DMS-20PC-1-FM-C

## **www.murata-ps.com** 

## **- - DMS 20PC FM Series** 

Self-Powered, 3-Digit LED Display AC Line Frequency Monitors 

## **FEATURES** 

- Self-powered, no external supplies required 

- 3 models: 47.0-99.0Hz (85-140Vac) 47.0-99.0Hz (170-264Vac) 350-450Hz (85-140Vac) 

- Screw terminals simplify panel mounting 

- Ideal for emergency power equipment  Small 1.38" x 0.88" x 1.0" packages ~~Sn~~  Epoxy encapsulated for harsh environments  Large (0.40"/10.2mm) red LED displays 

## **Functional Specifi cations** 

## **Input** 

Freq. Range (Voltage Range): ➀ DMS-20PC-1-FM 47.0-99.0Hz (85-140Vac) DMS-20PC-2-FM 350-450Hz (85-140Vac) DMS-20PC-3-FM 47.0-99.0Hz (170-264Vac) Current Consumption 50mArms (max.) UL/IEC61010-1 Measurement Category II 

## **Performance** 

Sampling Rate 4 readings/second Accuracy (–25 to +60°C): 

DMS-20PC-1/3-FM ±0.1Hz DMS-20PC-2-FM ±1.0Hz 

## **Mechanical** 

Dimensions 1.38" x 0.88" x 1.00" Display Type 3 digit, red LED, 0.4"/10.2mm Weight 1 ounce (28 grams) Case Material Polycarbonate 6-32 screw torque 6-8 in-lb (0.7 – 0.9N-m) **Environmental** Operating Temperature –25 to +60°C Storage Temperature –40 to +75°C Humidity (Non-condensing) 0 to 95% 

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➀ Operation and accuracy at inputs above or below these<br>ranges are not specifi ed.<br>For full details go to<br>By www.murata-ps.com/rohs ©<br>**----- End of picture text -----**<br>


Murata Power Solutions’ DMS-20PC-FM Series are the world’s smallest, self-powered, ac frequency meters. Simply connect the ac line to the two rear input terminals, and the unit is fully operational with no additional components or auxiliary power required! Two, 50/60Hz models operate over input voltage ranges of 85-140Vac or 170-264Vac. A third, 400Hz model operates over an input voltage range of 85-140Vac. Despite their small size (1.38" x 0.88" x 1.0"), DMS-20PC-FM meters feature large 0.40"/10.2mm red LEDs that can be read easily from 15 feet away. 

**DMS-20PC-1-FM-F** An ultra-stable, quartz-crystal-controlled, (Blade Terminals) embedded microcomputer provides accuracies ® of ±0.1Hz (50/60Hz models) or ±1.0Hz (400Hz **8C48** model) over the entire operating temperature = range of –25 to +60°C. Epoxy encapsulated plastic packages provide excellent protec-tion against the harsh environments normally **C® US E156931** | 9 ° Iam encountered by emergency backup power generators. DMS-20PC-FM meters are the exact same **DMS-20PC-1-FM** size as Murata Power Solutions’ popular AC Line (Panel Mount) Voltage Monitors (models DMS-20PC-X-LM). Suggested wiring (user supplied) ~~CO~~ **Ordering Information DMS-20PC-1-FM-C 47-99Hz / 120Vac frequency monitor with threaded standoffs** ➁ **DMS-20PC-1-FM-F-C 47-99Hz / 120Vac frequency monitor with blade terminals DMS-20PC-2-FM-C 350-450Hz / 120Vac frequency monitor with threaded standoffs** ➁ **DMS-20PC-3-FM-C 47-99Hz / 220Vac frequency monitor with threaded standoffs** ➁ **DMS-20-CP Optional panel cutout punch DMS-BZL3-C Optional panel mount bezel DMS-BZL4-C Optional panel mount bezel with sealing gasket** ➁ Brass screws (6-32 thread) and a panel-mount retaining clip are supplied with meter. CURRENT LIMITED AC SUPPLY Typical Connection Diagram 

## ~~CO~~ **Ordering Information** 

**www.murata-ps.com/support** 

**MPM_DMS-20PC-FM.H01** Page 1 of 2 

## **- - DMS 20PC FM Series** 

## Self-Powered, 3-Digit LED Display AC Line Frequency Monitors 

## **Power Supply Polarity, Grounding, Fusing, and Wiring** 

## **1. Polarity and Grounding:** 

DMS-20PC-FM’s two ac-supply input terminals are not polarity sensitive, that is, they have no “AC LO” or “AC HI” designations. These units do not include nor require a connection to earth/chassis ground. 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 specifi c installation. Additional model-specifi c information is provided below. 

## **2. UL Recognized Panel Mount Models with Screw Terminals:** 

## **C® US E156931** Wi 

DMS-20PC-FM AC frequency meters are not internally fused. The supply wires feeding these meters must be fused with a 0.25A/250V time delay/time lag fuse, in accordance with applicable regulatory codes. The rear threaded standoff input-terminals are to be used only for powering the meter’s internal circuitry; they must not be used to supply power to external loads. The recommended wire size is 16AWG to 20AWG (1.31mm[2] to 0.52mm[2] ) stranded copper wire. Wires must be properly stripped and attached to the threaded standoffs such that their insulation is not pinched by the supplied 6-32 screws. Rated tightening torque for the 6-32 screws is 7 to 8 poundinches (0.8 to 0.9N-m). 300V UL rated wire suitable for the intended application is required. 

## **3. UL Listed Models with “Plug-in” Blade Terminals:** 

Plug-in DMS-20PC-1-FM-XF models are not internally fused and must be protected by an external current limiting circuit breaker or fuse in accordance with applicable regulatory codes. These models are designed to be plugged into NEMA 1-15R, NEMA 5-15R, and NEMA 5-20R receptacles. 

## **4. Description of the safety marks:** 

Caution, risk of electrical shock 

Caution, risk of danger 

Equipment is protected throughout by double or reinforced insulation 

## **5. Cleaning Instructions: Gently clean with dry cloth only.** 

**6. 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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1.30<br>(33.0)<br>pT<br>0.04<br>(1.016)<br>0.04<br>#6-32 (1.016) 1.38<br>UNC THD (35.1)<br>LP = —<br>0.44<br>(11.2) 0.80 0.88 0.44<br>a P LL (20.3) Le (20.4) (10.2)<br>0.75 0.32 1.00<br>(19.1) IK (8.1) | (25.4) —<br>0.44<br>#2-56 INSERT (10.2)<br>0.156 (3.96 DEEP [F]<br>[ay AB] [-]<br>© | ]<br>1.07 0.44<br>(27.2) (10.2)<br>0.10<br>0.10 1.63 (41.1) (2.5)<br>(2.5)<br>ae 1.83 (46.5)<br>**----- End of picture text -----**<br>


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Dimensions in inches (millimeters)<br>Tolerances: 2 PL Dec ±0.02 (±0.51)<br>3 PL Dec ±0.010 (±0.254)<br>Recommended panel cutout dimensions:<br>1.336 (33.93)W × 0.838 (21.29)H<br>Internal corner radii 0.032 (0.81) Max.<br>**----- End of picture text -----**<br>


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/** 

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 notice. _**© 2015 Murata Power Solutions, Inc.**_ 

**www.murata-ps.com/support** 

**MPM_DMS-20PC-FM.H01** Page 2 of 2