Schneider Electric RUMC31B7 RUM Relay 24 V AC

RUMC31B7 RUM universal plug-in relay and its part number

RUMC31B7 is an RUM universal plug-in relay from the Schneider Electric Harmony Electromechanical Relays range. Its datasheet lists 3 C/O contacts, an AC coil rated 24 V AC 50/60 Hz, and no status LED. Mounting is plug-in, with cylindrical pins.

Reading the code from the datasheets of this family: RUMC3 = RUM series universal relay with three changeover contacts; the digit after it (1 or 2) separates the versions without and with LED, and the suffix B7 identifies the coil, here 24 V AC 50/60 Hz. This reading follows how the sibling datasheets line up and is not an ordering table, so verify the full code against the manufacturer catalogue when it matters.

Seven Star LLC supplies RUMC31B7 in Oman and the GCC as an independent supplier in Muscat. The datasheet we hold is dated 8 Nov 2026.

Contact ratings and switching limits

Contact data for RUMC31B7: maximum switching capacity 2500 VA/280 W, minimum switching capacity 170 mW at 10 mA, 17 V; contact material AgNi.

Rated operational current entries:

• 10 A at 277 V AC conforming to UL
• 10 A at 30 V DC conforming to UL
• 10 A at 277 V AC (same polarity) conforming to CSA
• 10 A at 30 V DC conforming to CSA
• 5 A at 250 V AC (NC) conforming to IEC
• 5 A at 28 V DC (NC) conforming to IEC
• 10 A at 250 V AC (NO) conforming to IEC
• 10 A at 28 V DC (NO) conforming to IEC

Durability: 100000 cycles for resistive load. Derate for inductive or DC loads and follow the curves in the datasheet.

Coil circuit and supply window of RUMC31B7

The coil of RUMC31B7 is rated 24 V AC 50/60 Hz with voltage limits of 19.2–26.4 V AC. The datasheet gives an average coil resistance of 72 Ohm at 20 °C ± 15 % and average consumption of 3 at 60 Hz VA. The relay releases when the control voltage falls to ≥ 0.15 Uc AC, which is the figure to compare against any sagging control supply or leakage from a PLC output.

Operating and reset times are stated as 20 ms at nominal voltage. There is no LED on this version.

A 24 V AC coil normally comes from a control transformer; confirm the transformer rating covers the coil load of every relay on it and that the secondary is fused.

Sockets and related parts for RUMC31B7

Sockets documented for RUM relays with 3 C/O contacts are RUZC3M (mixed contact, 10 A, 38 mm) and RUZSC3M (separate contact, 12 A, 36 mm).

The same series also includes the following parts, which share the basic body of RUMC31B7 but differ as shown:

• Against RUMC31F7: coil 24 V AC 50/60 Hz against 120 V AC 50/60 Hz on RUMC31F7.
• Against RUMC31P7: coil 24 V AC 50/60 Hz against 230 V AC 50/60 Hz on RUMC31P7.
• Against RUMC32BD: coil 24 V AC 50/60 Hz against 24 V DC on RUMC32BD; no LED against an LED on RUMC32BD; drop-out ≥ 0.15 Uc AC against ≥ 0.1 Uc DC on RUMC32BD.
• Against RUMC32P7: coil 24 V AC 50/60 Hz against 230 V AC 50/60 Hz on RUMC32P7; no LED against an LED on RUMC32P7.

Because the differences are in the coil or contact details, the complete part number must be confirmed before ordering.

Installation, commissioning and maintenance

Plug the relay into its socket with the supply isolated. The datasheet for RUMC31B7 lists IP rating IP40 and an ambient range of -40–55 °C for operation. Route coil wiring away from contact wiring where possible, to limit coupling between the two circuits.

During commissioning, energise the coil at its nominal voltage, check contact transfer with a meter, and verify that the supply stays inside the voltage limits. In service, inspect for discoloured pins, replace relays that show contact wear, and keep a spare on the shelf for critical interlocks.

Typical use of RUMC31B7 in Oman and the GCC

Typical installations are marshalling and interface panels in desalination, power and petrochemical plants, plus building services, where a replaceable relay keeps maintenance quick. Heat inside sun-exposed cabinets and salt-laden coastal air are the main points to design for; the datasheet lists pollution degree 2 and IP rating IP40.

RUMC31B7 suits panels that need 3 C/O switching with no status LED and a lockable test button, and where the supply is 24 V AC 50/60 Hz.

RUMC31B7 technical specifications

Family comparison and RFQ details

For a quotation on RUMC31B7 please send the exact part number, quantity, coil voltage, delivery location in Oman or the GCC and any project reference. If your drawing lists a different coil voltage, say so and we will check the matching variant.

Selection and ordering checklist for RUMC31B7

Before ordering RUMC31B7 confirm:

• Control voltage: 24 V AC 50/60 Hz (19.2–26.4 V AC); AC and DC versions are not interchangeable.
• Contact load: check the load against 2500 VA/280 W and the current table above.
• Indicator needs: this version is without a status LED.
• Socket type and terminal style matching the relay pins.
• Quantity and whether a spare relay should be held for the plant.

Documents and quotation

The datasheet for this unit is attached to this page (document dated 8 Nov 2026). Please treat it as the reference for every figure above, and tell us if your project specification asks for anything the datasheet does not state.

Send the part number, quantity, required delivery point and any project reference through the quotation form or by email. Seven Star LLC is an independent industrial supplier based in Muscat, serving customers across Oman and the GCC, and we reply with availability and lead time for this exact part number.