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 simpli 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 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- tionalno additional components or power sources are required. Performance/Functional Speci cations Their large, 0.30 /7.6mm, bright LED displays can be easily read from 10 feet away (3 Typical at Ta = +25C, unless otherwise noted meters). These auto-ranging meters accurately display DC voltages with 0.01V in the LO DC Input (TB1) Range (below 51V), or 0.1V resolution in the HI Range (above 51 V). A built-in resettable Input voltage range +6 to +75Vdc fuse assures long term reliability. All DMR20-10-DCMs employ a 13-bit A/D converter Current Consumption Vin = 75.0Vdc: 7mA (max.) and precision metal- lm resistors to achieve outstanding performance over an operating Reverse Polarity Protection -100Vdc (min.) temperature range of 25 to +60C. Performance The DMR20-10-DCM is housed in a rugged, round polycarbonate case that provides excel- Sampling Rate 2.5 readings/second lent protection against moisture, dust, shock and vibration. Panel installation is straightfor- Resolution 0.01Vdc in LO Range ward: using readily available tooling, simply drill and punch a 1.2 inch (30.5mm) diameter 0.1Vdc in HI Range Accuracy +25C hole and anti-rotation notch, insert the meter and gasket into the panel, and securely fasten 0.2V (typ.), 0.4V (max.) HI Range the meter using the supplied hex nut. The supplied hardware is designed to provide protec- LO Range 0.03V (typ.), 0.06V (max.) tion to IP67/NEMA 6. Overrange Indication See note 3 Temperature Drift 0.003V/C (typ.) Mechanical Dimensions 1.50 diameter x 1.08 dept Ordering Information (38.1 x 27.4mm) DMR20-10-DCM-R-C 6 to 75Vdc voltage monitor (Red LED) Display Type Four digit, LED, 0.30 high (7.6mm) Weight 0.6 ounces (18 grams) Tooling with nut and gasket DMR20-1-KP 1.2 (30.5mm) Round knockout punch Case Material Polycarbonate (no keying notch) Terminal Block Torque 3.6 in-lbs (0.4 N-m) DMR20-2-KP 2 1.2 (30.5mm) Round knockout punch Wire Size And Type 18-22AWG (0.83-0.33mm ) copper, (with four keying notches) solid or stranded DMR20-3-KP 1/8 and 3/16 (3.2 and 4.7mm) Wire Insulation Strip Length 0.25 (6.4mm) key-notch nibbler tool Environmental Note: An M30 x 1.5 nylon hex nut and EPDM sealing gasket are supplied with each meter. Operating Temperature 25 to +60C The -C suf x denotes RoHS compliance. Storage Temperature 40 to +75C Humidity (non-condensing) 0 to 85% Operation and accuracy at inputs above or below these ranges are not speci ed. 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. 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 ash on and completely For full details go to off at approximately one second intervals. Continuous operation above 80V will permanently www.murata-ps.com/rohs damage the meter and void its warranty. www.murata-ps.com/support MPM DMR20-10-DCM.A01 Page 1 of 4NANO DMR20-10-DCM 2-Wire, Self-Powered, Auto-Ranging DC Voltage Monitor TECHNICAL NOTES IMPORTANT To ensure safe and reliable operation, DMR20-10-DCM Panel Materials: DC voltage monitors must be installed and serviced by quali ed Acceptable panel materials include aluminum, mild steels, plastics, technical personnel. Contact Murata Power Solutions if there is FR-4 pc-board ( berglass), and many other materials with a at matte any doubt regarding installation or operation. 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 1. Operating Input Range: The unit is shipped with auto-range jumper hardened metals. JP1 in the open position. With JP1 open, auto-range operation is disabled and the unit will display input voltages between +6 to +75Vdc DMR20-10-DCM has passed vibration testing combined with tem- with a xed 0.1V resolution. Changes to JP1s con guration must only perature cycling while mounted to the materials noted above, using be made when the unit is off (de-energized). The unit will not recognize the speci ed tightening torques. If the voltmeter will be mounted to JP1 con guration changes made with power applied to TB1. extremely smooth or slippery surfaces, the user is advised to test the completed assembly under the environmental conditions expected in Closing jumper JP1 (see Figure 1) places the unit in the auto-range the end application. mode of operation. With auto-range enabled and Vin between +6V to +51V, the displayed resolution is 0.01V (i.e., the unit is in LO Range). 4. Input Fusing and Wiring: DMR20-10-DCM voltmeters contain an When the unit is in LO Range and Vin is increased to +51V, it will auto- internal, self-resettable fuse. However, the supply wires connected to range to the HI range and display 0.1V resolution. When the unit is in input terminals TB1s + and terminals must be fused with an HI range and Vin drops below +49V, it will auto-range back to the LO external, user supplied, 0.25A/300V time delay/time lag fuse, in accor- Range and display 0.01V resolution. dance with applicable regulatory codes. Operation below +6Vdc will produce a noticeably dimmer display and All supply wiring must be rated for the voltages and currents they will accuracy is not guaranteed. Continuous operation between +75 and conduct and comply with any code or application-mandated require- +80Vdc, while not recommended, will not adversely affect the unit. See the ments pertaining to the users speci c installation. 300V, UL-rated Performance/Functional Speci cations section for more information. hook-up wire suitable for the intended application is required. TB1 is to be used only for powering the meters internal circuitry it must not be 2. Calibration: DMR20-10-DCM voltmeters are factory calibrated there used to supply power to external loads. are no provisions for calibrating these meters in the eld. 2 The recommended TB1 supply wire size is 18AWG to 22AWG (0.83mm 3. Panel Installation: All electrical connections to DMR20-10-DCM must 2 to 0.33mm ) solid or stranded copper wire. The supply wires must be be made after the voltmeter is securely attached to the panel, and with properly stripped and attached to TB1 such that their insulation is not the input DC input supply source de-energized (off). In high-vibration pinched by the screw terminal. Recommended insulation strip length is environments, adequate strain reliefs must be used on all supply 0.25 (6.4mm). When using stranded wire, verify that there are no loose wiring. See Figure 2 for typical panel mounting details. or stray strands that could potentially cause a short circuit across the Tightening Torque: DC supply input. The recommended tightening torque for the M30 x 1.5 plastic hex nut 5. Input Polarity: The input terminal block TB1 is polarity sensitive, and is 10 to 17 in-lbs (1.3 to 1.9 N-m). If a torque wrench is not available, connections to it must be made as shown in the Mechanical Speci ca- this recommended range can be approximated by hand tightening the tions section of this data sheet. However, intermittent or continuous hex nut SLOWLY until it just bottoms out against the panels rear sur- application of reverse-polarity voltages up to 100V will not damage face. From this bottomed-out reference position, using a suitable tool, the meter. tightening the hex nut 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 housings 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 installations 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 DMR20-10-DCM 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 Figure 1. JP1 con gured for auto-range operation resistance to vibration, and dust and moisture ingress. www.murata-ps.com/support MPM DMR20-10-DCM.A01 Page 2 of 4