Schneider Electric LADR0 TeSys D Off-Delay Timer Block 0.3-3 s

LADR0: short off-delay timer block with a 0.3 to 3 second range

The LADR0 is a Schneider Electric TeSys D time delay auxiliary contact block with an off-delay function and a delay range of 0.3 to 3 seconds. It adds a timed contact pair, one normally open and one normally closed, to the front of a contactor. Seven Star LLC supplies the LADR0 in Oman and the GCC as an independent supplier based in Muscat.

Off-delay means the contacts keep their position for the set time after the contactor coil is de-energised. With 0.3 to 3 seconds the LADR0 is the shortest-range block in this group, and it is meant for brief hold-over functions and not for long process delays.

Technical specifications of the LADR0

What the 0.3 to 3 second off delay of the LADR0 does

After the control signal drops and the contactor releases, the contacts of the block change state only after the set time. In a ventilation or lubrication circuit that is how a fan or an oil pump is kept running for a few seconds after the main drive has stopped, long enough for coasting or for a sealing flush.

The range is set on the block’s dial, and the datasheet gives 0.3 to 3 s. If you need 1 to 30 s, the sibling LADR2 has the same off-delay function with a longer range.

Mounting and ratings of the LADR0

The block fits on the front of TeSys D and TeSys Deca contactors and CAD relays, and on TeSys F LC1F and CR1F, which is the range compatibility line in the datasheet. It has one normally open and one normally closed time-delayed contact and measures 48 mm high, 44 mm wide and 61 mm deep. Rated operational voltage is 690 V AC at 25 to 400 Hz, thermal current is 10 A at 60 °C, rated current is 6 A at 120 V AC-15 and 1.04 A at 690 V AC-15, and the making capacity is 140 A AC. Mechanical durability is 5 Mcycles, the minimum switching level is 5 mA at 17 V, and the protection is IP20. The ambient air temperature range is -40 to 70 °C and the altitude limit is 3000 m.

LADR0 selection checklist

• Function: off delay, not on delay.
• Range: 0.3 to 3 s; check the required hold-over time fits.
• Contacts: 1 NO + 1 NC, time delayed.
• Contactor: TeSys D, Deca, F as listed.
• Space: the block is 61 mm deep, deeper than instantaneous blocks.

Timer block family: the LADR0 against its siblings

The five timer blocks below share the housing and contact ratings and differ in function and range.

Setting and testing the LADR0

Mount on the contactor, tighten terminals at 1.7 N.m, and set the dial. Use a stopwatch or a recording meter to confirm the delay at the setting, since the dial is a scale and not a precision instrument.

Because the delay begins when the coil drops, test with a real stop command and not by pulling the block.

LADR0 uses in Oman and the GCC

Short off-delay is a common requirement on fans, pumps and conveyors where a following device must run on briefly: lubrication pumps, cooling fans on drives, and purge or flushing valves.

In hot climates, cooling-fan run-on after the main motor stops is a frequent request for enclosures that heat soak.

Information to send with an RFQ for the LADR0

• Full reference and quantity required
• Contactor model the block mounts on
• Delay function (on or off) and time range needed
• Control voltage and load of the timed contacts
• Delivery location and timing

Documents and quotation

A datasheet for the LADR0 is attached on this page. It carries the electrical, mechanical and environmental data summarised above, so the figures can be checked against your drawings.

Send the part number, quantity and application and we will confirm availability and a quotation. Seven Star LLC is an independent supplier in Muscat and is not affiliated with the manufacturer.