International Instruments Industries

The XT56A by Selec is a panel-mount thumbwheel (mechanical push‑wheel) timer used in industrial control panels. It supports ON‑Delay and Interval timing modes.

• Controlling delays in sequences in automation panels

• Interval timing: e.g. produce output for a fixed interval

• Industrial processes that need a simple timer: motor control, heating elements, conveyors, etc.

• Where a robust, visible timer is needed, and where reset from different sources might be useful

• Model: 642XA

• Type: Analog Timer (Time‑Delay Relay)

• Functions: On‑Delay / Interval modes (selectable)

• Mounting: DIN‑Rail mount (17.5 mm wide)

• Relay Contact Type: 1 C/O (SPDT)

• Contact Rating: 5 A @ 250 V AC or 24 V DC

• Size / Width: 17.5 mm DIN‑rail module width

• LED Indicators: Power ON, Relay ON

• Terminals: Finger‑safe terminals (meaning safer design for wiring access)

Good for situations where you need a timer that can either delay activation after power / input (on‑delay), or repeatedly run in “interval” mode (relay on for some time, off for some time) depending on wiring or control. Common in control panels, automation, process timing, starting motors, lighting, etc.

• Operating Mode: Forward → Pause → Reverse. That means the timer cycles through three phases: first a “forward” time, then a pause, then reverse.

• LED Indicators: There are LED indicators for Relay 1 (Forward) ON, and Relay 2 (Reverse) ON.

• ON Time (Forward / Reverse): Selectable among 1, 2, 4, or 8 minutes.

• Pause Time: Selectable among 10, 20, 40, or 80 seconds.

• Resolution:

  • ON Time: steps of 6 seconds.

  • Pause Time: steps of 0.1 second.

• Setting Accuracy: ± 5% of the full‐scale value.

• Repeat Accuracy: ± 0.5% or ± 50 milliseconds (whichever is relevant) for repeated cycles.

• Two separate relay contacts (each 1 C/O) for Forward & Reverse operations respectively. (“C/O” = Change‐over or SPDT)

• Contact Rating: 5 A at 250 V AC or 24 V DC.

• Supply Voltage Range: 20 to 240 V AC and 12 to 240 V DC. Universal supply.

• Width / Size: 22.5 mm (DIN profile width)

• Mounting Type: Designed for DIN‑Rail mounting.

• Useful in systems where a process needs to run “forward” for a time, then sit idle, then run “in reverse” (for unloading, back‑flushing, reversing motors, etc.).

• The selectable pause allows detection or rest between forward/reverse transitions.

• Because timing ranges are limited (max ON time 8 min, pause up to 80 s), it’s best suited for moderate time cycles, not very long delays.

• Model: XT546 (variants include XT546, XT546A, XT546BX, XT546‑24V etc.)

• Type: Dual‐display, multi‑function timer with single set‑point.

• Panel size / Cutout: 48 × 48 mm front panel.

• Display: Dual display (upper + lower), 3+3 digits, 7‑segment LED.

• LED indicators for: Relay ON status, hours/minutes/seconds mode etc.

• Rubber keys/front keypad for setting timers etc. “short depth” variants available.

• Time Ranges: 9 selectable ranges, covering seconds, minutes, hours. Examples include:
  • 9.99 / 99.9 / 999 seconds,
  • 9:59 minutes:seconds,
  • 99.9 / 999 minutes,
  • 9:59 hours:minutes,
  • 99.9 / 999 hours.

• Operating Modes:
  • ON‑Delay
  • Interval
  • Cyclic ON first
  • Cyclic OFF first

• Counting Direction: Selectable (Up or Down). Some listings show “Down selectable” or “Up/Down” depending on variant.

• Start / Reset Inputs:
  • Reset from front panel, remote reset, or upon power interruption.
  • Start input can be “Pulse / Gate” in some variants.

• Memory Retention: Yes — retains settings/time through power interruptions in many variants.

• Relay Outputs: 1 C/O SPDT (some variants have 2 C/O SPDT) depending on version

• Contact Rating: ~5 A at ~250 VAC (common in SPDT relays in this family)

• Supply Voltage: Universal / wide range. Many variants: 85‑270 V AC/DC. Some have 24 V AC/DC option.

• Operating Temperature: Around 0 to +50 °C in many listings.

• Storage Temperature: −20 to +75 °C in some variants

• Humidity: Up to ~95% RH, non‑condensing.

• Weight: Approx ~140 g in some listings.

• Accuracy: ±0.05 % of set time or ±50 ms (whichever is greater) in many variants.

• Resolution / Minimum Setting Time: As low as 0.01 seconds in many variants.

• Power variant: XT546-24V (24 V AC/DC supply)

• Short depth version: XT546BX variant which is “short depth” design.

• Some carry 2 relay outputs (2 C/O) in certain versions.

ON Delay Interval Timer with 7 Time Ranges (48x48 mm) provides adjustable delay intervals with seven selectable time ranges for precise control. Its compact design makes it ideal for space-constrained industrial applications requiring reliable timing functionality.

• Display: 3-digit, 7-segment LED, single red display.

• Time ranges (7 selectable):

  • 9.99 / 99.9 / 999 seconds

  • 99.9 / 999 minutes

  • 99.9 / 999 hours

• Operating modes: ON-Delay and Interval.

• Counting direction: Down (i.e., countdown)

• Time setting: By thumb-wheel (push-wheel) switches.

• Reset mechanisms: Front (panel) reset, remote reset input, and reset by power interruption.

• Supply voltage: 90 to 270 V AC / DC.

• Mounting / Size: Panel mount, 48 × 48 mm cut-out.

• Outputs: 2 C/O (SPDT) relay contacts.

• Weight & dimensions: From one supplier: net weight ≈ 120 g; Gross ≈ 170 g; Size 48×48 mm.

• The “thumb-wheel” setting makes it quick to set the desired time without needing programming or software.

• With dual C/O relays, you can use the timer to switch two independent circuits (e.g., one NO, one NC) or use for more flexible control logic.

• Because the supply range is wide (90-270 V AC/DC), it is well suited for industrial panels where supply may vary, or when you want a universal input.

• The countdown mode means when power is applied (or when the relevant start input is triggered) the timer counts down from the set value, and at the end the relay operates (depending on ON Delay vs Interval).

  • ON-Delay mode: on applying power, after the delay the relay energises.

  • Interval mode: on applying power, relay energises immediately then de-energises after the set time. (Typical interpretation)

• Environment: One datasheet for a similar model (XT543) lists operating temperature 0-50 °C, humidity up to 95% RH non-condensing.

• Pricing and availability: At least one Indian supplier lists it around ₹ 921 (incl GST) for this model.

• Contact (relay) current rating: I did not find a direct spec for the DXT53 model in the sources accessed. However, other models in the same series (and from same manufacturer) list 5 A at 230 V AC for outputs. So you should verify the exact rating (AC/DC, resistive vs inductive load) from the official datasheet or manufacturer for DXT53.

• Accuracy / Repeatability: The similar timer series list ±0.5% of set time or 50 ms whichever is greater. (e.g., in XT543A spec) It is likely DXT53 has a similar accuracy but you should confirm.

• Start input details: Whether there is a “gate/pulse” start or purely on supply apply may vary. The listing for DXT53 mentions “Time Setting: By push wheel switches” but does not clearly mention start input type.

• Depth / panel cut-out / mechanical details: The front size is 48×48 mm, but depth/back clearance may vary – check datasheet for your panel’s depth constraints.

Thumbwheel Timer with On Delay Interval Function (96 x 96 mm) offers precise time delay control with a user-friendly thumbwheel interface. It is designed for reliable time-based operations in industrial and automation applications, providing accurate delays and intervals.

Thumbwheel Timer with On Delay Interval Function (72 x 72 mm) provides precise time delay control with an easy-to-use thumbwheel for setting intervals. It is ideal for industrial applications requiring accurate timing and delay sequences in a compact design.

• Accuracy: ±0.05% of full‑scale or ±50 ms, whichever is greater.

• Certification: CE certified

On Delay Interval Timer with 8 Time Ranges is designed to delay the activation of a connected load after a preset time interval. It offers 8 adjustable time ranges, allowing flexibility for different delay durations depending on the application. The timer is commonly used in automation and control systems where a precise delay is needed before the start of an action, such as in motors or lighting. Its reliable performance ensures accurate time control, preventing premature operations. The versatility of the 8 time ranges makes it suitable for various industrial and commercial uses.

The Selec 642SQ‑A is a versatile analog timer offering two operating modes—On‑Delay and Interval—with selectable timing ranges. Here’s a detailed breakdown:

• Modes: On-Delay and Interval timing options.

• Time Ranges: Four selectable ranges—0–3 sec/min, 0–10 sec/min, 0–30 sec/min, and 0–60 sec/min. Resolution is 0.3 seconds.

• Resolution: 0.3 seconds.

• Accuracy: Setting accuracy ±5% of full scale; repeat accuracy ±0.5% of full scale.

• Output: Single SPDT relay (1 C/O).

• Contact Rating: 5 A at 250 VAC or 24 V DC.

• Supply Voltage: Dual—supports both 230 V AC and 24 V AC/DC.

• LED Indicators: Displays both Power ON and Relay ON status.

• Terminals: Designed with finger-safe protection.

• Size: Slim 17.5 mm width, DIN‑rail mountable.

• Mounting: Easily clips onto DIN rails, ideal for compact panel installations.

On Delay Timer with 10 Time Ranges is designed to delay the activation of a connected load for a set period after receiving a trigger signal. It offers 10 adjustable time ranges, allowing precise control over the delay duration to suit different applications. This timer is ideal for processes that require a specific delay before starting an action, such as in motor control or lighting systems. The versatility of the 10 time ranges ensures it can accommodate a wide variety of timing needs. It provides reliable and accurate performance in both industrial and commercial settings.

On Delay Interval Timer with 8 Time Ranges is designed to provide a time delay before activating a connected load. It features 8 adjustable time ranges, allowing users to set the delay duration according to specific needs. This timer is ideal for controlling processes that require a precise delay before starting, such as motor or lighting systems. Its reliable performance ensures consistent operation in various automation applications. The versatility of the time ranges makes it suitable for a wide range of industrial and commercial uses.

On Delay Timer with Single Time Range is a simple device designed to delay the activation of a connected load by a fixed time interval. It offers a single, predefined time range, providing easy and straightforward control for applications requiring a consistent delay. The timer is commonly used in processes where a delay is needed before initiating actions, such as starting motors or lighting systems. Its reliable performance ensures accurate timing without the complexity of multiple adjustable settings. This timer is ideal for basic automation tasks in industrial or commercial applications.

Dual Display 9 Time Ranges Multifunction Timer (72 x 72 mm) offers dual display for simultaneous time tracking across nine selectable time ranges. Its short depth design ensures easy installation in space-restricted industrial environments while providing versatile timing functions.