P
perlenmann28 Mar 2013 11:48Hello,
I wanted to ask, since 2009 all sockets (that can be operated by a layperson) must be protected by an RCD.
According to DIN standards, should everything be connected to a single RCD? Or does the electrical system need to be distributed across multiple RCDs?
I wanted to ask, since 2009 all sockets (that can be operated by a layperson) must be protected by an RCD.
According to DIN standards, should everything be connected to a single RCD? Or does the electrical system need to be distributed across multiple RCDs?
S
syrincsandy29 Mar 2013 09:57Hello, the DIN standard regulates this according to the equipment variant. However, almost every distribution system operator (DSO) requires at least 2 RCDs (residual current devices) in their technical connection conditions (TCC). Also, the heating system should be protected either without or, if required, with a separate RCD.
Best regards, Andy
Best regards, Andy
H
Harlekinz10 Aug 2013 14:01As far as I know, some distribution network operators (DNOs) require at least two RCDs (residual current devices) instead of just one main RCD.
The question is: what type of property (size, number of circuits) needs to be protected by RCDs? Actually, it’s the people who are being protected.
What is your budget? How much space do you have in your distribution board?
If my information is still correct (I have not been directly involved in electrical work since 2010), you can designate individual circuits and don’t need to install an RCD upstream (for example, sockets for heating or a chest freezer). However, only those particular devices are allowed to be operated on those circuits.
I am currently working on a renovation plan for my own (possibly) house and am planning: one 4-pole RCD for the kitchen, one 4-pole RCD for the hallway + living room + bedroom + dressing room, one 2-pole RCD for the bathroom and toilet, one 2-pole RCD for the study (unfortunately with a balcony, which can only be separated with a lot of effort), one 4-pole RCD for the basement, and one 2-pole RCD for the garden.
Circuits without RCD protection are planned for the chest freezer and heating.
The house has 130 sqm (1400 sq ft) of living space over two floors and a full basement.
This is just an example; normally the number of RCDs wouldn’t be this high, but as a man, I’m allowed to have this quirk.
Best regards,
Markus
The question is: what type of property (size, number of circuits) needs to be protected by RCDs? Actually, it’s the people who are being protected.
What is your budget? How much space do you have in your distribution board?
If my information is still correct (I have not been directly involved in electrical work since 2010), you can designate individual circuits and don’t need to install an RCD upstream (for example, sockets for heating or a chest freezer). However, only those particular devices are allowed to be operated on those circuits.
I am currently working on a renovation plan for my own (possibly) house and am planning: one 4-pole RCD for the kitchen, one 4-pole RCD for the hallway + living room + bedroom + dressing room, one 2-pole RCD for the bathroom and toilet, one 2-pole RCD for the study (unfortunately with a balcony, which can only be separated with a lot of effort), one 4-pole RCD for the basement, and one 2-pole RCD for the garden.
Circuits without RCD protection are planned for the chest freezer and heating.
The house has 130 sqm (1400 sq ft) of living space over two floors and a full basement.
This is just an example; normally the number of RCDs wouldn’t be this high, but as a man, I’m allowed to have this quirk.
Best regards,
Markus
For Safety
The RCD
The RCD (Residual Current Device) is a personal protection switch designed for your own safety.
The standard type to install is a 40A, 30mA version.
Here, 40A is the maximum current allowed to flow through the RCD, and 30mA is the maximum fault current at which it must trip.
An RCD with >30mA is not permitted.
One RCD for the entire house is not sufficient; don’t let your electrician tell you otherwise.
A sensible distribution could be, for example:
1 RCD for sockets
1 RCD for lighting
1 RCD for building technology
1 RCD for refrigeration units
1 RCD for outdoor areas including garage/carport
Why all this effort?
If you only have one RCD and a fault occurs, you will be left in the dark over your entire property. That is very inconvenient.
By separating sockets and lighting, there will always be some light functioning somewhere.
The outdoor area should also always be protected by a separate RCD because moisture can cause faults.
RCDs for building technology and refrigeration units are not strictly necessary but provide a significant advantage, for example, to protect your frozen goods during summer vacations if the sockets in the living room fail; the same applies in winter for heating systems.
For permanently connected appliances (i.e., not connected via a socket), no RCD is required.
The Circuit Breakers
Circuit breakers protect the connected wiring from overload to prevent overheating and potential damage. They are not sufficient as personal protection devices (hence the need for RCDs).
For private use, miniature circuit breakers with B-characteristic are typically used. The “B” refers to the tripping behavior, in this case 5 times the rated current (5xIn).
Example 1:
A 16A breaker is installed. If a short circuit occurs, a current of 5 x 16A = 80A flows, and the breaker trips immediately.
Example 2:
You have accidentally pierced the cable but only scratched it slightly, causing leakage currents between Live and Neutral. The current is still below 5 x 16A, so the breaker will not trip immediately but will warm up and switch off after some time.
This timing is defined by the “B” characteristic and can be read from graphs. This delay is also why miniature circuit breakers are not approved as personal protection devices.
Breaker sizing
Circuit breakers should be at least matched to the cross section of the wiring behind them but ideally adapted to the intended use.
For example, I use 16A breakers for sockets and 6A or 10A breakers for interior lighting.
The reason for this differentiation is the tripping time mentioned earlier.
Maximum 10 sockets per 16A breaker. This is related to the diversity factor.
I learned that an average of 300 W is consumed per socket. A 16A breaker can handle up to 3000 W, hence 10 sockets.
Each room is protected by a separate breaker. A breaker costs roughly €1, so don’t let yourself be persuaded to pay a much higher price. But keep in mind that this means each room also gets its own supply line.
The same applies to lighting. Each room has one breaker, so generally you don’t need to worry much about the number of breakers. One should be sufficient unless you plan to install 1000W floodlights.
Large appliances such as washing machines, dryers, refrigerators, dishwashers, ovens, cooktops, automatic coffee machines, etc., each get their own breaker.
Especially devices with more than 2kW power. For loads above 3kW (instantaneous water heaters), a 16A breaker is no longer sufficient, and the supply wiring must be dimensioned larger.
As you can see, quite a lot adds up, so make sure to plan for a larger main distribution board.
An additional empty meter slot can also be advantageous (for future upgrades like a heat pump or photovoltaic system).
The RCD
The RCD (Residual Current Device) is a personal protection switch designed for your own safety.
The standard type to install is a 40A, 30mA version.
Here, 40A is the maximum current allowed to flow through the RCD, and 30mA is the maximum fault current at which it must trip.
An RCD with >30mA is not permitted.
One RCD for the entire house is not sufficient; don’t let your electrician tell you otherwise.
A sensible distribution could be, for example:
1 RCD for sockets
1 RCD for lighting
1 RCD for building technology
1 RCD for refrigeration units
1 RCD for outdoor areas including garage/carport
Why all this effort?
If you only have one RCD and a fault occurs, you will be left in the dark over your entire property. That is very inconvenient.
By separating sockets and lighting, there will always be some light functioning somewhere.
The outdoor area should also always be protected by a separate RCD because moisture can cause faults.
RCDs for building technology and refrigeration units are not strictly necessary but provide a significant advantage, for example, to protect your frozen goods during summer vacations if the sockets in the living room fail; the same applies in winter for heating systems.
For permanently connected appliances (i.e., not connected via a socket), no RCD is required.
The Circuit Breakers
Circuit breakers protect the connected wiring from overload to prevent overheating and potential damage. They are not sufficient as personal protection devices (hence the need for RCDs).
For private use, miniature circuit breakers with B-characteristic are typically used. The “B” refers to the tripping behavior, in this case 5 times the rated current (5xIn).
Example 1:
A 16A breaker is installed. If a short circuit occurs, a current of 5 x 16A = 80A flows, and the breaker trips immediately.
Example 2:
You have accidentally pierced the cable but only scratched it slightly, causing leakage currents between Live and Neutral. The current is still below 5 x 16A, so the breaker will not trip immediately but will warm up and switch off after some time.
This timing is defined by the “B” characteristic and can be read from graphs. This delay is also why miniature circuit breakers are not approved as personal protection devices.
Breaker sizing
Circuit breakers should be at least matched to the cross section of the wiring behind them but ideally adapted to the intended use.
For example, I use 16A breakers for sockets and 6A or 10A breakers for interior lighting.
The reason for this differentiation is the tripping time mentioned earlier.
Maximum 10 sockets per 16A breaker. This is related to the diversity factor.
I learned that an average of 300 W is consumed per socket. A 16A breaker can handle up to 3000 W, hence 10 sockets.
Each room is protected by a separate breaker. A breaker costs roughly €1, so don’t let yourself be persuaded to pay a much higher price. But keep in mind that this means each room also gets its own supply line.
The same applies to lighting. Each room has one breaker, so generally you don’t need to worry much about the number of breakers. One should be sufficient unless you plan to install 1000W floodlights.
Large appliances such as washing machines, dryers, refrigerators, dishwashers, ovens, cooktops, automatic coffee machines, etc., each get their own breaker.
Especially devices with more than 2kW power. For loads above 3kW (instantaneous water heaters), a 16A breaker is no longer sufficient, and the supply wiring must be dimensioned larger.
As you can see, quite a lot adds up, so make sure to plan for a larger main distribution board.
An additional empty meter slot can also be advantageous (for future upgrades like a heat pump or photovoltaic system).
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