Applies To

Intermatic ET2000 Series (ET Basic Plus) Electronic Time Switches with two or four circuits, including ET2125, ET2145, ET2725, ET2745, ET2825 and ET2845 models (all enclosure variants).

Question / Problem

How do I configure an ET2000 Series timer to control a latching lighting contactor?

Answer

A latching contactor requires two circuits on the timer to operate: one circuit sends a pulse to close (latch) the contactor and a second circuit sends a pulse to open (unlatch) the contactor. The timer must be set to PUL (pulse) output mode to generate these signals.

Circuits are paired in fixed groups when configured for PUL mode:

• Circuits 1 and 2 Form One Pair — Circuit 1 sends the ON pulse and Circuit 2 sends the OFF pulse
• Circuits 3 and 4 Form a Second Pair — Circuit 3 sends the ON pulse and Circuit 4 sends the OFF pulse

Each pair controls one or more latching contactors. A 2-circuit timer can control one group of latching contactors. A 4-circuit timer can control up to two groups of latching contactors. No other circuit pairing combinations are available in PUL mode.

The output configuration can only be set during initial power-up or after performing a Clear Time Switch Memory (MEMCLR) operation. If the timer is already programmed, the memory must be cleared first.

Step-by-Step Resolution

Clearing Time Switch Memory (if Needed)

If the timer has already been configured and you need to change the output mode to PUL, perform a memory clear first. This resets all programmed settings to factory defaults and erases all existing schedules.

1. Press and Hold ENTER/NEXT

   Do not release ENTER/NEXT until the memory clear operation is completed.

2. Press and Release the RESET Button

   While continuing to hold ENTER/NEXT, press and release the round RESET button on the circuit board.

3. Wait for the Memory Clear to Complete

   Continue to hold ENTER/NEXT until MEMCLR and then DONE appear on the display. Release ENTER/NEXT.

Setting the Output Configuration to PUL

The output configuration screen is only accessible on a factory-new timer at first power-up or immediately after a Clear Time Switch Memory (MEMCLR) operation. If the timer has already been configured, you must perform the MEMCLR procedure above before these steps will appear.

1. Verify IND Is Displayed

   After initial power-up or a memory clear, the display shows IND and the load icons for Circuits 1 and 2 turn on. This indicates the timer is ready for output configuration.

2. Select PUL for the First Circuit Pair

   Press + or - to scroll from IND to PUL. The display shows PUL, indicating a 2-second pulse output for Circuits 1 and 2.

3. Confirm the First Circuit Pair

   Press ENTER/NEXT to save the PUL setting for Circuits 1 and 2.

4. Configure the Second Circuit Pair (4-Circuit Models Only)

   The display shows IND and the load icons for Circuits 3 and 4 turn on. Press + or - to scroll to PUL if you need a second latching contactor pair. If you do not need a second pair, leave it set to IND or select the desired output mode for Circuits 3 and 4.

5. Confirm the Second Circuit Pair

   Press ENTER/NEXT to save the setting. The output configuration is now complete.

6. Program Your Schedule

   With PUL mode active, program ON and OFF events for the circuit pair. Each ON event triggers a 2-second pulse on the first circuit in the pair (latching the contactor). Each OFF event triggers a 2-second pulse on the second circuit (unlatching the contactor).

Tips / Additional Notes

• The PUL output sends a 2-second pulse each time a scheduled event occurs. The contactor must be a latching type that holds its position after the pulse ends. Standard (non-latching) contactors require continuous power and should use the IND output mode instead
• You can control more than one latching contactor on the same circuit pair as long as the combined load does not exceed the load rating of the timer. On 2-circuit models (ET2125, ET2725, ET2825) only one circuit pair is available. On 4-circuit models (ET2145, ET2745, ET2845) two circuit pairs are available