Schneider Electric RM35TM250MW RM35-TM motor relay

RM35TM250MW: RM35TM motor temperature control relay in the Harmony range

The RM35TM250MW is a Schneider Electric Harmony motor temperature control relay from the RM35 family, built to supervise phase failure detection, phase sequence and motor temperature via PTC probe, plus a test/reset button and selectable memory behaviour. It is powered from a separate 24–240 V AC/DC 50/60 Hz supply, offers 2 normally open output contacts, and is housed in a 35 mm wide DIN-rail case. Seven Star LLC supplies the RM35TM250MW in Oman and the GCC as an independent supplier based in Muscat.

The datasheet we reviewed is dated 7 Nov 2026. It describes a unit with a test button on the front panel.

Installing and commissioning the RM35TM250MW

The relay clips onto a 35 mm DIN rail. The datasheet lists the operating position as Any position without derating. Terminals are screw type: Screw terminals, 1 × 0.5–1 × 4 mm² (20 AWG–11 AWG) solid without cable end; Screw terminals, 2 × 0.5–2 × 2.5 mm² (20 AWG–14 AWG) solid without cable end. Tightening torque is 0.6–1 N.m conforming to IEC 60947-1.

Before energising the RM35TM250MW, check the nameplate range against the supply and compare the wiring with the diagram on the datasheet and on the side of the housing. Switch on and confirm the green supply LED and the output indication. Then provoke the monitored fault in a safe way, for example by removing a fuse on a spare circuit or by simulating the condition, and confirm that the output behaves as intended. The test and reset button can help here.

What the RM35TM250MW monitors

According to the datasheet, this relay covers the following functions. Each one is explained in practical terms below.

• Phase failure detection. When a phase falls below the detection level the relay releases its output. This protects three-phase loads from running on two phases, a condition that overloads the remaining windings quickly.
• Phase sequence. The relay checks that L1, L2 and L3 arrive in the expected rotation. A reversed sequence makes pumps, compressors, fans and conveyors run backwards, which can damage equipment, so the output stays de-energised until the order is correct.
• Test and reset button. A front button lets the installer simulate a trip and clear the output, which makes commissioning and periodic checks quicker.
• Motor temperature via PTC probe. Thermistors in the motor windings raise their resistance sharply near their reference temperature. The relay trips when the loop resistance passes the tripping threshold and resets when it falls below the reset threshold, so a cooled motor can be released again.
• Memory selection. The fault state can be latched until a manual reset or follow the supply automatically, depending on the setting chosen. Latching is useful when a trip must be investigated before a machine is released.

Technical specifications of the RM35TM250MW

Environment, insulation and approvals for the RM35TM250MW

Storage is listed at -40 to 70 °C. Operation is listed at -20 to 50 °C. Relative humidity is 95 % at 55 °C conforming to IEC 60068-2-30. Protection is IP20 (terminals) conforming to IEC 60529, pollution degree 3 conforming to IEC 60664-1, rated insulation voltage 400 V conforming to IEC 60664-1. The housing is polycarbonate.

Certifications listed on the datasheet for this reference: CSA, C-Tick, GOST, UL, GL. Check the marks against your project specification, because requirements differ between sites.

In a closed panel in an Omani summer the air near the relay can be much hotter than the room, so leave space around it and keep it away from contactors and power resistors.

Output contacts and durability of the RM35TM250MW

The output is 2 normally open contacts, rated 5 A nominal at up to 250 V AC, with a switching capacity of 1250 VA and a minimum switching current of 10 mA at 5 V DC. The listed durability is 100000 cycles electrical and 30000000 cycles mechanical. The contacts of the RM35TM250MW are intended for pilot duty such as contactor coils, signal lamps and PLC inputs. For larger loads use an interposing contactor and keep the relay contact for the control circuit.

Because the minimum switching current is small, the same output can also feed a low-level signal such as a PLC input, but a contact that has switched heavy inductive loads should not later be reused for low-level signals.

Settings, measurement and timing of the RM35TM250MW

The measuring range is 208–480 V AC and 15–3100 Ω. Time delay: Without. Response time: > 50 ms (input Y1 (contact Y1-T1) and push-button). Reset time is listed as 10000 ms output.

When commissioning the RM35TM250MW, set the thresholds against the real running values of the plant, not against the nameplate alone. Where an adjustable fault delay is available, a longer time suits starting transients and short disturbances, while a short time protects equipment faster. Note the dial positions on the commissioning sheet so the settings can be restored after maintenance.

Information to send with an RFQ for the RM35TM250MW

• Exact reference RM35TM250MW and quantity.
• Supply voltage, frequency and type of network.
• The load or machine being supervised and the required alarm or trip behaviour.
• Required contact arrangement and rating.
• Related relays, sockets or accessories needed on the same order.
• Delivery location and timeline.

Documents and quotation

The Schneider Electric datasheet for the RM35TM250MW is attached on this page and holds the complete specification summarised above, as printed on the manufacturer’s document dated 7 Nov 2026.

Send us the reference RM35TM250MW, quantity and delivery location and Seven Star LLC will reply to your request. We supply as an independent supplier based in Muscat and do not act for the manufacturer.