www.murata-ps.com
DMU-30DCV Series
Ruggedized DC Voltmeters with Daylight Readable
Auto-Dimming LED Displays
FEATURES
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Measure and accurately display dc voltages in harsh
environments
Four input ranges: ±200mVdc, ±2Vdc, ±20Vdc, and
±200Vdc
Daylight-readable LED display with automatic
brightness adjustment
Moisture & impact resistant package offers
NEMA-4/IP65 protection
Operates from universal 85-264Vac mains, or
110-300Vdc supplies
Input circuit fully isolated from ac power supply
UL certification pending
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Murata Power Solutions’ DATEL branded DMU-30DCV series of daylight-readable dc
voltmeters measure and display dc signals as low as ±200mV and as high as ±200V. Their
large 0.56” (14.2mm) high super-bright red LED-display is readable in full sunlight. An
auto-dimming circuit automatically adjusts the display brightness for all viewing conditions.
DMU-30DCV series dc voltmeters are packaged in a rugged, one-piece polycarbonate
plastic housing that features an integrated bezel and gasket assembly. In a typical instal-
lation, the housing is secured to a panel with six metallic threaded inserts, allowing the
unit to meet NEMA-4 / IP65 requirements for moisture and impact resistance in outdoor
applications.
DMU-30DCV series dc voltmeters are available in a choice of four input ranges:
±200mVdc (with 0.1mV resolution); ±2Vdc (0.001V resolution); ±20Vdc (0.01V resolution);
and ±200Vdc (0.1V resolution). The dc signal under measurement is electrically isolated
from the unit’s operating power source.
DMU-30DCV series’ miniature size and rugged package are perfect for industrial and
high-reliability instrumentation, alternative power generators, and any other application
which requires daylight readability and precise monitoring of dc voltages in harsh indoor /
outdoor environments. Simply connect the input signal and an 85-264Vac source of operat-
ing power to the two rear-mounted terminal blocks and the unit is fully operational.
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TECHNICAL NOTES
IMPORTANT! To ensure safe and reliable operation, DMU-30DCV dc voltmeters must
be installed and serviced by qualified technical personnel. Contact Murata / DATEL if
there is any doubt regarding installation and/or operation.
1. Measurement Type:
All DMU-30DCV series dc voltmeters achieve their excellent
performance by employing a precision integrating analog-to-digital converter, metal film
resistor dividers, and a high-stability voltage reference IC. The LED display is updated
approximately 2.5 to 3 times per second. However, while some input filtering is provided,
noisy signals may cause the displayed reading to vary by a few counts.
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CAL
BRIGHTNESS
ADJUST
2. Wiring:
All ac supply (TB1) and input signal (TB2) wiring must be adequately rated for
the voltages and currents they will carry, and must comply with any code or application-
mandated requirements pertaining to the user’s specific installation.
3. Power Supply Polarity, Fusing, and Grounding:
The operating-supply terminals (TB1-1
and TB1-2) on DMU-30DCV voltmeters are not polarity sensitive, that is, they have no “AC
LO” or “AC HI” designations. These units do not include or require a connection to earth/
chassis ground. Refer to Figure 1 for a typical wiring diagram.
DMU-30DCV dc voltmeters are not internally fused. If fusing is required, it must be exter-
nally user-provided according to the supply wire’s maximum amperage rating.
1
TB1
2
1
2
TB2
REAR VIEW
85-264Vac
Power Source
Input Signal
Figure 1. DMU-30DCV wiring diagram
For full details go to
www.murata-ps.com/rohs
4. Calibration:
Periodic recalibration of DMU-30DCV voltmeters is not required under
normal indoor operating environments. However, operation in environments subject to
vibration and/or extreme temperature variations should have their accuracy verified
on a yearly basis. If recalibration is necessary, it should only be performed by qualified
technical personnel. Calibration is performed with potentially lethal voltages applied to
the DMU-30DCV and its associated wiring. A plastic, fully-insulated adjusting tool must be
used to access the recessed calibration potentiometer located on the back of the unit (see
Mechanical Specifications). Contact Murata / DATEL if additional information is required
regarding calibration, setup, or any other technical issue pertaining to DMU-30DCV dc
voltmeters.
Technical enquiries
email: sales@murata-ps.com, tel:
+1 508 339 3000
MPM_DMU_30DCV.A05
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