WTT8-S1 Asymmetric Cycler Timer Relay for Unequal ON and OFF Times
The WTT8-S1 switches its output on and off in a repeating cycle, and the two halves of that cycle are set independently. A ventilation damper that needs four minutes open and twenty minutes closed, or a lubrication pump that runs for seconds between long rests, fits this relay without a second timer.
Two Times, Four Dials
The face carries four potentiometers in two pairs. The t1 pair sets the time the output stays picked up and the t2 pair sets the time it stays released, and each pair is a range dial plus a percentage dial for fine trim. Both sides cover 0.1 second to 10 days, so a cycle can run 30 seconds on and 6 hours off from one module. Setting deviation is 10% and repeat accuracy 0.2%, which holds the duty steady across a shift.
Why Asymmetry Matters
A symmetric cycler forces the on time to equal the off time, so a duty of one part in ten is not reachable. With t1 and t2 on separate dials the ratio is free, and the relay keeps cycling for as long as the supply is present. Reset takes 200ms at most, so a brief supply dip restarts the cycle cleanly instead of leaving it mid-step.
Supply and Contact
A1 and A2 take AC or DC from 12 to 240V at 50 or 60Hz, with a tolerance of -15% to +10% and a burden of 0.09 to 3VA on AC or 0.05 to 1.7W on DC. The S terminal beside the supply pair takes the control circuit. The output is a changeover contact on 15, 16 and 18 rated 16A at AC1, switching 250V AC or 24V DC, with a minimum breaking capacity of 500mW. The two contact version of the same frame is the WTT8-S2.
Panel Fit
One 18mm module of 90mm depth clips to a 35mm rail. The face is IP40 and the terminals IP20, overvoltage category III at pollution degree 2, rated -20°C to +55°C. Terminals take one 2.5mm² or two 1.5mm² conductors at 0.4N·m, and mechanical life is 10 million operations against 100,000 electrical at AC1. A green lamp shows the supply and a red lamp shows the output state. The body carries CE and CCC marking. Send your on time, off time and quantity to WTAIELE for a quote.
