How Can I Verify That the NCB Plug Is Working?Updated 6 hours ago

Ensure your NCB (Nuisance Current Blocker) is functioning properly by testing three key areas: stopping contact current, filtering dirty electricity, and maintaining a ground-fault path.

1. Stop Contact Current

Tools Needed: Fluke 287 or 289 multimeter, outlet tester

1. Use a three-prong tester to confirm your outlet is grounded and wired correctly.

2. Plug your grounding mat into the NCB-controlled outlet.

3. Set the Fluke to measure microamps (μA).

4. Place the black lead on the mat’s metal connector and hold the red lead.

5. Record the reading:

   • < 1 μA: NCB is working.

   • Occasional flickering <0.1 μA is normal (Fluke provides two decimal places) .

   
   

6. If > 1 μA, turn the internal dial fully clockwise and retest.

2. Filter Dirty Electricity

Tools Needed: Fluke multimeter

1. Set the multimeter to millivolts (mV).

2. Connect F1 to Hz function to measure frequency on grounding conductor.

3. Measure before unplugging the NCB, then after connecting it.

4. A noticeable reduction in high-frequency noise confirms the NCB is filtering dirty electricity .

3. Confirm Ground-Fault Path

Important: Only perform this with a qualified professional!

1. Confirm NCB Pro is installed inline with equipment grounding conductor.

2. Use a Fluke to check for ≥ 1 MΩ resistance through the NCB Pro .

3. With the circuit powered down, tie hot and ground conductors together downstream of the NCB.

4. Restore power; the breaker should immediately trip, indicating a working ground-fault path .

5. If it doesn’t trip, the breaker—not necessarily the NCB—is faulty. Test another breaker or replace.

Why These Tests Matter

• Contact Current: Prevents tiny electric currents from reaching your body through grounding products.

• Dirty Electricity: Removes high-frequency voltage spikes riding on grounding conductors.

• Ground-Fault Safety: Ensures any fault current trips your breaker, protecting against shock.

FAQ

Can I test myself at home?

Yes—steps 1 and 2 use a multimeter and outlet tester. Step 3 requires professional oversight.

What multimeter is recommended?

A Fluke 287 or 289 is ideal for its microamp and frequency measurement capabilities .

Conclusion

Verifying your NCB in these three areas confirms it’s protecting you from contact current, filtering dirty electricity, and ensuring a safe ground-fault path. If any test fails, adjust the dial, test another circuit, or consult an electrician.

If you still have questions or safety concerns, feel free to reach out to SYB support.