Specifications

Performance/Functional Specifi cations
Typical at TA = +25°C, unless otherwise noted.
Input Range:
Full-scale load current
1 = 199.9μA
2 = 1.999mA
3 = 19.99mA
4 = 199.9mA
5 = 1.999A
6 = 19.99A
DCA-20PC - 1 - DC1 - R L - C
Accessories:
DMS-20-CP Panel Cutout Punch
➀ The noted full-scale values are the external load currents that the ammeter is
designed to measure. This current enters TB-1 (-SHUNT), passes through the am-
meter’s built-in shunt and exits via TB1-2 (+SHUNT). For all models, this same full-
scale load current can also be routed, if the user so chooses, through TB2-1 and
TB2-2 (connection to positive rail of power supply). See detailed wiring diagrams.
Measuring positive and negative currents (bipolar operation): In applications
where both positive and negative currents must be measured, Murata Power Solu-
tions recommends using ‘-DC4’ 8-36V isolated supply models. Negative current
fl ow is denoted by the illumination of the display’s negative (-) sign; the absence
of a negative sign implies positive current fl ow. Contact MPS if you have any ques-
tions regarding bipolar operation of DCA-20PC ammeters.
➁ For all models, the application of 1.5 times the rated full-scale load current is
permissible as long as this overcurrent condition does not exceed 6 seconds and
occurs no more than once in a 60 second interval (10% duty cycle).
➂ Breakdown (isolation) voltage applies only to ‘-DC4’ isolated-power models. Break-
down voltage is tested with TB1-1 tied to TB1-2 (-SHUNT shorted to +SHUNT),
and TB2-1, TB2-2, and TB2-3 all tied together (+V shorted to -V). 500Vdc is then
applied between the two shorted terminal-block pairs; the maximum permissible
leakage current is 5uA.
➃ Zero reading is measured with TB1-1 (-SHUNT) shorted to TB1-2 (+SHUNT).
➄ The Operating power supply voltage is applied to TB2-1-2 (+V) and TB2-3 (-V)
on ‘-DC4’ models, and to TB1-1 (-SHUNT) and TB2-2 (+V) on ‘-DC1’ models. On
all models, TB2-1 and TB2-2 are internally tied together (+V). Operating supply
current is the current which powers the meter’s analog and digital circuits; it is
measured with zero load-current passing through the ammeter’s built-in shunt
(i.e., with the display reading “000” and one decimal point enabled).
On 5-40Vdc powered (‘-DC1’), grounded-shunt models, the ammeter’s operating
supply current enters TB1-1 (-Shunt) but is not included in the displayed reading
(i.e., it does not pass through the built-in shunt).
A DMS-BZL4-C bezel assembly with sealing gasket is
supplied with each ammeter.
Full Scale Load Current ➀
Min. Typ. Max. Units
DCA-20PC-1
– – 199.9 μAdc
DCA-20PC-2
– – 1.999 mAdc
DCA-20PC-3
– – 19.99 mAdc
DCA-20PC-4
– – 199.9 mAdc
DCA-20PC-5
– – 1.999 Adc
DCA-20PC-6
– – 19.99
Adc
Overcurrent Rating (<6 sec.) ➁
1.5x rated full-scale load current
Internal Shunt Resistance
DCA-20PC-1
– – 100 Ohms
DCA-20PC-2
––10Ohms
DCA-20PC-3
– – 1.0 Ohm
DCA-20PC-4
– – 0.1 Ohm
DCA-20PC-5
– – 0.01 Ohm
DCA-20PC-6
– – 0.001 Ohm
Shunt Input to Power Supply Isolation ➂
DCA-20PC-X-DC4 models only 500 – – Volts
Performance
Sampling Rate
2.5 reading per second
Accuracy
±0.15%FS
Zero-Current Reading ➃
“–001” “000” “001” Counts
Temperature Drift (0 = +60°C) – ±0.2 ±0.4 Cnts/°C
Operating Supply Voltage (TB2 Terminals 1, 2 and 3) ➄
DCA-20PC-X-DC1-XX +5.0 – +40 Vdc
DCA-20PC-X-DC4-XX +8 – +36 Vdc
Operating Supply Current (TB2 Terminals 1, 2 and 3) ➄
DCA-20PC-X-DC1-XX (@ 5-40V) – 10 15 mAdc
DCA-20PC-X-DC4-XX (@ 8V) – 100 150 mAdc
DCA-20PC-X-DC4-XX (@ 36V) – 25 40 mAdc
TB1 and TB2 Terminal Blocks
Wire Size
12-20AWG, (solid)
14-20AWG, (stranded) copper wire
Insulation Strip Length
0.250 inches
Screw Tightening Torque
4.4 pound/inches (0.5Nm)
Rated Current
20A with 12AWG solid copper wire;
15A with 14AWG solid or stranded
copper wire
Display
Display Type and Size
3½ digit, 0.37"/9.4mm high red, blue or
green LED
Overrange Indication
"–1_ _ _" for negative Vin
"1_ _ _" for positive Vin
Display Reading/Decimal Point
Model dependent
Physical/Environmental
Operating Temperature
0 – +60 °C
Storage Temperature
–20 – +75 °C
Add -C for RoHS
Ordering Information
Physical/Environmental (continued)
Humidity (non-condensing)
0–85%
Case Material
Polycarbonate
Dimensions
1.38"W x 0.88" x 1.0" nominal
Weight
0.6 ounces (17 grams)
Power Supply:
DC1 = +5-40Vdc, non-isolated power
(available with -RL, -BL, or -PGL LEDs)
DC4 = +8-36Vdc, isolated power
(available with -RL, -BS, or -GS LEDs)
LED Color:
BL = Low-Power Blue
BS = Super Blue
GS = Standard Green
PGL = Low-Power Green
RL = Low-Power Red
www.murata-ps.com/support
DCA-20PC Series
LED Display, Subminiature DC Ammeters
with Built-In Shunts
MPM_DCA-20PC.B07 Page 2 of 6