DMR20-1-KP - MURATA MANUFACTURING

Murata Power Solutions’ new DMR20-1-ACV self-powered, AC line-voltage monitors are

designed to measure and display the true-rms voltage of AC power systems. Simply con-

nect any 85 to 264Vac 50/60Hz power source and these meters are fully operational—no

additional components or power sources are required. The unit can also measure distorted

AC power sources including triangle, square, and the quasi-sine output of many DC to AC

power inverters.

The DMR20-1-ACV is housed in a rugged, round polycarbonate case that provides excellent

protection against moisture, dust, shock and vibration. Panel installation is straightforward:

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, and securely fasten the meter using the sup-

plied hex nut. The supplied hardware is designed to provide protection to IP67/NEMA 6.

Their large, 0.30"/7.6mm, bright LED displays can be easily read from 10 feet away (3

meters). These meters accurately display ac voltages with 0.1V resolution. A built-in reset-

table fuse assures long term reliability. All DMR20-1-ACVs employ a 13-bit A/D converter

and precision metal-ﬁ lm resistors to achieve outstanding performance over an operating

temperature range of –25 to +60°C.

➀ Operation and accuracy at inputs above or below these ranges are not speciﬁ ed.

Performance/Functional Speciﬁ cations

Typical at Ta = +25°C, Vin = 250Vac / 60Hz sine wave, unless

otherwise noted

AC Input (TB1)

Voltage Range ➀85 to 264Vac (47-63 Hz)

Current Consumption @Vin = 250Vac: 30mA (max.)

@Vin = 120Vac: 15mA (max.)

UL/IEC61010-1 Measurement Category II

Performance

Sampling Rate 2.5 readings/second

Resolution 0.1Vac

Accuracy @ +25°C ±0.5Vac (typ.), ±0.9Vac (max.)

Temperature Drift (–25 to +60°C) ±0.05V/°C (max.)

Mechanical

Dimensions 1.50"diameter x 1.15 depth"

(38.1 x 29.2mm)

Display Type Four digit, LED, 0.30" high (7.6mm)

Weight 0.8 ounce (23 grams)

Case Material Polycarbonate

Terminal Block Torque 2.2 lb·in (0.25 N·m) ±20%

Wire Size And Type 18-22AWG (0.83-0.33mm2) copper,

solid or stranded

Wire Insulation Strip Length 0.25" (6.4mm)

Environmental

Operating Temperature –25 to +60°C

Storage Temperature –40 to +75°C

Humidity (non-condensing) 0 to 85%

Ordering Information

DMR20-1-ACV-R-C 85 to 264Vac voltage monitor (Red LED)

Knockout Punches

DMR20-1-KP 1.2" (30.5mm) Round knockout punch

(no keying notch)

DMR20-2-KP 1.2" (30.5mm) Round knockout punch

(with four keying notches)

DMR20-3-KP 1/8" and 3/16" (3.2 and 4.7mm)

key-notch nibbler tool

Note: An M30 x 1.5 nylon hex nut and EPDM sealing gasket are supplied with each

meter. The “-C” sufﬁ x denotes RoHS compliance.

E156931

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For full details go to

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DMR20-1-ACV

Self-Powered,

85 to 264Vac, LED Display Line Monitor

MPM_DMR20-1-ACV.B01 Page 1 of 4

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FEATURES

 Universal 85 to 264Vac measurement range

 Self-powered directly from the AC supply

 Installs in “oiltight”1.20 inch (30.5mm) round cutouts

 Four-digit LED display with overvoltage indication

 Reads true-rms value to 0.1V resolution

 Knockout punches and tooling available

 Digital replacement for analog panel meters

 Screw-style terminal block simpliﬁ es 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

 Approvals to UL/cUL/IEC/ 61010-1

TECHNICAL NOTES

IMPORTANT! To ensure safe and reliable operation, DMR20-1-ACV

AC voltage monitors must be installed and serviced by qualiﬁ ed

technical personnel. Contact Murata Power Solutions if there is

any doubt regarding installation or operation.

1. Measurement Type: DMR20-1-ACV series AC voltmeters employ a

precision true-rms signal conditioning IC, a 13-bit analog-to-digital

converter, and a stable voltage reference to measure and display 85 to

264Vac 50/60Hz AC supplies. DMR20-1-ACV voltmeters can be pow-

ered from—and accurately measure—AC supplies with sine, triangle,

square, and quasi-sine waveforms. High-frequency harmonic compo-

nents up to 65kHz will be measured with minimal additional error.

2. Calibration: DMR20-1-ACV voltmeters are factory calibrated; there are

no provisions for calibrating these meters in the ﬁ eld.

3. Operating Range: As the AC input voltage is lowered to 95.0Vac (50 or

60Hz) or below, the DMR20-1-ACV’s display will begin to dim slightly,

but it will remain accurate down to its 85Vac rating. Input voltages

above 265Vac will cause the display to ﬂ ash on and off at approxi-

mately one-second intervals.

4. Panel Installation: All electrical connections to DMR20-1-ACV must

be made after the voltmeter is securely attached to the panel, and with

the input AC supply de-energized (off). In high-vibration environments,

adequate strain reliefs must be used on all supply wiring. See Figure 1

for typical panel mounting details.

Tightening Torque:

The recommended tightening torque for the M30 x 1.5 plastic hex nut

is 10 to 17 in-lbs (1.3 to 1.9 N-m). If a torque wrench is not available,

this recommended range can be approximated by hand tightening the

hex nut SLOWLY until it just bottoms out against the panel’s rear sur-

face. From this bottomed-out reference position, using a suitable tool,

tightening the hex nut ¼ turn clockwise will produce approximately 10

in-lbs (1.3 N-m) of torque; tightening it 3/8 turn clockwise will produce

approximately 17 in-lbs (1.9 N-m).

Check to make sure the housing’s anti-rotation key is aligned with the

notches on both the panel and the gasket before tightening the hex

nut. Over tightening the hex nut will distort the rubber gasket and may

damage the threads on both the nut and the housing, thereby compro-

mising the installation’s mechanical integrity and its ability to protect

against environmental effects.

Panel Thickness:

When using both the factory supplied EPDM gasket and hex nut (the

recommended standard installation method), the DMR20-1-ACV can be

mounted in panels ranging from 0.032" to 0.250" (0.8 to 6.4mm) thick.

When the gasket is not used, the panel thickness range is 0.075" to

0.325" (1.9 to 8.3mm). However, using the factory supplied hardware

and tightening torque recommendations results in optimal resistance to

vibration, dust, and moisture ingress.

Panel Materials:

Acceptable panel materials include aluminum, mild steels, plastics,

FR-4 pc-board (ﬁ berglass), and many other materials with a ﬂ at matte

surface on both sides of the cutout. The DMR-20-x-KP tools can be

used with most panel materials except for stainless steel or other

hardened metals.

DMR20-1-ACV has passed vibration testing combined with temperature

cycling while mounted to the materials noted above, using the speci-

ﬁ ed tightening torques. If the voltmeter will be mounted to extremely

smooth, slippery surfaces, the user is advised to test the completed

assembly under the environmental conditions encountered in the end

application.

5. AC Input Fusing and Wiring: DMR20-1-ACV voltmeters contain an

internal, self-resettable fuse. However, the supply wires connected to

input terminals TB1-A and TB1-B must be fused with an external, user

supplied, 0.25A/300V time delay/time lag fuse, in accordance with

applicable regulatory codes.

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

conduct and comply with any code or application-mandated require-

ments pertaining to the user’s speciﬁ c installation. 300V, UL-rated

hook-up wire suitable for the intended application is required. TB1 is to

be used only for powering the meter’s internal circuitry; it must not be

used to supply power to external loads.

The recommended TB1 supply wire size is 18AWG to 22AWG (0.83mm2

to 0.33mm2) solid or 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). When using stranded wire, verify that there are no loose

or stray strands that could potentially cause a short circuit across the

AC supply input.

6. AC Input Polarity and Grounding: The AC supply inputs TB1-A and

TB1-B terminals are not polarity sensitive, that is, neither terminal is

designated as “AC LO” or “AC HI.” DMR20-1-ACV voltmeters do not

include, nor require, a connection to earth/chassis ground.

Figure 1. Panel Installation

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DMR20-1-ACV

Self-Powered,

85 to 264Vac, LED Display Line Monitor

MPM_DMR20-1-ACV.B01 Page 2 of 4

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MECHANICAL SPECIFICATIONS

Dimensions are in inches (mm).

Tolerances (unless otherwise speciﬁ ed):

.XX ± 0.02 (0.51)

.XXX ± 0.010 (0.254)

Angles ± 2˚

Components are shown for reference only.

1.50 (38.1)

1.08 (27.4)

1.18 (29.8)

0.655 (16.64)

0.55 (14)

0.080 (2.03)

0.10 (2.5)

0.062 (1.58)

0.100 (2.54)

1.210 (30.73)

AC VOLTS

TRUE RMS

TB1AB

Recommended panel cutout

3D models are available at www.murata-ps.com/en/3d/meters.html

1. Description of safety marks:

Caution, risk of electrical shock

Caution, risk of danger

Equipment is protected throughout by double or reinforced insulation

2. Cleaning Instructions: Gently clean with dry cloth only.

3. Caution: if the equipment is used in a manner not speciﬁ ed by Murata Power Solutions, the protection provided by the equipment may be impaired.

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DMR20-1-ACV

Self-Powered,

85 to 264Vac, LED Display Line Monitor

MPM_DMR20-1-ACV.B01 Page 3 of 4

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OSCILLOGRAMS

The graphs below show typical DMR20-1-ACV readings when the unit is powered from six common ac-voltage waveforms.

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Murata Power Solutions, Inc. makes no representation that the use of its products in the circuits described herein, or the use of other

technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein do not imply

the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Speciﬁ cations are subject to change without

Murata Power Solutions, Inc.

11 Cabot Boulevard, Mansﬁ eld, MA 02048-1151 U.S.A.

ISO 9001 and 14001 REGISTERED

This product is subject to the following operating requirements

and the Life and Safety Critical Application Sales Policy:

Refer to: http://www.murata-ps.com/requirements/

DMR20-1-ACV

Self-Powered,

85 to 264Vac, LED Display Line Monitor

MPM_DMR20-1-ACV.B01 Page 4 of 4

NANO