ACA-20RM Series
True-RMS-AC Ammeters with Built-in CT
FEATURES
Built-in CTs provide true-rms values of complex
waveforms
Perfect for measuring AC current in IT applications
Five ranges measure: 0-0.2A, 0-2A, 0-20A, 0-30A
and 0-50A
50A models features a split-core CT for easy installation
Self-powered from 85-140Vac or 170-264Vac
Large, easy-to-read, red LED display with 0.37” digits
Reliable single-board construction
Digital replacement for analog meters
UL and CSA recognized components
Murata Power Solution’s new ACA-20RM Series are the world’s first digital ac-ammeters
to incorporate a built-in current transformer (CT) to directly measure the true-rms value of
complex, non-sinusoidal ac currents from 2 to 50A – no bulky and expensive 5A “donut”
CTs are required! Operation and setup is straightforward: simply pass the load-carrying
wire through the on-board CT, apply power, and the ammeter is fully operational.
Five input ranges measure 0-0.2 amps (0.1mA resolution), 0-2 amps (0.001A resolution),
0-20 amps (0.01A resolution), 0-30 amps (0.1A resolution) or 0-50 amps (0.1A resolution).
The 50A model features an oversized split-core current transformer that easily accommo-
dates wires sizes up to 4 AWG (21.2mm
2
). Two power supply options are available: 85-140V
(47-63Hz), and 170-264V (47-63Hz).
All models are totally self-contained; no external components are required. Power con-
sumption from a nominal 120V or 220V ac supply is less than 50mA. And, precision auto-
zeroing circuitry, super-stable components, and an rms-to-dc converter circuit combine to
achieve excellent performance when measuring the complex, non-sinusoidal, ac currents
found in today’s computer/telecom equipment.
ACA-20RM Series ammeters feature full-size, 0.37” (9.4mm) high, 3�½ digit, bright red
LED-displays and a built-in bezel/filter assembly that features metal fasteners. They are
panel-cutout compatible with MPS’s DMS-20 Series of ac voltage and frequency monitors,
making ACA-20RM ammeters perfect replacements for older, less reliable, analog panel
meters in today’s sophisticated IT instrumentation.
CAL.
+
3�½ DIGIT
A/D CONVERTER
–
+V
RMS-to-DC
CONVERTER
–V
LED DISPLAY
(L1)
POWER
CONVERTER
BUILT-IN
CURRENT
TRANSFORMER
A
B
TB1
For full details go to
www.murata-ps.com/rohs
MEASURED AC
LOAD CURRENT
AC INPUT POWER
www.murata-ps.com
Technical enquiries
email: sales@murata-ps.com, tel:
+1 508 339 3000
MPM_ACA-20RM_B02
Page 1 of 5
MURATA-PS [ MURATA POWER SOLUTIONS INC. ]
