WTA1 Power-on Delay Relay for Staged Start-Up in Control Panels
The WTA1 holds its output open for a set time after the supply appears, then closes the contact. That is the delay used to start a fan after a compressor, to hold a pump off until a level switch settles, or to sequence two contactors in one panel.
One Function, Two Knobs
The range knob picks the decade and the percentage knob trims inside it, which puts the whole span from 0.1 second to 10 days on an 18mm face. Setting accuracy is 10% and repeat accuracy 0.2%, so the tenth cycle closes as close as the first. A single function part leaves out the selector a multi range relay carries, which is one knob less for a panel builder to set wrong.
One Item for AC and DC Panels
A1 and A2 take AC or DC from 12 to 240V, so one stock line serves a 24V DC control panel and a 230V AC board. Power draw is 0.09 to 3VA on AC and 0.05 to 1.7W on DC. Supply tolerance is -15% to +10%, which covers a battery bank coming off charge.
Contact, Reset and Indication
The output is a changeover contact on 15, 16 and 18, rated 16A thermal current and 250V 5A under AC-15, which is enough for a contactor coil, a small pump starter or a lamp circuit. Minimum switching power is 500mW. Reset takes 200ms at most, so a short supply dip does not leave the delay half run. A green lamp shows the supply and a red lamp shows the output state.
Panel Fit
The body is 18mm wide and 90mm deep, one module on a 35mm rail, rated -20°C to +55°C at IP20. Terminals close on one 2.5mm² or two 1.5mm² conductors at 0.4N·m. Mechanical life is 10 million operations and electrical life 100,000 at resistive load. The same frame is offered with a delayed disconnection function and with two contact sets. Send your delay setting, supply voltage and quantity to WTAIELE for a quote.
