Panasonic LT4H Digital Timer ATL5117: Comprehensive Guide for Industrial Automation Applications

What this delivery is: a Matsushita (NAiS) LT4H digital timer — the Japan-built AC240V variant, with the stock code ATL5117 printed on the label beside the model number. It arrived second-hand in excellent shape on 2026-01-30, 0.5 kg, with a three-month warranty, and it carries one of the clearer identity labels we have handled: model, variant, input range, contact rating, wiring logic and approvals all on one sticker, photographed below. One housekeeping note from the record before the details: this particular unit was subsequently returned to the supplier and refunded, so the photos stand as the delivery record of a unit that is no longer in stock.

What the label says

The NAiS brand and the Matsushita Electric Works maker line date the unit to before the full Panasonic rebrand — same company, the control-components era. The identity block reads: LT4H DIGITAL TIMER, the variant suffix LT4H-AC240V, and the seller's stock number ATL5117 beside it. The ratings block: input voltage 100-240V~ at 50/60 Hz — note the universal input even on the AC240V-suffixed model — and a contact rating of 5A 250V~, pilot duty C300. The logic block draws the four control inputs (RESET, START, STOP, LOCK) and the 11-pin circular pinout with the timed NC and NO contacts sketched in. Approvals: cRUus and CE. Maker block: Matsushita Electric Works Ltd., Made in Japan, code 000626-P.

How the LT4H works on a panel

The LT4H is a 48 by 48 millimetre DIN-panel multifunction timer, the classic form factor that snaps into a standard square cutout. The front carries an LCD readout and four blue push keys — the photo shows the UP/DOWN key rows — plus a yellow indicator window for the output state. Configuration is done without any software: an eight-way DIP bank inside selects the operation mode (signal-on delay, signal-off delay, interval, flicker and the rest of the A-through-G family), and a second bank sets the time range, from a 9.999-second scale all the way out to 999.9 hours, so the same physical unit covers from fractions of a second to weeks of accumulated time. Four logic inputs — reset, start, stop, lock — let the machine's own wiring control the countdown rather than the operator.

It plugs into a separate 11-pin circular socket, which is why the rear of the unit in our photos is a keyed round pin field: you wire the socket once on the panel door or the cabinet plate, and the timer itself swaps out in seconds when it fails. That plug-in arrangement is the reason these timers are still pulled from service panels twenty-five years after the 000626 date code on this unit's label.

The twin delivery in the same order

For completeness: the sourcing record shows a second LT4H in the same purchase from the same supplier — a 100-240V unit built in China, received 2026-01-28, also second-hand at 90 percent with a three-month warranty. The unit photographed on this page is the Japan-built AC240V-suffixed one, received two days later on 2026-01-30; per the record it was returned to the supplier and the payment refunded, which is why only this photo record remains of it. The functional difference between the two variants is nil on paper — the label itself declares the same 100-240V universal input — but the two entries exist because they were two separate physical units with two different factories behind them.

Photos and video

Video: inspection clip of the LT4H before dispatch.