Applies To
Intermatic ET2000 Series (ET Basic Plus) four-circuit timers: ET2145C/CP/CR, ET2745C/CP/CR, and ET2845C/CP/CR.
Question / Problem
Can a four-circuit ET2000 Series timer be used for multiple latching lighting contactors?
Answer
A four-circuit ET2000 Series timer can control a maximum of two groups of latching lighting contactors when configured for pulse (PUL) output mode.
A latching contactor requires two separate pulse signals to operate: one circuit sends the ON pulse to close (latch) the contactor, and a second circuit sends the OFF pulse to open (unlatch) the contactor. Because each latching contactor requires two dedicated circuits, a four-circuit timer can only control two groups of latching contactors:
- Circuits 1 and 2 operate the first latching contactor group. Circuit 1 sends the ON pulse and Circuit 2 sends the OFF pulse.
- Circuits 3 and 4 operate the second latching contactor group. Circuit 3 sends the ON pulse and Circuit 4 sends the OFF pulse.
No other circuit pairing combinations are available in the PUL operating mode.
The output configuration can only be set during initial startup of the timer or after performing a Clear Time Switch Memory operation. If the timer is already running, you must clear the memory first to access the output configuration setup.
Step-by-Step Resolution
Clearing Time Switch Memory
A Clear Time Switch Memory operation resets all programmed settings to their factory default values. After the reset, the display will briefly show the model number, USB boot loader version, EE boot loader version, firmware revision, and reset reason code. MEMCLR is displayed, followed by DONE when the operation is completed.
Press and Hold ENTER/NEXT
Do not release ENTER/NEXT until the memory clear operation is completed.
Press and Release the RESET Button
While continuing to hold ENTER/NEXT, press and release the round RESET button.
Wait for the Memory Clear to Complete
Continue to hold ENTER/NEXT until MEMCLR and then DONE briefly appear on the display.
Confirm IND Is Displayed
The display will show IND, indicating the timer is ready for output configuration. Refer to Setting the Output Configuration below.
Setting the Output Configuration
Verify IND Is Displayed
Apply power to the time switch. The display shows IND, the arrow icon above the ENTER/NEXT button illuminates, and the load icons for Circuit 1 and Circuit 2 turn on. If IND does not appear, a Clear Time Switch Memory operation must be performed first.
Select the Output Mode for Circuits 1 and 2
Press + or - to scroll to PUL (2-second pulse) for latching contactor operation.
Save the Setting for Circuits 1 and 2
Press ENTER/NEXT to confirm the output configuration for the first circuit pair.
Configure Circuits 3 and 4
The display now shows IND and the load icons for Circuit 3 and Circuit 4 turn on. Press + or - to scroll to PUL for the second latching contactor.
Save the Setting for Circuits 3 and 4
Press ENTER/NEXT to confirm the output configuration for the second circuit pair.
Complete the Configuration
The output configuration is now set. The timer will use 2-second pulses on each circuit pair to control the latching contactors.
Tips / Additional Notes
- In the PUL operating mode, circuits are always paired: Circuits 1 and 2 form one pair and Circuits 3 and 4 form another pair. No other pairing combinations are available.
- Each circuit pair can be configured independently. One pair can be set to PUL while the other pair is set to a different output mode such as IND (independent) if only one latching contactor is needed.
- The output configuration setup screen is only accessible during initial power-up or after a Clear Time Switch Memory operation. To change the output mode on a timer that is already programmed, the memory must be cleared first, which will erase all existing schedules.