TIMING MODES OF OPERATION

Selecting the correct Mode of Operation (timing function) can be as easy as answering three questions. If you have problems answering these questions, try drawing a ladder diagram that illustrates yur verbal desription of the systems operation. Written descriptions of the five most popular Modes of Operation are also included after the chart. If you can't find the Mode of Operation using this text, SSAC's Application Engineers provide free technical information and product selection assistance. Phone (315) 638-1300 FAX (315) 638-0333. You may also contact T&C Industrial Controls, Inc. at (818) 240-3600 FAX (818) 547-9359 Email: tcindust@flash.net for sales or technical assistance.

Selection Questions

1) The timing starts when the initiate (starting) contacts are?
A) Closed B) Opened
2) What is the status of the output (or load) during timing?
A) On B) Off C) On/Off
3) Will the load de-energize (or remain de-energized) if the initiate (starting) contacts are opened during timing?
A) Yes B) No

MODES OF OPERATION

DELAY ON MAKE
(On Delay, Delay on Operate, Operate Delay, Prepurge Delay)

OPERATION: Upon application of power, the time delay begins. The output is de-energized before and during the time delay, the output is energized (relay is transferred) and remains energized until power is removed.

RESET: Removing power resets the time delay and output.

INTERVAL
(On Interval, Interval On, Pulse Shaping, Bypass Timing)

OPERATION: Upon application of power, the time delay begins. The output is energized (relay is transferred) during the time delay. At the end of time delay the output is de-energized and remains de-energized until power is removed.

RESET: Removing power resets the time delay and the output.

RECYCLING
(Recycle Timing, Repeat Cycle, Duty Cycling)

OPERATION: Upon application of power, the output is energized (relay is transferred) and the ON time begins. At the end of the ON time, the output de-energizes and the OFF time begins. At the end of the OFF time, the output is energized (relay transferred) and the cycle repeats as long as power is applied. The OFF time may be the first delay in some recycling timers.

RESET: Removing power resets the time delays, and returns the sequence to the first delay.

SINGLE SHOT
(One Shot Relay, Single Shot Interval, Pulse Shaping)

OPERATION: Power must be applied to the input before and during timing. Upon momentary or maintained closure of the initiate switch (leading edge triggered), the output is energized (relay is transferred) for a measured interval of time. At the end of the delay, the output de-energizes. Opening or reclosing the initiate switch during timing has no effect on the time delay.

RESET: Reset occurs when the time delay is complete and the initiate switch is opened. Loss of power resets the time delay and output.

DELAY ON BREAK
(Off Delay, Release Delay, Delay on Release, Postpurge Delay)

OPERATION: Power must be applied to the input before and during timing. Upon closure of the initiate switch, the output is energized (relay is transferred). The time delay begins when the initiate switch is opened (trailing edge triggered). The output remains energized during timing. At the end of the time delay, the output is de-energized.

RESET: Reclosing the initiate switch during timing resets the time delay. Most delay on break timers reset on loss of power.

Distributed by: T&C Industrial Controls, Inc.
1121 N. Cedar St. * Glendale, CA 91207 USA
(818) 240-3600 * FAX (818) 547-9359
Email to: tcindust@flash.net

Manufactured by: SSAC Inc.
P.O. Box 1000 * Baldwinsville, NY 13027
(315) 638-0333 * FAX (315) 638-7158