How to Enable or Disable ERMS Setting on STU

How to Enable or Disable ERMS on P and S Type Trip Units (with LCD Touchscreen)

🔎 Note: This guide applies only to P-type and S-type trip units, as they feature an LCD touchscreen interface.

If you are testing ERMS (Energy-Reduction Maintenance Setting) functionality or need to enable/disable ERMS settings, follow the steps below:

Step-by-Step Instructions:

Step 1: Power up the Trip Unit

There are several ways to power the trip unit.
In the example shown, a USB-A to Mini-B cable is used to power the unit from a laptop.

Step 2: Navigate to “Relay Set”
On the home screen, tap the “Relay Set” icon located in the top right corner.

Step 3: Access ERMS Settings
Press the right arrow button to scroll through settings until you reach settings 23–27, which include ERMS-related options.

Step 4: Select the Desired ERMS Setting

Choose the specific ERMS setting you want to change.

For example, to enable ERMS Instantaneous Protection Setting, select ERMS_I.

Step 5: Change the “Use” Setting
In the “Use” section, change the value from “Not Use” to “Use” to activate the function.

Step 6: Confirm the Change
After making your selection, press Enter (arrow button highlighted in the red box below).
When prompted with “Do you want to change the value?”, press “OK” to confirm.

Step 7: Verify the Setting Is Active
If the setting was successfully enabled, the display for that setting will light up blue, indicating that it is now active.