ACA-20PC Series
Digital, LED-Display AC Ammeters with
Built-in Current Transformers
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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
DATEL's new ACA-20PC Series are the first 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 resolution). 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-film resistors for
unsurpassed accuracy (±0.15%FS) and stability.
■
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; UL/CSA recognized
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.
SIMPLIFIED SCHEMATIC DIAGRAM
CAL.
+
3½ DIGIT
A/D CONVERTER
–
+V
–V
LED DISPLAY
RMS-to-DC
CONVERTER
(L1)
BUILT-IN
CURRENT
TRANSFORMER
POWER
CONVERTER
A
B
Figure 1. ACA-20PC Series simplified schematic
TB1
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MEASURED AC
LOAD CURRENT
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AC INPUT POWER
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MPM_ACA_20PC.B05 Page 1 of 6
ACA-20PC Series
Digital, LED-Display AC Ammeters with
Built-in Current Transformers
Performance/Functional Specifications
Typical at TA = +25°C, unless otherwise noted. ➀
Min.
Typ.
Max.
Units
Physical/Environmental
ACA-20PC-1-XXX-XX
–
–
1.999
Amps
Case Material
ACA-20PC-2-XXX-XX ➂
–
–
19.99
Amps
Dimensions
ACA-20PC-3-XXX-XX
–
–
50.0
Amps
ACA-20PC-4-XXX-XX
–
–
100.0
Amps
DMS-30798-C
–
–
30.0
Amps
Full-Scale Current (45-450Hz) ➁
1.5 x rated full-scale current
Overcurrent Rating ➁
Performance
Sampling Rate
2.5 reading per second
Accuracy ➁
±0.15%FS ±6 Counts
Measurement Type
Temperature Drift (0 = +60°C)
Zero Reading (Vin = 0 Volts)
Dielectric Withstanding Voltage
Sine wave input, full-wave averaging, rms
calibrated
–
±0.2
±0.4
Cnts/°C
“–001”
“000”
“001”
Counts
–
±0.4
±1
Vdc
Power Supply Voltage ➄
ACA-20PC-X-AC1-RL (47-99Hz)
85
120
264
+4.75
–
+40
ACA-20PC-X-AC1-RL (47-99Hz)
–
30
50
mA
ACA-20PC-X-DC1-RL
–
+8
+12
mAdc
ACA-20PC-X-DC1-RL
Vac
Vdc
Power Supply Current ➃
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
0.25 inches
Screw Tightening Torque
4.4 pounds/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 or dc-powered models with 2-position terminal blocks):
Wire Size and Type
16-24AWG (solid or stranded)
Insulation Strip Length
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)
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.
ACA - 20PC - 1 - AC1 - RL - L - C
(45-450Hz)
Input Range:
1 = 1.999A
2 = 19.99A
3 = 50.0A
4 = 100.0A
RoHS
Leaded CT (100A model)
LED Color:
RL = Red Standard
BL = Blue Standard
PGL = Green Standard
Power Supply:
AC1 = 85-264Vac@50/60Hz
DC1 = +5-40Vdc
DMS-30798-C: 30Amp model with a wire lead CT and “-AC1”
power supply specifications. See Mechanical section for dimensions.
0.25 inches
Screw Tightening Torque
1.38”W x 0.88”H. Depth is model dependent
(see mechanical specification)
Ordering Information
12-20AWG (solid), 14-20AWG (stranded)
Insulation Strip Length
Polycarbonate
3.6 pounds/inches (0.5Nm)
Accessories: DMS-20-CP Panel cutout punch
Display
Display Type and Size
3½ digit, 0.37"/9.4mm high LED
Overrange Indication
“1_ _ _“
Decimal Point
A DMS-BZL4-C bezel assembly with sealing gasket is supplied with each ammeter.
Fixed, model dependent
Physical/Environmental
Operating Temperature
Storage Temperature
Humidity (non-condensing)
0
–
+60
°C
–40
–
+75
°C
0
–
95
%
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Technical enquiries email: [email protected], tel: +1 508 339 3000
MPM_ACA_20PC.B05 Page 2 of 6
For full de
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ACA-20PC Series
Digital, LED-Display AC Ammeters with
Built-in Current Transformers
TECHNICAL NOTES
IMPORTANT! To ensure safe and reliable operation, ACA-20PC
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-waverectified, 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 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.
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 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 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 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.
PANEL 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.
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).
The ACA-20PC-3-ACX (0-50A range, ac-powered) and ACA-20PC4-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.
To ensure a secure panel-mount installation, DATEL 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 Specifications for detailed cutout and
ammeter dimensions.
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.
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.
4. AC Supply Polarity and Grounding: The two ac supply inputs,
TB1-A and TB1-B, on ac-powered ammeters are not in themselves
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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.
Technical enquiries email: [email protected], tel: +1 508 339 3000
MPM_ACA_20PC.B05 Page 3 of 6
ACA-20PC Series
Digital, LED-Display AC Ammeters with
Built-in Current Transformers
Step 1.
Step 2.
Step 3.
Step 4.
Panel
Figure 2. Panel Installation
TYPICAL WIRING DIAGRAM
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.
&53%$
6AC
0/7%2
&53%$
6AC
0/7%2
!#0/7%2
3500,9
ACA-20PC-X-ACX
4/!#,/!$
ACA-20PC-1-AC1-RL
!#3500,9
Figure 4. All Other AC-Powered Models
ACA-20PC-2-AC1-RL
$#0/7%2
3500,9
n
6AC4/,/!$
4/,/!$
ACA-20PC-X-DCX
Figure 3. 2A and 20A, 85-264V AC-Powered Models
With Auxilliary Load Connections
n
4/!#,/!$
!#3500,9
Figure 5. All DC-Powered Models
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Technical enquiries email: [email protected], tel: +1 508 339 3000
MPM_ACA_20PC.B05 Page 4 of 6
ACA-20PC Series
Digital, LED-Display AC Ammeters with
Built-in Current Transformers
MECHANICAL SPECIFICATIONS
ACA-20PC-1 & 2-AC1-RL
ACA-20PC-1 & 2
2A and 20A, 85-264V ac-powered models
2A and 20A, all other models
Hole Diameter:
0.27 (6.9) min.
Hole Diameter:
0.27 (6.9) min.
2.01
(51.1)
1.00
(25.4)
0.040
(1.02)
®
®
®
0.040
(1.02)
1.30
(33.0)
1.38
(35.1)
0.040
(1.02)
0.80
(20.3)
0.88
(22.4)
1.00
(25.4)
®
0.040
(1.02)
2.01
(51.1)
0.040
(1.02)
1.30
(33.0)
1.38
(35.1)
0.040
(1.02)
1.32
(33.5)
FRONT VIEW
0.80
(20.3)
0.88
(22.4)
1.32
(33.5)
BACK VIEW
FRONT VIEW
BACK VIEW
CAL.
CAL.
ACA-20PC-3 Series
ACA-20PC-4 Series
50A models
100A models
1.33
(33.8)
Hole Diameter:
0.35 (8.9) min.
MODEL REQUIRES A PANEL
* THIS
CUTOUT WIDTH OF 1.350" (34.3MM)
*
Hole Diameter:
0.55 (14.0) min.
2.53
(64.3)
2.12
(53.8)
0.040
(1.02)
®
®
1.30
(33.0)
1.38
(35.1)
®
0.040
(1.02)
1.00
(25.4)
0.040
(1.02)
0.80
(20.3)
0.88
(22.4)
0.040
(1.02)
1.54
(39.1)
FRONT VIEW
BACK VIEW
CAL.
1.00
(25.4)
®
0.040
(1.02)
1.30
(33.0)
1.38
(35.1)
0.040
(1.02)
0.80
(20.3)
0.88
(22.4)
1.32
(33.5)
FRONT VIEW
BACK VIEW
CAL.
Mechanical Dimensions: Inches (mm) Tolerances: 2 PL DEC ±0.02 (±0.51), 3 PL DEC ±0.010 (±0.254)
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MPM_ACA_20PC.B05 Page 5 of 6
ACA-20PC Series
Digital, LED-Display AC Ammeters with
Built-in Current Transformers
BEZEL INSTALLATION AND RECOMMENDED DRILL AND
PANEL CUTOUT
MECHANICAL SPECIFICATIONS, CONTINUED
0.187
(4.75)
#2-56 INSERT
0.156 (3.96) DEEP
ACA-20PC-4-XXX-L (100A model)
DMS-30798-C (30A model)
OD: 100A Model: 1.18 (30.0)
DMS-30798-C (30A): 0.87 (22.0)
1.280
(32.51)
FRONT VIEW
ID: 100A Model: 0.58 (14.7)
DMS-30798-C (30A): 0.35 (8.9)
1.826 (46.38)
1.07
(27.18)
0.040
(1.02)
®
1.30
(33.0)
1.38
(35.1)
0.838
(21.29)
PANEL CUTOUT
1.00
(25.4)
0.093 (2.362) DIA
(4 REQUIRED)
®
0.040
(1.02)
0.116 (2.95)
INTERNAL CORNER RADII:
0.032 (0.81) MAX.
Lead Length:
2.0 (50.5) min.
0.040
(1.02)
0.80
(20.3)
0.88
(22.4)
1.626 (41.30)
* 1.350 (34.3) for ACA-20PC-4-XXX 100A model.
Gasket
1.14
(29.0)
FRONT VIEW
0.145 (3.68)
1.336 (33.93)*
BACK VIEW
CAL.
"%:%,
®
®
USA:
Mansfield (MA), Tel: (508) 339-3000, email: [email protected]
Canada: Toronto, Tel: (866) 740-1232, email: [email protected]
Murata Power Solutions, Inc.
11 Cabot Boulevard, Mansfield, MA 02048-1151 U.S.A.
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
UK:
Milton Keynes, Tel: +44 (0)1908 615232, email: [email protected]
France:
Montigny Le Bretonneux, Tel: +33 (0)1 34 60 01 01, email: [email protected]
Germany: München, Tel: +49 (0)89-544334-0, email: [email protected]
www.murata-ps.com email: [email protected] ISO 9001 REGISTERED
Japan:
Tokyo, Tel: 3-3779-1031, email: [email protected]
Osaka, Tel: 6-6354-2025, email: [email protected]
Website: www.murata-ps.jp
China:
Shanghai, Tel: +86 215 027 3678, email: [email protected]
Guangzhou, Tel: +86 208 221 8066, email: [email protected]
06/25/08
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. © 2008 Murata Power Solutions, Inc.
www.murata-ps.com
Technical enquiries email: [email protected], tel: +1 508 339 3000
MPM_ACA_20PC.B05 Page 6 of 6