Schneider Electric RE17RMMW — Multifunction Relay Buyer Review

By Abdullah Zahid
14 min read
Schneider Electric RE17RMMW multifunction DIN rail timer relay 8A 12-240V for industrial panel automation

Schneider Electric RE17RMMW Multifunction Relay, Harmony Timer Relays, 8A, 1CO, 0.1s–100h, Power On Delay, 12–240V AC/DC: Complete Specs, Pricing and Selection Guide

If you are a controls engineer or procurement specialist narrowing down a multifunction timing relay for a machine automation, HVAC, or fluid control application, the Schneider Electric RE17RMMW sits at the intersection of maximum flexibility and minimum panel footprint. This solid-state modular relay handles the full span from 0.1 seconds to 100 hours, accepts 12–240V AC or DC from the same unit, and switches 8A at 250 VAC — all from a 17.5mm-wide DIN rail module with no external programming tools required. The question is not whether it performs; the question is whether the 8A contact limit, 1CO output form, and selector-switch adjustment method match your exact application before you place the order.

If you have already confirmed this is the right part, check current pricing and availability for the RE17RMMW at LeadTime.ca — ships worldwide.

Who Should Buy the RE17RMMW — and Who Shouldn't

The RE17RMMW is right for engineers and technicians who need a single DIN rail timer that can be configured on-site for multiple delay modes without swapping modules or reprogramming a controller. This is an ideal choice when all of the following are true:

  • Your load amperage does not exceed 8A continuous at 250 VAC, including inrush for inductive loads
  • Your application delay falls between 0.1 seconds and 100 hours, with ±0.5% repeat accuracy being sufficient
  • Your control cabinet runs anywhere from 12V DC to 240V AC — the RE17RMMW accepts both on the same part
  • DIN rail mounting on a standard 35mm rail is your panel standard, and 17.5mm module width fits your available space
  • Front selector-switch commissioning is acceptable — no remote or networked timing setpoint is required
  • A 1CO (one changeover, Form C) contact output is sufficient for your switching logic

If your load exceeds 8A, consider the RE17RTMM (16A variant). If you need a remote potentiometer setpoint, the RE17RDMM is the correct specification. If your application requires a 4–20mA input for networked timing control, specify the RE17RPMM instead.

On this page:

What the RE17RMMW Actually Does in a Control Circuit

The RE17RMMW is a solid-state multifunction time delay relay from Schneider Electric's Harmony Timer Relay family, also referenced as part of the Zelio Modular Timing Relay line. Its core role is straightforward: it sits between a triggering input — a sensor output, pushbutton, or logic signal — and a downstream actuator or load, inserting a programmable delay between the two. Where a standard relay closes instantly, the RE17RMMW holds off that closure (or opening) for a precisely set duration ranging from 0.1 seconds to 100 hours.

What separates this unit from a single-function timer is its multifunction capability. One RE17RMMW can be configured for power-on delay, on-delay, off-delay, pulse output, or power-off delay simply by selecting the appropriate mode via the front rotary selector switch — no rewiring, no module swap, no software tool. Seven selectable timing ranges are built into that same switch, covering approximately one decade of values each. This means a single stocked spare covers applications from a 0.5-second solenoid debounce delay all the way to a 24-hour overnight cycle timer.

The diagnostic button on the front panel allows a technician to manually fire the output impulse without cycling the panel power. With a response time under 100ms typical, this makes field verification of downstream wiring a quick, practical step during commissioning rather than a full-panel restart event. Contacts are cadmium-free and the unit carries CE, CSA, and cULus certification, making it acceptable for cross-border projects in North America and Europe alike.

Typical System Architecture and Signal Chain

The RE17RMMW occupies the timing control layer between the signal source and the final actuator load. Understanding where it sits in the chain helps verify wiring logic before installation.

  • Control power supply (12–240V AC or DC) feeds terminals A1 and A2 on the relay, providing operating power to the timing circuit
  • A digital trigger input — typically a pushbutton, proximity sensor NPN/PNP output, or PLC digital output — connects to the timing input terminals to start or gate the delay sequence
  • The RE17RMMW's 1CO (Form C) output contact switches the downstream load circuit; this contact can directly drive loads up to 8A at 250 VAC or be wired to a contactor coil that drives heavier loads
  • For inductive loads such as solenoid valves or motor starter coils, a flyback diode or snubber is placed across the load to protect the 1CO contact from inductive kick on de-energization
  • The front selector switch sets timing range and delay value; the diagnostic button on the front panel allows output test without disturbing the main power circuit

Where the RE17RMMW Gets Specified: Applications and Industries

In machine automation environments, the RE17RMMW is commonly specified for conveyor start-delay sequences — holding motor energization for a set period after an emergency stop is released, giving safety guards time to fully close before the drive restarts. The 0.1-second to 100-hour range accommodates everything from a 2-second guard verification delay to multi-hour lockout hold-off sequences in a single module.

Hydraulic and pneumatic system designers use the RE17RMMW in power-off delay configurations to prevent rapid pressure drop on shutdown. A 5-second drain period after the main pump signal drops protects actuators from pressure shock. Similarly, solenoid valve coil protection against electrical noise is a textbook application: a 0.5-second energization delay after the triggering signal filters out switch bounce and relay chatter that would otherwise cause false coil actuation.

HVAC system integrators specify the RE17RMMW for fan-on delay after compressor start — a 10-second hold allows refrigerant pressure to stabilize before airflow begins. Pump control panels use the off-delay mode to add a 30-second run-on after a tank level signal drops, preventing cavitation from dry-running a centrifugal pump. Water treatment dosing systems benefit from the pulse output mode for intermittent pump actuation timed to a process cycle.

Application Typical Deployment
Conveyor start sequencing On-delay after e-stop release; 2–5 second guard closure verification window
Hydraulic pump shutdown Power-off delay; 5-second drain period before full de-energization
HVAC compressor-fan sequencing On-delay post-compressor start; 10-second pressure stabilization hold
Solenoid valve noise suppression On-delay 0.5 seconds after trigger signal to filter contact bounce and EMI
Water treatment pump protection Off-delay 30 seconds after tank level drop signal to prevent cavitation
Dosing pump intermittent control Pulse output mode for timed dosing cycles without PLC involvement

Key Electrical, Timing, and Physical Specifications

Parameter RE17RMMW Value Notes
Contact Rating 8A at 250 VAC Thermal derating applies above 40°C ambient; consult datasheet derating curve
Contact Form 1CO (Form C) One changeover; breaking capacity 2000 VA
Supply Voltage 12–240V AC/DC Same part accepts AC or DC; 50/60 Hz ±5%
Power Consumption ≤3 VA at 240 VAC; ≤1.5W at 240 VDC Negligible load on control power supply
Timing Range 0.1 seconds to 100 hours Seven selectable ranges via front rotary selector
Repeat Accuracy ±0.5% Per IEC 61812-1; suitable for non-precision sequencing
Temperature Drift ±0.05% per °C Stable across -20°C to 60°C operating range
Operating Temperature -4°F to 140°F (-20°C to 60°C) Suitable for unheated cabinets and climate-controlled buildings
Mounting / Width 35mm DIN rail / 17.5mm wide Standard symmetrical DIN rail; clips in and out for serviceability
Certifications CE, CSA, cULus Listed Cadmium-free contacts; RoHS compliant; acceptable for cross-border projects

Full technical specifications are available on the product page at LeadTime.ca.

RE17RMMW vs. RE17RTMM, RE17RDMM, and RE17RPMM: Which Variant Do You Need?

Variant Part Number Contact Rating Setpoint Method Best For
Standard Relay Output RE17RMMW 8A Front selector switch On-site commissioning; most common panel application
Higher Amperage RE17RTMM 16A Front selector switch Loads exceeding 8A; upgrade path without changing form factor
Potentiometer Input RE17RDMM 8A Front potentiometer Continuous 0–100% range adjustment; no stepped ranges
Programmable Input RE17RPMM 8A 4–20 mA remote input Networked timing setpoint; no field visit required to adjust
Solid-State Output RE17RSMM 8A Front selector switch High-cycle applications; no contact bounce; lower contact resistance

If your load exceeds 8A or inrush current pushes the relay beyond its continuous rating, the RE17RTMM is the correct upgrade — same DIN rail mounting, doubled contact capacity. Check current availability for all RE17R family variants at LeadTime.ca.

Expert Verdict: Is the RE17RMMW Worth Specifying?

The RE17RMMW earns its place in OEM panel builds and retrofit automation projects because it solves a real inventory and commissioning problem: instead of stocking five fixed-delay timers covering different ranges, one RE17RMMW covers 0.1 seconds through 100 hours across seven selectable ranges, and can be reconfigured for on-delay, off-delay, pulse, or power-off delay without any tools or software. For plant engineers and control integrators in small to mid-size facilities — HVAC, machine automation, water treatment — where a trained technician will commission and occasionally adjust the relay on-site, this is the correct level of sophistication. The 17.5mm DIN rail footprint, wide 12–240V AC/DC supply acceptance, and cULus/CSA/CE certification make it a genuinely universal panel component across mixed-voltage, cross-border projects.

Where the RE17RMMW has real limits: the 8A contact rating is non-negotiable, and inductive inrush on solenoid or motor coil loads must be calculated before ordering — not estimated. If combined steady-state and inrush load exceeds 8A, the RE17RTMM (16A) is the correct specification. If your application requires timing setpoints to be changed remotely or via a supervisory system without physical access to the panel, the RE17RPMM with 4–20mA input is the right choice. For millisecond-precision timing, a PLC timer function or a dedicated high-speed relay is more appropriate than any selector-switch-adjusted module. The 1CO (Form C) output is sufficient for most sequencing logic, but applications requiring two simultaneous independent switching circuits need a different contact configuration.

From a procurement standpoint, the RE17RMMW carries no significant sourcing risk — Schneider Electric confirms normally stocked status through authorized North American distributors, and the part has a verified presence across multiple distribution channels worldwide. That said, lead time confirmation before committing to a project schedule is always worth the 10-minute step, particularly for urgent builds or multi-unit orders. Buying through a specialist industrial automation distributor rather than a generic channel gives you accurate real-time stock confirmation, technical pre-sales support to verify contact form and output type match, and compatible accessories — DIN rail hardware, terminal blocks, filter modules — available in a single order. View current pricing and lead time for the RE17RMMW at LeadTime.ca, with worldwide shipping available.

For volume pricing or to confirm lead time before committing to a build, contact the LeadTime.ca team directly — we ship worldwide.

What Engineers Need to Know Before Ordering the RE17RMMW

Because community discussion specific to the RE17RMMW is sparse across the major automation forums, the most useful pre-order intelligence comes from the technical constraints and ordering mistakes that consistently surface when engineers specify modular timing relays in this category. The issues below represent the gap between what looks straightforward on a spec sheet and what causes rework, warranty headaches, or project delays when the part arrives on site.

The single most common specifying error in the RE17R family is underestimating load amperage. The 8A contact rating is a continuous rating at rated ambient temperature — it is not a peak or inrush rating. Inductive loads such as solenoid coils and motor starter coils draw 3 to 5 times their steady-state current on first energization. An engineer who measures a solenoid valve coil at 2A steady-state and assumes it is well within the 8A limit may be operating at 8–10A inrush on every cycle, accelerating contact wear to the point of failure within months. The fix is to calculate cold-start inrush before ordering and, where inrush is uncertain, plan to use the RE17RMMW output to drive a separate contactor coil rated for the actual load rather than switching the load directly.

The second area where engineers encounter friction is the contact form assumption. The RE17RMMW provides one changeover (1CO) contact — one normally open and one normally closed pair sharing a common terminal. Applications that require two independent switching circuits in the same timing event need a different specification, either a model with 2CO contacts or an additional relay in the circuit. Ordering the RE17RMMW for a 2CO application and discovering the mismatch at panel assembly is an avoidable delay. The third area worth flagging before order is the selector switch adjustment method: it is entirely front-panel and manual, with no remote input capability. This is an asset for on-site commissioning — no tools, no power cycle — but it is a constraint for any application where timing setpoints need to change without physical panel access. Confirming this constraint matches the maintenance model for your facility before ordering prevents a specification change after the part is in the cabinet.

Wiring and Installation Overview

The following covers the key installation requirements for the RE17RMMW. For complete wiring diagrams and terminal assignments, consult the official Schneider Electric installation manual and datasheet for this model.

  • Mount on a standard 35mm symmetrical DIN rail; the 17.5mm module width requires deliberate space planning on crowded panels — confirm adjacent module clearance before layout is finalized
  • Connect control supply (12–240V AC or DC) to terminals A1 and A2; verify polarity if using DC supply, and confirm that the supply voltage is within the 12–240V range before energizing
  • Wire the triggering input signal (sensor output, pushbutton, or PLC digital output) to the designated timing input terminals per the datasheet terminal diagram; use shielded cable for input runs routed near high-voltage or switching circuits
  • Connect the load to the 1CO output terminals (normally open or normally closed pair as required by your switching logic); do not exceed 8A continuous at 250 VAC — for inductive loads, add a flyback diode or snubber across the load terminals to protect contacts from back-EMF
  • After wiring, use the front-panel diagnostic button to verify downstream circuit operation before full commissioning — the output will energize for the diagnostic pulse duration without requiring a full power cycle

Wrong-Part Prevention Checklist

Before submitting your order for the RE17RMMW, work through each item on this checklist to confirm the part is correct for your application. These checks are drawn directly from the most common specification errors in the RE17R family.

  1. Verify load amperage does not exceed 8A continuous; thermal derating may apply — confirm via distributor derating curve
  2. Check application voltage is 12–240V AC or VDC; confirm polarity if DC (positive or negative ground)
  3. Confirm timing range: Is 0.1 second minimum and 100 hour maximum sufficient, or is millisecond resolution needed?
  4. Verify contact form 1CO (one changeover) is correct; do not confuse with 2CO or 4CO models
  5. Ensure DIN rail mounting space is available; unit is 0.69 inches (17.5mm) wide — account for adjacent modules
  6. Confirm selector switch front adjustment method is acceptable for commissioning (not remote potentiometer setpoint)
  7. Check if solid-state or relay output is needed; both options exist within RE17R family — specify at order
  8. Verify country of origin (Indonesia per source) and compliance (CE, CSA, cULus) matches project requirements

If any item on this checklist raises a question before you order, contact the LeadTime.ca team for technical pre-sales support — or view the full product details on the RE17RMMW product page to confirm specifications before committing.

Frequently Asked Questions

Can I adjust the timing delay on the RE17RMMW without shutting down the panel?

Yes. The front rotary selector switch can be adjusted while the unit is powered — no power cycle is required and no software tools are needed. Changes take effect immediately. However, confirm with your facility maintenance procedure whether live adjustment is safe for your specific application; in processes where an unintended timing change could affect product quality or safety, restricting front-panel access or adding a shutdown requirement to your maintenance procedure is advisable.

What happens if my load draws more than 8A — will the relay trip or will contacts fail silently?

The RE17RMMW does not have an internal overcurrent trip. If continuous load current or inrush exceeds the 8A contact rating, contact arcing and accelerated wear occur without an immediate failure indication. Contacts may appear to function for some time before contact resistance increases and switching reliability degrades. For loads where inrush is uncertain, calculate cold-start current (3–5x steady-state for inductive loads) and either specify the RE17RTMM (16A) or use the RE17RMMW to switch a larger external contactor rated for the actual load.

What is the difference between on-delay and power-on delay on the RE17RMMW?

On-delay starts the timing sequence when the input trigger signal is applied and closes the output contact after the set delay elapses; the timer resets when the input signal is removed. Power-on delay starts the timing sequence when supply voltage is applied to the relay itself, regardless of the input signal state — it provides a global startup delay for the circuit independent of any external trigger. Selecting the correct mode for your application logic is a commissioning step done via the front selector switch.

Is the RE17RMMW suitable for direct replacement of older fixed-delay timer relays in a retrofit?

In most cases yes, provided the replacement application falls within the 8A contact rating, 1CO contact form, and 12–240V supply voltage range. The seven selectable timing ranges mean the RE17RMMW can replicate the delay value of most fixed-timer applications without a special-order part. Verify terminal assignments against the original unit's wiring diagram before installation, as terminal numbering conventions vary between manufacturers and product generations.

What do the LED indicators on the RE17RMMW indicate during operation?

The indicator LED confirms relay operating status — lit when the output contact is energized, unlit when the output is open. During timing, the LED state reflects the current output condition based on the selected timing mode. The front-panel diagnostic button allows a technician to manually pulse the output and verify LED response and downstream circuit continuity without cycling the panel power. Consult the official Schneider Electric datasheet for exact LED behavior in each timing mode configuration.

What certifications does the RE17RMMW carry, and is it acceptable for Canadian projects?

The RE17RMMW carries CE, CSA, and cULus listings, confirming compliance with European, Canadian, and US safety standards. CSA and cULus certification specifically covers Canadian and US market requirements, making it acceptable for projects subject to Canadian Electrical Code inspection without additional approval steps. The unit also features cadmium-free contacts and is RoHS compliant, simplifying end-of-life documentation for projects with environmental compliance requirements.

Why Order the RE17RMMW Through LeadTime.ca

  • Worldwide shipping — the RE17RMMW ships from LeadTime.ca to industrial buyers globally, not limited to any single region
  • Real-time stock confirmation before you commit to a project schedule — no surprises at order placement
  • Technical pre-sales support to verify contact form, output type, and timing range match your application before the part ships
  • Compatible accessories — DIN rail hardware, terminal blocks, and filter modules available in the same order
  • Volume pricing available for OEM builds and multi-unit panel orders — contact for current pricing on quantities

RE17RMMW At-a-Glance Summary

  • Contact rating: 8A at 250 VAC, 1CO (Form C), 2000 VA breaking capacity
  • Supply voltage: 12–240V AC or DC — same part number, no separate SKU by voltage
  • Timing range: 0.1 seconds to 100 hours across seven selectable front-panel ranges
  • Repeat accuracy: ±0.5% per IEC 61812-1; temperature drift ±0.05% per °C
  • Power consumption: ≤3 VA at 240 VAC; ≤1.5W at 240 VDC
  • Mounting: 35mm DIN rail; 17.5mm (0.69 inches) wide module
  • Operating temperature: -4°F to 140°F (-20°C to 60°C)
  • Diagnostic button: output test under 100ms typical response without power cycle
  • Certifications: CE, CSA, cULus Listed; RoHS compliant; cadmium-free contacts
  • Upgrade path: RE17RTMM (16A) for higher load; RE17RDMM for potentiometer setpoint; RE17RPMM for 4–20mA remote input

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