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DMS-20ACV Series

480V, Self-Powered, AC Line Monitor

MPM_DMS-20ACV.B02 Page 2 of 4

TECHNICAL NOTES

IMPORTANT! To ensure safe and reliable operation, DMS-20ACV ac

voltmeters must be installed and serviced by qualified technical

personnel. Contact Murata Power Solutions if there is any doubt

regarding installation and/or operation.

1. Measurement Type: DMS-20ACV series AC voltmeters employ a

precision analog-to-digital converter and a stable voltage reference to

measure and display the average value of sinusoidal AC mains voltages.

Input voltages of 601V and above will cause the display to flash on and

off.

2. Calibration: DMS-20ACV voltmeters are digitally calibrated at the fac-

tory; there is no provision for calibrating units in the field.

3. Power Supply Polarity, Fusing, Wiring, and Grounding: DMS-20ACV-3’s

TB1 ac-supply terminals are not polarity sensitive, that is, they have

no “AC LO” or “AC HI” designations. These meters do not include nor

require a connection to earth/chassis ground.

DMS-20ACV-3 AC voltmeters are not internally fused. Terminal block

TB1 is to be used only for powering the voltmeter’s internal circuitry; it

must not be used to supply power to external loads or auxiliary devices.

The supply wires connected to TB1 must be fused with a 0.25A/600V

time delay/time lag fuse, in accordance with applicable regulatory

codes.

All AC-supply wiring must be rated for the voltages and currents they

will conduct and comply with any code or application-mandated

requirements pertaining to the user’s specific installation. 600V, UL-

rated wire suitable for the intended application is required.

The recommended AC supply wire size is 16AWG to 22AWG (1.31mm2

to 0.325mm2) stranded copper wire. The supply wires must be properly

stripped and attached to TB1 such that their insulation is not pinched

by the screw terminal. Recommended insulation strip length is 0.25"

(6.4mm). Rated tightening torque for the TB1’s screws is 7 pound-

inches (0.8 N-m).

Performance/Functional Specifications

Typical at Ta=+ 25°C, 480Vac @ 60Hz, unless otherwise noted

Input Supply Voltage (Vin @ TB1)

Min.

Typ.

Max.

Units

AC (rms) Voltage @ 47-63Hz

350

480

600

Volts AC

Performance

Sampling Rate

2

samples/sec

Voltage Accuracy @ 25° C

±2

±4

Volts

Temperature Drift (0 to 60ºC)

0.05

Volts/°C

Measurement Type

Half-wave averaging, rms calibrated for

sinusoidal inputs

Supply Current

@ 50Hz

8

11

mA

@ 60Hz

9

13

mA

Display

Display Type

3 Digit LED

Display Size

0.40 inches (10.16mm) high

Overrange Indication

Flashing display for Vin > 600 Volts

Physical/Environmental

Weight

1.0 ounces (28 grams)

Operating Temperature

-25

60

°C

Storage Temperature

-40

75

°C

Relative Humidity (Non Condensing)

0

85

%

Ordering Information*

DMS-20ACV-3-R-C

350 to 600Vac (50/60Hz) Red LED Display

DMS-20ACV-3-G-C

350 to 600Vac (50/60Hz) Green LED Display

*See technical note 3.

Figure 1. Wiring Diagram

*See www.murata.com/product/power for model-specific availability.