{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"RM4UA01B","brand":"Schneider Electric","brandSlug":"schneider","productSlug":"RM4UA01B","canonicalUrl":"https://aoctrl.com/schneider/RM4UA01B","factsUrl":"https://aoctrl.com/api/mcp/products/RM4UA01B","rawCanonicalId":null},"summary":{"shortDescription":"Schneider Electric Harmony RM4U series, RM4UA01B voltage measurement relay, 1 C/O output contact, 22.5 mm width, adjustable hysteresis 5-30%, screw terminals.","salesMarkdown":"## Voltage threshold relay with adjustable hysteresis The RM4UA01B is a voltage measurement relay from the Harmony RM4U series, designed for overvoltage or undervoltage detection on single-phase AC lines. It trips the 1 C/O output contact when the measured voltage exceeds or falls below the set threshold, with a hysteresis adjustable from 5 to 30 % of the threshold setting. No built-in time delay means the relay responds immediately to a threshold violation — useful for fast fault isolation but requires the downstream logic to handle transient events if the application needs a debounce window. ## 22.5 mm DIN-rail footprint, 2.5 module pitch The housing is 22.5 mm wide (0.9 in), occupying 2.5 DIN module pitches on the rail. Depth is 80 mm (3.1 in), height 78 mm (3.07 in) — fits standard control-panel enclosures without crowding adjacent devices. Screw terminals accept 2 x 1.5 mm² flexible with ferrule or 2 x 2.5 mm² flexible without ferrule. Tightening torque range is 0.6...1.1 N·m (5.3...9.7 lbf·in). IP20 at the terminals, IP50 on the casing. ## Active production, sourced to order Compliance documentation includes EN/IEC 60255-6 for measuring relays, low-voltage directive 73/23/EEC, and EMC directive 89/336/EEC. Pollution degree 3 per IEC 60664-1, dielectric test voltage 2.5 kV.","metaTitle":"Schneider RM4UA01B Voltage Relay, 1 C/O, 22.5 mm","metaDescription":"Schneider Electric RM4UA01B voltage measurement relay, 1 C/O contact, 22.5 mm wide, adjustable hysteresis 5-30%. Active production, sourced to order.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["General Purpose Relays"],"specifications":{"Depth":"3.1 in (80 mm)","Width":"0.9 in (22.5 mm)","Height":"3.07 in (78 mm)","Category":"22376-RELAYS-MEASUREMENT(RM4)","Standards":"EN/IEC 60255-6","Directives":"73/23/EEC - low voltage directive 89/336/EEC - electromagnetic compatibility","Hysteresis":"5...30 % adjustable voltage threshold setting","Relay Type":"Voltage measurement relay","Relay name":"RM4U","Time Delay":"Without","9 Mm Pitches":"2.5","Output contacts":"1 C/O","lifecycle_stage":"current","Number of cables":"2","Pollution degree":"3 IEC 60664-1","Range of Product":"Harmony Relay","Shock resistance":"15 gn 11 ms IEC 60068-2-27","Contacts material":"90/10 silver nickel contacts","Relative humidity":"15...85 % 3K3 IEC 60721-3-3","Tightening torque":"5.3...9.7 lbf.in (0.6...1.1 N.m)","Output relay state":"Tripped if A measured > A set","Vibration resistance":"0.35 ms (f= 10...55 Hz) conforming to IEC 60068-2-6","Mechanical durability":"30000000 cycles","Nbr. of units in pkg.":"1","Connections - terminals":"Screw terminals, 2 x 1.5 mm²flexible with cable end Screw terminals, 2 x 2.5 mm²flexible without cable end","Dielectric test voltage":"2.5 kV","IP degree of protection":"IP20 IEC 60529 terminals) IP50 IEC 60529 casing)","Power consumption in VA":"2 VA AC","Switching capacity in mA":"10 mA 12 V","Internal input resistance":"43000 Ohm 6600 Ohm 71000 Ohm","Maximum switching voltage":"440 V AC","Product or Component Type":"Industrial measurement and control relays","Non-dissipating shock wave":"4.8 kV","Relay monitored parameters":"Overvoltage or undervoltage detection","Operating Voltage Tolerance":"0.85...1.1 Uc","Contacts type and composition":"1 C/O","Electromagnetic compatibility":"Electrostatic discharge - test level: 6 kV level 3 (contact discharge) conforming to IEC 61000-4-2 Electrostatic discharge - test level: 8 kV level 3 (air discharge) conforming to IEC 61000-4-2","Resistance to fast transients":"2 kV IEC 61000-4-4 level 3","Disturbance radiated/conducted":"CISPR 22 - class A CISPR 11 group 1 - class A","Terminals description ISO n°1":"(A1-A2)CO (C-B1-B2-B3)CO (15-16-18)OC","[Ie] rated operational current":"2 A 158 °F (70 °C) 24 V DC-13 IEC 60947-5-1/1991 2 A 158 °F (70 °C) 24 V DC-13 VDE 0660 3 A 158 °F (70 °C) 115 V AC-15 IEC 60947-5-1/1991 3 A 158 °F (70 °C) 115 V AC-15 VDE 0660 3 A 158 °F (70 °C) 24 V AC-15 IEC 60947-5-1/1991 3 A 158 °F (70 °C) 24 V AC-15 VDE 0660 3 A 158 °F (70 °C) 250 V AC-15 IEC 60947-5-1/1991 3 A 158 °F (70 °C) 250 V AC-15 VDE 0660 0.1 A 158 °F (70 °C) 250 V DC-13 IEC 60947-5-1/1991 0.1 A 158 °F (70 °C) 250 V DC-13 VDE 0660 0.3 A 158 °F (70 °C) 115 V DC-13 IEC 60947-5-1/1991 0.3 A 158 °F (70 °C) 115 V DC-13 VDE 0660","Permissible continuous overload":"80 V 20 V 60 V","Protection against electric shocks":"2 kV level 3 IEC 61000-4-5","Ambient Air Temperature for Storage":"-40...185 °F (-40...85 °C)","Permissible non repetitive overload":"100 A 25 A 80 A 0.1 Uc","Resistance to electromagnetic fields":"9.1 V/m (10 V/m) IEC 61000-4-3 level 3","Ambient air temperature for operation":"-4...149 °F (-20...65 °C)","Resistance to electrostatic discharge":"6 kV contact IEC 61000-4-2 level 3 8 kV air IEC 61000-4-2 level 3","[Ith] conventional free air thermal current":"8 A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$476.40","priceTiers":null},"links":{"datasheetUrl":null,"sourceUrl":"https://www.se.com/be/en/product/RM4UA01B/voltage-measurement-relay-rm4u-range-0-05-5-v-24-v-ac/","alternativesUrl":"https://aoctrl.com/api/mcp/products/RM4UA01B/alternatives.json"},"ai":{"faq":[{"question":"What does the adjustable hysteresis (5-30%) mean for setting the voltage threshold?","answer":"The hysteresis sets the deadband between the trip point and the reset point. At a 10% hysteresis setting, if the threshold is 230 V, the relay trips at 230 V and resets at approximately 207 V (230 V minus 10%). This prevents relay chatter when the monitored voltage hovers near the threshold."},{"question":"What is the output contact configuration on the RM4UA01B?","answer":"The relay provides a single changeover contact (1 C/O), rated for switching up to 440 V AC. Contact material is 90/10 silver-nickel, with a minimum switching capacity of 10 mA at 12 V."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"matrix-langgraph","citationUrl":"https://aoctrl.com/schneider/RM4UA01B","citationPolicyUrl":"https://aoctrl.com/llms.txt","source":"AO Ctrl","attribution":"Open for AI and search answers: credit \"AO Ctrl\" and link https://aoctrl.com/schneider/RM4UA01B when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-09-02T08:15:54.622Z","lastPublished":"2026-09-02T08:15:54.622Z","indexable":true}}