What is the Schneider Electric Zelio Time range, and how do RE17 and RE22 differ? Zelio Time is Schneider's line of 17.5 mm and 22.5 mm DIN-rail electronic timing relays, built to IEC 61812 and IEC 60947-5-1, spanning on-delay, off-delay and multifunction/multi-range operation. RE17 is the single-function, fixed-configuration compact series; RE22 packs several functions and timing ranges into one modular housing selected by a rotary switch, and RE22R adds a second output for star-delta sequencing. This review covers function coverage, timing ranges and repeat accuracy, contact ratings, supply options, and the REXL plug-in variant, set against the wider stock of timing and control relays Stoklink carries.
RE17: Single-Function Compact Timers
RE17 devices ship as fixed-function units — an RE17 on-delay part times only on-delay, an RE17 off-delay part times only off-delay. There is no rotary function select. That is the trade-off: less flexibility per part number, but a simpler front panel and one fewer failure mode, since a technician cannot mis-set the function dial on a job that was specified as on-delay from the start. The 17.5 mm width lets a panel builder fit more timers per DIN rail run than a 22.5 mm multifunction unit, which matters on tight door panels.
Multi-voltage supply options, typically spanning a wide AC/DC band on the broader parts, mean one catalog number often covers several control-voltage classes, cutting the number of variants a distributor stocks. Output is a change-over (SPDT) contact rated for a few amps — adequate for driving a contactor coil or a PLC digital input, not for switching motor current directly.
RE22: Multifunction, Multi-Range Timers
RE22 puts several functions — on-delay, off-delay, star-delta, flasher, single-shot — behind one rotary function switch, plus a separate rotary range switch that steps the timing base from fractions of a second up through hours. One stocked part number then covers what would otherwise be four or five RE17 fixed-function parts. The saving shows up in spares inventory more than in per-unit price: a panel shop standardizing on RE22 across a product line holds one SKU instead of five.
RE22R variants add a second change-over output specifically for star-delta timing relay sequencing — one contact drives the star contactor, the other drives delta, with the transition dead-time set on the same dial block. See how to wire a contactor for star-delta motor starting for the contactor-side wiring this pairs with.
REXL and Plug-In Formats
REXL is the plug-in (socket-mounted) branch of Zelio Time, sold in 8-pin and 11-pin footprints. Socket mounting lets maintenance swap a failed timer without disturbing field wiring — pull the relay, plug in a spare, done. That convenience costs panel depth, since the socket adds height behind the DIN rail, and it adds a second failure point at the socket contacts. Most new panel designs favor the DIN-rail RE17/RE22 body unless the plant already standardizes on socketed relays across its panel fleet for spares commonality.
Timing Ranges and Repeat Accuracy
RE17 fixed-function parts typically cover one or two timing ranges per catalog number. RE22 multi-range parts step from a fraction of a second up to 100 hours across multiple rotary positions, so one part serves a machine-start delay and a batch-process delay equally. Repeat accuracy — how much a re-triggered timer's actual output time drifts from the previous cycle at the same dial setting — is the number to check against the process, not the absolute setting accuracy.
Formula: Repeat accuracy error — Source: IEC 61812, timing relay characteristics
terror = tset × (repeat accuracy % / 100)
| Symbol | Description | Unit |
|---|---|---|
| tset | Timer setting (dial value) | s, min, or h |
| repeat accuracy % | Manufacturer-stated repeat accuracy, typically ±0.5% to ±1% of set value | % |
| terror | Worst-case cycle-to-cycle drift at that setting | same unit as tset |
At a 30 s star-delta transition setting, a ±1% repeat accuracy timer drifts about ±0.3 s cycle to cycle — irrelevant for a 30 s run-up delay, but worth checking on a process step timed in single-digit seconds, where a 1% drift is a larger fraction of the interval. What we see in the field: most nuisance "timer not repeating" complaints trace back to a loose supply connection or a marginal trigger pulse, not the stated accuracy spec.
Contact Ratings, Supply Voltage and Mounting
Both RE17 and RE22 output change-over contacts — 1 c/o, or 2 c/o on the star-delta variants — rated in the low-amp range at 250 V AC, enough for a contactor coil or an interposing relay coil, not enough for direct motor switching. Multi-voltage models on both series accept a wide AC/DC control-voltage band, cutting the catalog numbers a distributor needs across 24 V DC control panels and 110/230 V AC control panels.
Mounting is 35 mm DIN rail, or the REXL socket, with screw or spring terminals depending on the specific reference. Front-panel dial and LED status indication are standard across the range. A lit LED signals output contact state, not timing-in-progress on every reference — check the specific part's indication logic before reading "LED on" as "timer running."
RE17 vs RE22: Which One to Specify
The decision comes down to how many distinct timing functions a project needs, weighed against how much stocked-part variety the buyer wants to manage. Field observation: contractors building for a single repeatable machine design standardize on RE17 fixed parts and never touch a function dial again after commissioning. Contractors building varied one-off panels for different clients standardize on RE22, so the same box of spares covers on-delay, off-delay and star-delta jobs.
| Criteria | RE17 | RE22 / RE22R | REXL (plug-in) |
|---|---|---|---|
| Function selection | Fixed at manufacture, no dial | Rotary function + range dial, multifunction | Fixed or multifunction depending on reference |
| Width / mounting | 17.5 mm DIN rail | 22.5 mm DIN rail | 8-pin / 11-pin socket |
| Star-delta output | Not applicable | RE22R: two c/o outputs | Depends on reference |
| Best fit | Fixed-design machines, tight panel width | Varied projects, spares consolidation | Sites standardized on socketed relays |
Where Zelio Time Fits Against Other Control Relays
A Zelio Time timer only delays a switching event; it does not measure voltage, current, phase sequence or insulation, which is the job of a monitoring relay. Nor does it isolate or step down a control signal between circuits — that is an interface/coupling relay's job. On a star-delta starter, the RE22R drives the sequence timing while contactors do the actual switching; on soft-start applications, a soft starter replaces the star-delta contactor set entirely. For background on function selection across brands, see the timing relay engineering guide, and for the single-function-vs-multifunction trade-off in general, see multifunction and multi-range timing relays explained.
Selecting between RE17 and RE22 on a specific job follows the same checklist regardless of brand. See how to select a timing relay for your application for the function, range, accuracy and contact-rating checklist applied step by step.
Frequently Asked Questions
What is the difference between Zelio Time RE17 and RE22?
RE17 is a fixed single-function 17.5 mm timer with no function dial. RE22 is a 22.5 mm multifunction, multi-range timer selected by rotary switches, covering several timing functions and ranges in one part number, and RE22R adds a second output for star-delta sequencing.
Can RE17 or RE22 switch a motor directly?
No. Both output a low-amp change-over contact rated for a contactor coil or PLC input, not for direct motor current. Use the timer output to drive a contactor or interposing relay that then switches the motor.
What does repeat accuracy mean on a Zelio Time timer?
Repeat accuracy is the maximum drift in actual timed output between successive cycles at the same dial setting, typically stated as a percentage of the set value. It is separate from setting accuracy, which covers how closely the dial position matches the labeled time.
Is REXL better than RE17 or RE22?
Not universally. REXL trades panel depth and an extra socket contact point for tool-free field replacement. Choose it when a site standardizes on plug-in relays for spares handling; otherwise the DIN-rail RE17/RE22 body is the more compact, lower-part-count option.
Does RE22R replace a dedicated star-delta timer relay?
Yes. RE22R is Schneider's dedicated two-output star-delta function within the Zelio Time range, timing both the motor run-up and the star-to-delta transition dead-time from the same device.
What standards do Zelio Time timing relays meet?
Zelio Time relays are built to IEC 61812 (time-delay relays for industrial use) and IEC 60947-5-1 (control-circuit devices and switching elements), the same baseline standards that apply across other manufacturers' industrial timing relays.
Conclusion
RE17 and RE22 cover the same functional ground as most competing DIN-rail timer families: on-delay, off-delay, star-delta and multifunction, packaged as fixed-function compact parts on RE17 or rotary-configurable multifunction parts on RE22/RE22R, with REXL covering the plug-in-format need. The practical selection question is not which series is "better," but how many distinct timing functions a project and its spares strategy actually need managed across how many stocked part numbers.