Asymmetric Cycler Timer Relay WTT8-S1
WTT8-S1 asymmetric cycler timer relay with separate ON and OFF times set on four dials, 0.1 second to 10 day range, AC/DC 12-240V and one 16A SPDT contact.
Time Relay
Time delay relays for sequential control, delayed start/stop, and timed switching in automation panels.
Time Relay products
Power-on Delay Relay WTA1
WTA1 power-on delay relay, 0.1 second to 10 day delay range, AC/DC 12-240V supply, one 16A changeover contact in an 18mm DIN rail module.
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Send what has to happen and when, plus the control voltage. We reply within 24 hours with the model, the time range and the terminal diagram.
TIME RELAYS
Time Relays for Delay, Cycling and Pump Alternation
A time relay is a contact that closes late. The coil is energised, a timer counts, and only then does the contact change state. That delay is what lets a panel start a second pump after the first has proved pressure, or hold a compressor off until the refrigerant pressure has equalised.
The WTT8-B1 gives one delay function, the WTT8-S1 cycles with separate on and off times, the WTM1 is multifunction with the mode selected on the front, and the WTA1 delays the start after power is applied. All four take AC or DC 12 to 240 V and switch 16 A at 250 V AC.
Delay ranges cover fractions of a second up to hours, set on the front dial. Units carry CE and CCC marking.
Time Relay Functions
Choose the function before the range. Most panels need one of four: a start delay, a cycling duty, a sequence step, or a power-on hold-off.| Model | Function | Supply | Where it is used |
|---|---|---|---|
| WTT8-B1 | Single delay | AC/DC 12–240 V | Fan run-on, valve stroke |
| WTT8-S1 | Asymmetric cycler | AC/DC 12–240 V | Pump alternation, dosing |
| WTM1 | Multifunction | AC/DC 12–240 V | Sequence steps |
| WTA1 | Power-on delay | AC/DC 12–240 V | Compressor restart lockout |
Wiring notes
- A1 and A2 are the supply, and the contact is usually 15 common, 16 normally open, 18 normally closed.
- The timer runs on its own supply, not on the load current, so a 16 A contact can switch a contactor coil without the timer seeing the motor current.
- For a cycling duty, set the on and off times separately; a symmetric timer set to 50 percent is not the same as a cycler with different periods.
COMMON QUESTIONS
Frequently Asked Questions
A1 and A2 take the supply. The contact is 15 common with 16 normally open and 18 normally closed on the common 8-pin base. The load or contactor coil goes through 15 and 16 for a delay-on-contact.
On-delay starts timing when the supply is applied and changes the contact after the set time. Off-delay keeps the contact in its operated state for the set time after the supply is removed. The WTA1 is a power-on delay, which is the on-delay case.
In a circuit diagram it is a coil with a clock or a square with a diagonal, and the contact carries a small arc or clock symbol to show the delay. The terminal numbers 15/16/18 are the practical identifier in a panel.
It can, if it switches the two contactor coils in turn, but the WTT8-S1 is the purpose-built asymmetric cycler for that duty. A multifunction relay can do it too, with more settings to get wrong.
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