WiremanWireman · Several GFCIs trip together: troubleshooting for electricians · 2023 NEC ·
Several GFCIs trip together
Map which GFCI feeds which, then look for shared neutrals, moisture or one leaky appliance.
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How it works
A GFCI compares the current going out on the hot with the current coming back on the neutral, and trips when about 5 mA goes missing (4 to 6 mA for the Class A devices used in homes). It also protects everything wired to its LOAD terminals, which can include other GFCIs. When several trip at once, they’re usually in a chain, sharing a neutral they shouldn’t, or all seeing the same moisture or surge.
Every question and answer in this guide. Tap “Step by step” to walk through it.
- Test: Map which GFCI protects what
- One GFCI feeds the othersAfter a trip, are the downstream GFCIs actually tripped, or just dead?
- Only the first one is trippedOne GFCI protecting a chain
- Several are tripped themselvesGFCIs wired in series
- They’re on separate circuitsWhen do they trip together?
- In rain or when sprinklers runWater getting into outdoor wiring
- During storms or when the lights blinkA surge or utility disturbance
- When one appliance runsTest: Check for shared or crossed neutrals
- Neutrals are shared or crossedA neutral shared between GFCI circuits
- Each circuit has its own neutralOne appliance leaking current to ground
- One GFCI feeds the othersAfter a trip, are the downstream GFCIs actually tripped, or just dead?