3020-01100-0

www.murata-ps. com To Be Discontinued Murata Power Solutions’ 50mV and 100mV base-mounted current shunts are designed for measuring dc currents from 5A to 1200A. These precision shunts (+/–0.25% accuracy) connect directly to MPS’s DCA5-20PC Series of dc ammeters. Installation is straightforward: simply connect the load circuit to the shunt’s threaded studs and the shunt’s mV Kelvin-outputs to the digital ammeter’s input terminals. 50mV and 100mV Base-mounted NOTE: See the table on the back page for recommended substitutes for discontinued Murata shunt resistors MPS Part Number All models feature a rugged phenolic base that provides 750V isolation to the shunt’s brass terminals, allowing for direct attachment to metal surfaces. A highly stable (+/–15ppm/°C) manganin sensing-element provides a wide –40 to +60°C operating temperature range. Please see the DCA5-20PC data sheet for additional ammeter-related information and detailed connection diagrams. General Specifications (All Models) Rated Accuracy ±0.25% max. Sensing Element Manganin Terminal Posts/ Screws Brass Tightening Torgue See Mechanical Dimensions Current Rating See Selection Guide Operating Temperature –40 to + 60°C (–40 to +137°F) DMS Accessories Product Status 3020-01097-0 Discontinued 3020-01107-0 Discontinued 3020-01098-0 Discontinued 3020-01096-0 Discontinued 3020-01099-0 Discontinued 3020-01108-0 Discontinued 3020-01100-0 Discontinued 3020-01101-0 Discontinued 3020-01102-0 Discontinued 3020-01103-0 Discontinued 3020-01104-0 Discontinued 3020-01105-0 Discontinued 3020-01106-0 Discontinued Technical Notes IMPORTANT! To ensure safe and reliable operation, dc shunts and all associated equipment must be installed and serviced by qualified technical personnel. Never make any connections to the shunt, the load, or the ammeter with energized power sources. Contact Murata Power Solutions if you have any questions regarding the installation or operation of any of our instruments and accessories. 1. Base-Mounted Shunt Precautions: DC current shunts are low value resistors that develop a mV output when current passes through their highly-stable manganin resistive element. Under high current, continuous use operation, dc shunts will dissipate considerable power and may undergo a significant temperature rise. For example, if allowed to operate continuously at its full rated load, a 500A/50mV shunt dissipates 25 Watts (500A x 0.050V = 25 Watts). Therefore, whenever possible, be sure to specify 50mV shunts due to their inherently lower power dissipation and voltage drop. To ensure that the manganin sensing element does not exceed 125°C under worst case operating conditions, please read and follow the guidelines in the mounting and derating sections of this data sheet. Tighten all connections on the shunt per the torque specifications given in the mechanical dimensions and selection guide on page 3. Please note, the user is responsible for selecting the correct wire sizes (gauge) and wire type for the given application. 2. Mounting Considerations: All shunts should be mounted with their resistance blades in a vertical position to allow for natural convection cooling (see Figure 1). Forced-air cooling must be provided when vertical mounting is impractical, or in installations where the shunt is installed in a confined location. The shunt’s manganin blades must never be allowed to exceed +125°C; doing so will cause permanent damage to the shunt. Shunts must be installed in a manner that protects them from damage due to thermal expansion forces produced by high- or For full details go to www.murata-ps.com/supMPM_DMS Accessories.D03  Page 1 of 4 DMS Accessories 50mV and 100mV Base-mounted or pulsed (intermittent) currents. Mount shunt on a vertical surface 50A 50mV LOAD CURRENT 5. Temperature Derating: If the shunt is to be operated at ambient temperatures above +25°C, the maximum continuous current must be further derated from the 2/3 value previously noted. 50mV OUTPUT Where Ie = Maximum permissible continuous current at elevated temperature Te Pe = Maximum power dissipation at the elevated temperature Te R = Shunt’s resistance (see selection guide for values) Pa = 0.667 x shunt’s rated power at 25°C ambient Te = Elevated temperature Ipuls = Ppuls/R, and Ppuls = Pa/K1, andK1 = D Example: How much current can a 150 Amp 50mV shunt safely carry at an ambient temperature of +100°C? Figure 1. Typical installation short-circuit currents. In most cases, shunts are weaker than their external-circuit connections, so provisions for additional wiring-flexibility may be required in high current and/or highvibration applications. Whenever practical, all shunts should be connected in the grounded side (normally the ‘chassis’) of the dc supply. However, these shunts must be connected in the grounded side of the circuit when the dc supply exceeds 750 volts (the rated limit for the shunt’s phenolic insulating base). When more than one wire is to be connected to each end of a shunt, the wires must be evenly distributed between both terminals (see Figure 1). 3. Lead Extensions: The shunt’s Kelvin outputs (i.e., their 50mV or 100mV output signal) should not exceed 24 inches in length (61cm), assuming 22AWG (0.5mm2) wire is used. If longer leads are necessary, the additional voltage drops in the leads must be taken into consideration as they will degrade accuracy and stability. However, MPS’s DCA5 series dc ammeters feature a calibration potentiometer that can be used to Pe long leads are compensate for some additional losses Ie =when R employed; contact MPS for calibration information. 4. Continuous-Operation Derating: If continuous operation is required, a shunt must only be allowed to carry 2/3 of its maximum nameplate amperage. The 2/3 derating factor provides an adequate safety margin for convection cooled shunts operating in an ambient temperature of +25°C. The following two sections contain additional derating that is required when shunts will be exposed to higher operating temperatures To find the maximum permissible continuous current (Ie) at an Pe elevated temperature (Te), Ie oneRmust first calculate the maximum allowable power dissipation (Pe) at Te, using the following formulas: 1.25W Ie = 0.00033Ω = 61.5A Pe = Pa x [1-(Te-25°C)/100°C], and Te = +100°C Pa = 0.667(150A x 0.050V) = 5.0 Watts Pe = 5.0W[1-(100-25)/100] = 5.0W x (1-0.75) = 1.25W R = 0.00033 Ohms Lastly, use the formula to find the maximum derated continuous-current at Te = +100°C: 6. Intermittent (Pulsed) Operation: Shunts that will not be exposed to continuous operation at 2/3 rated current can be operated at K1 = 0.25 levels close to, or even above, their nameplate ratings for portions of short periods of times (5 minutes maximum) at 25°C ambient. The following 53.4W formulas can be used to calculate the maximum Ipulsed = 0.0000625Ω = 924A www.murata-ps.com/supMPM_DMS Accessories.D03  Page 2 of 4 J3 J3 MUST BE INSTALLED DMS Accessories 50mV and 100mV Base-mounted 0-50mV OUTPUT 0-50mV OUTPUT – – + – LOAD + + DC SUPPLY + + – 50mV SHUNT 50mV SHUNT LOAD CURRENT LOAD CURRENT R3 – DC SUPPLY R7 ON POWER GROUND (0Vdc) Figure 2. Typical Low-Side Shunt Connections + ZERO – ADJUST LOAD 1 2 3 POWER GROUND (0Vdc) 4 5 DIP SWITCHES 6 Figure 3. Typical High-Side Shunt Connections CURRENT TO VOLTAGE CONVERTER MECHANICAL SPECIFICATIONS 1/4-28 UNF Hex Jam Nut 1/4 UNF Stud 5 through 150 Amps Part No. Rated Current/ Output Resistance (Ωs at 25˚C) 3020-01097-0 5A/50mV 3020-01107-0 0.62 (15.7) Torque Range 1.68 0.50 (42.7) (12.7) 0.01 36-40 in-lbs (4.14.5Nm) 0.56 (14.2) 10A/100mV 0.01 36-40 in-lbs (4.14.5Nm) 3020-01098-0 20A/50mV 0.0025 36-40 in-lbs (4.14.5Nm) 3020-01096-0 50A/50mV 0.001 36-40 in-lbs (4.14.5Nm) 0.20 (5.08) Dia. 0.50 (12.7) 0.87 1.25 (22.0) (31.7) 1.00 (25.4) 8-32 Screw 2.00 (50.8) 50mV SHUNT 3/8-16 x 5/8 8-32 Screw 0.43 (10.9) 200 through 500 Amps 0.75 (19.0) Part No. Rated Current/ Output Resistance (Ωs at 0.56 (14.2) 25˚C) 3020-01101-0 200A/50mV 0.00025 14-15 ft-lbs (19.020.3Nm) 3020-01102-0 300A/50mV 0.000167 14-15 ft-lbs (19.020.3Nm) Torque Range 1.75 (44.4) 0.56 (14.2) 0.20 (5.08) Dia. 0.62 (15.7) 0.62 (15.7) 1.75 (44.4) 1.5 (38.1) 3.25 (82.5) 50mV SHUNT www.murata-ps.com/supMPM_DMS Accessories.D03  Page 3 of 4 DMS Accessories 50mV and 100mV Base-mounted MECHANICAL SPECIFICATIONS (continued) 1/2-13 x 7/8 8-32 Screw 0.53 (13.5) 800 through 1200 Amps Part No. Rated Current/ Output Resistance (Ωs at 25˚C) 3020-01104-0 800A/50mV 0.56 (14.2) 0.0000625 1.00 (25.4) Torque Range 2.16 (54.9) 0.62 (15.7) 32-35 ft-lbs (43.447.5Nm) 0.20 (5.08) Dia. 1.00 (25.4) 2.5 (63.5) 1.00 (25.4) 2.16 (54.9) 4.5 (114.3) 50mV SHUNT Recommended Substitute Parts MPS Part Number Canadian Shunt Industries Hoyt Electrical Instrument Works Riedon 3020-01097-0 LA-5-50 LA-5-50 RSA-5-50 3020-01107-0 LA-10-100 LA-10-100 RSA-10-100 3020-01098-0 LA-20-50 LA-20-50 RSA-20-50 3020-01096-0 LA-50-50 LA-50-50 RSA-50-50 3020-01099-0 LA-100-50 LA-100-50 RSA-100-50 3020-01108-0 LA-100-100 LA-100-100 RSA-100-100 3020-01100-0 LA-150-50 LA-150-50 RSA-150-50 3020-01101-0 LB-200-50 LB-200-50 RSB-200-50 3020-01102-0 LB-300-50 LB-300-50 RSB-300-50 3020-01103-0 LB-500-50 LB-500-50 RSB-500-50 3020-01104-0 LC-800-50 LC-800-50 RSC-800-50 3020-01105-0 LC-1000-50 LC-1000-50 RSC-1000-50 3020-01106-0 LC-1200-50 LC-1200-50 RSC-1200-50 Murata Power Solutions, Inc. 11 Cabot Boulevard, Mansfield, 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 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. Specifications are subject to change without notice. www.murata-ps.com/supMPM_DMS Accessories.D03  Page 4 of 4