC SUPPLY

TO

AC LOAD

ACA-20PC-X-DCX

L1

+

–

+

–

#2-56 INSERT

0.156 (3.96) DEEP

FRONT VIEW

1.280

(32.51)

0.187
(4.75)

DMS-BZL4 BEZEL

RECOMMENDED DRILL AND PANEL CUTOUT DIMENSIONS

1.826 (46.38)

0.838

(21.29)

1.350 (34.29)

*

1.626 (41.30)

1.07

(27.18)

INTERNAL CORNER RADII:

0.032 (0.81) MAX.

0.138 (3.51)

*

0.093 (2.362) DIAMETER (4 REQUIRED)
ONLY WHEN USING OPTIONAL BEZEL ASSEMBLY

0.116 (2.95)

BEZEL INSTALLATION

BEZEL

PANEL

GASKET
(optional)

®®

1.336 (33.93)

0.145 (3.68)

FUSED

85-264Vac

POWER

TB1

A B

L1

85-264Vac TO LOAD

TB1

A B

L1

TO LOAD

FUSED

85-264Vac

POWER

ACA-20PC-1-AC1-RL

ACA-20PC-2-AC1-RL

4

DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: [phone] Fax: [phone] • E–mail: [e-mail] • Internet: www.datel.com

ACA-20PC Series

3½ DIGIT, LED DISPLAY, AC AMMETERS

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

ACA-20PC-3 Series

Mechanical Specifications

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

ACA-20PC-4 Series

0.80

(20.3)

0.040
(1.02)

1.30

(33.0)

1.38

(35.1)

0.88

(22.4)

1.00

(25.4)

1.54

(39.1)

0.040
(1.02)

0.040
(1.02)

2.12

(53.8)

TB1

A B

CAL.

®®

Hole Diameter:

0.35 (8.9) min.

FRONT VIEW BACK VIEW

0.80

(20.3)

0.040
(1.02)

1.30

(33.0)

1.38

(35.1)

0.88

(22.4)

1.00

(25.4)

1.32

(33.5)

0.040

(1.02)

0.040
(1.02)

2.01

(51.1)

TB1

A B

CAL.

®®

FRONT VIEW BACK VIEW

Hole Diameter:

0.27 (6.9) min.

0.80

(20.3)

0.040
(1.02)

1.30

(33.0)

1.38

(35.1)

0.88

(22.4)

1.00

(25.4)

1.32

(33.5)

0.040

(1.02)

0.040
(1.02)

2.01

(51.1)

TB1

A B

CAL.

®®

FRONT VIEW BACK VIEW

Hole Diameter:

0.27 (6.9) min.

0.80

(20.3)

0.040

(1.02)

1.30

(33.0)

1.38

(35.1)

0.88

(22.4)

1.00

(25.4)

1.32

(33.5)

0.040

(1.02)

0.040

(1.02)

2.53

(64.3)

TB1

A B

CAL.

®®

1.33

(33.8)

*

*

THIS MODEL REQUIRES A PANEL

CUTOUT WIDTH OF 1.350" (34.3MM)

Hole Diameter:

0.55 (14.0) min.

FRONT VIEW BACK VIEW

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

ACA-20PC-1 & 2

2A and 20A, all other models

50A models 100A models

DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: [phone] [phone] Fax: [phone]
Internet: www.datel.com Email: [e-mail]

DATEL (UK) LTD. Tadley, England Tel: [phone]
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: [phone]
DATEL GmbH München, Germany Tel: [phone]
DATEL KK Tokyo, Japan Tel: [phone], Osaka Tel: [phone]

DATEL 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. The DATEL logo is a registered DATEL, Inc. trademark.

DS-0447B 11/2000

® ®

ISO 9001

REGISTERED

3½ DIGIT, LED DISPLAY, AC AMMETERS

ACA-20PC Series