Residual Current Device (RCD), Residual-Current Circuit Breaker (RCCB), Ground Fault Circuit Interrupter (GFCI), Ground Fault Interrupter (GFI), or an Appliance Leakage Current Interrupter (ALCI). The exact wording of the term varies from country to country.
Questions tagged [rcd]
38 questions
11
votes
3 answers
How do I protect myself when testing a PCB that involves an AC line?
I have to test prototype PCBs that convert household AC into several DC voltage levels.
I concern about my safety when working with AC and would like to know how to properly setup a testbench that, for example, will trip a circuit breaker or break a…
Natthapol Vanasrivilai
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2
votes
1 answer
Inverter causing RCD to trip
I have an offgrid inverter/charger - an MPPSolar PIP4048MS (4000W inverter, 48V system). By and large it has worked well for 7 years.
Recently I bought an MPPSolar PIP5048MS (5000W inverter, 48V system) as a replacement.
However, it keeps on…
user1273784
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2
votes
1 answer
Is it OK to use a 2 pole RCD on each Line of an unbalanced 3 phase installation
I have a building that is mains supplied, but has a 3 phase back up generator-- black outs are almost daily here. There is no 3 phase equipment in use.
The current instillation is about 12kva, but the 4 pole RCD being used is too small. We don't…
SV Savannah
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2
votes
0 answers
How to check if Neutral is grounded properly?
I was thinking of buying a Residual current device but I don't know if the power supply to my home is grounded properly or not. For initial testing I used my multimeter to check the voltage coming to my home. It was 220 V.
Then I checked each…
Hemant Yadav
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2
votes
2 answers
Automatic Self-Test Circuit in GFCI outlet
What kind of self-test circuits or method do they used in the GFCI outlets generally? Is it just firmware or is there a physical addition (and what it is usually?)
This is because after 2015, it is required by UL. But there were many old stocks…
Samzun
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2
votes
4 answers
Why do RCDs / GFCIs sense differentially rather than directly?
As far as I know, all RCDs / GFCIs sense leakage current by differential measurement between active and neutral with a current transformer. Both the active and neutral wires will pass through the transformer.
I have tried without success to find…
user133493
1
vote
4 answers
Why can a raclette grill with over 400kOhm resistance between phase and null against earth trigger a 30mA RCD in a 230VAC network?
I have a 1.2kW 230V~1AC raclette grill which triggers 30mA RCDs, probably when the bi-metal temperature controller turns it off.
Not to repair, but to get better in failure mode understanding and root-cause analysis, I started to take some…
Torsten Knodt
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1
vote
1 answer
Investigating RCD nuisance tripping when ACCL changes power source
My apartment is supplied with 2 sources of electricity: the grid and a generator in the apartments premises. The change over is controlled by an ACCL. The apartment has an 25A ELCB/RCCB with 100mA sensitivity. The power to individual rooms is…
Nikhil
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1
vote
1 answer
Why is there a fuse in this RCCB (RCD)?
I supposed there is a sense coil inside the RCCB (RCD)of this tankless water heater. But why is there a fuse inside one of the load side to the circuit? Isn't the round circle the sense coil where the 2 load wire passes? Why isn't the fuse in one of…
Jtl
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1
vote
1 answer
RCD "Clamp/Snubber"
I am attempting to figure out this "RCD Snubber" as seen below:
The Eval Sheet says "The resistor capacitor diode (RCD) snubber for the two
synchronous rectifiers consists of R3, C29, and D4 for one SR,
and D3, C30, and R35 for the other SR."…
Carlo
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1
vote
2 answers
Selecting residual current for RCBO
I'm creating a portable test socket for electrical appliances that comes equip with a RCBO, power meter and possibly emergency stop button. My test socket will operate at max 240V AC and 10A. The purpose of the RCBO is to protect myself when I'm…
Max
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1
vote
2 answers
RCD Live and Neutral Protection
I understand that an RCD device helps to provide protection against electric shocks when completing a circuit between Live and Earth wires, where the Neutral and Earth wires are separated before being wired into the consumer-unit/distribution-panel.…
Algebrator
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1
vote
4 answers
Trip RCD with a circuit
I am wondering if it is possible to trip an RCD safely with a custom circuit.
I know the RCD detects current leaking to ground, so could a relay and a resistor be used to short the active to ground? I want to make a form of emergency stop that can…
jdm
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1
vote
1 answer
How do RCD Testers work?
RCD-Testers can be used to check if the residual current device (RCD) of the installation is properly working. How to they do this?
I want to build my own RCD-tester. Which circuit can be used to generate a certain fault current? (e.g. 30mA AC or…
Michael Haar
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1
vote
1 answer
Using a residual current device when there is an isolation transformer
In a system, currently there is no circuit breaker and RCD, but there is an isolation transformer as in the diagram below:
simulate this circuit – Schematic created using CircuitLab
As you see the transformer has no earth wire connection.
What…
user1999
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