NANO
DMR20-10-DCM
www.murata-ps.com
2-Wire, Self-Powered,
Auto-Ranging DC Voltage Monitor
FEATURES
Self-powered, requires only two connections
Auto-ranging 6 to 75Vdc input range
Installs in round “oiltight” 1.20 inch (30.5mm) cutouts
Reverse polarity protected to –100Vdc
Four-digit LED display with overvoltage indication
Digital replacement for analog panel meters
Screw-style terminal block simplifies installation
Self-resetting internal fuse for long-term reliability
Provides moisture resistance to IP67/NEMA 6
Supplied with EPDM rubber gasket and plastic hex nut
Panel knockout punches and tooling available
Murata Power Solutions’ new DMR20-10-DCM self-powered, auto-ranging DC voltage
monitors are designed to measure and display the outputs the most popular DC power
systems. Simply connect any 6 to 75V DC power source and these meters are fully opera-
tional—no additional components or power sources are required.
Performance/Functional Specifications
Their large, 0.30"/7.6mm, bright LED displays can be easily read from 10 feet away (3
meters). These auto-ranging meters accurately display DC voltages with 0.01V in the LO
Range (below 51V), or 0.1V resolution in the HI Range (above 51 V). A built-in resettable
fuse assures long term reliability. All DMR20-10-DCM’s employ a 13-bit A/D converter
and precision metal-film resistors to achieve outstanding performance over an operating
temperature range of –25 to +60°C.
Typical at Ta = +25°C, unless otherwise noted
DC Input (TB1)
Input voltage range ➀
Current Consumption
Reverse Polarity Protection
+6 to +75Vdc
@Vin = 75.0Vdc: 7mA (max.)
-100Vdc (min.)
Performance
The DMR20-10-DCM is housed in a rugged, round polycarbonate case that provides excel-
lent protection against moisture, dust, shock and vibration. Panel installation is straightfor-
ward: using readily available tooling, simply drill and punch a 1.2 inch (30.5mm) diameter
hole and anti-rotation notch, insert the meter and gasket into the panel, and securely fasten
the meter using the supplied hex nut. The supplied hardware is designed to provide protec-
tion to IP67/NEMA 6.
Sampling Rate
Resolution
2.5 readings/second
0.01Vdc in LO Range;
0.1Vdc in HI Range
Accuracy @ +25°C
0.2V (typ.), 0.4V (max.)
0.03V (typ.), 0.06V (max.)
See note 3
HI Range ➁
LO Range ➁
Overrange Indication ➂
Temperature Drift
0.003V/°C (typ.)
Mechanical
Dimensions
1.50"diameter x 1.08 depth"
(38.1 x 27.4mm)
Ordering Information
DMR20-10-DCM-R-C 6 to 75Vdc voltage monitor (Red LED)
Display Type
Weight
Four digit, LED, 0.30" high (7.6mm)
0.6 ounces (18 grams)
with nut and gasket
Tooling
DMR20-1-KP
DMR20-2-KP
DMR20-3-KP
1.2" (30.5mm) Round knockout punch
(no keying notch)
1.2" (30.5mm) Round knockout punch
(with four keying notches)
1/8" and 3/16" (3.2 and 4.7mm)
key-notch nibbler tool
Case Material
Terminal Block Torque
Wire Size And Type
Polycarbonate
3.6 in-lbs (0.4 N-m)
18-22AWG (0.83-0.33mm2) copper,
solid or stranded
Wire Insulation Strip Length
0.25" (6.4mm)
Environmental
Operating Temperature
Storage Temperature
Humidity (non-condensing)
Note: An M30 x 1.5 nylon hex nut and EPDM sealing gasket are supplied with each meter.
The “-C” suffix denotes RoHS compliance.
–25 to +60°C
–40 to +75°C
0 to 85%
➀ Operation and accuracy at inputs above or below these ranges are not specified.
➁ When auto-range operation is enabled via jumper JP1 and Vin is between 6V to 51V, the
displayed resolution is 0.01V (i.e., the unit is in LO Range). When Vin is 51V and above, display
resolution is 0.1V (i.e., the unit is in HI Range). When the unit is in the HI range and Vin drops
below 49V, it will auto-range back to the LO Range.
➂ When Vin is between 75V and 80V, the display will alternate from dim to normal intensity at
approximately one second intervals. When Vin exceeds 80V, display will flash on and completely
off at approximately one second intervals. Continuous operation above 80V will permanently
damage the meter and void its warranty.
For full details go to
www.murata-ps.com/rohs
www.murata-ps.com/support
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