DMU-30DCV Series

Ruggedized DC Voltmeters with Daylight Readable

Auto-Dimming LED Displays

MPM_DMU_30DCV.A05 Page 1 of 3

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TB1

TB2

CAL

BRIGHTNESS

ADJUST

REAR VIEW

85-264Vac

Power Source

Input Signal

1

2

1

2

Figure 1. DMU-30DCV wiring diagram

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.

FEATURES

environments

±200Vdc

brightness adjustment

NEMA-4/IP65 protection

110-300Vdc supplies

TECHNICAL NOTES

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.

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.

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.

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.