FAQs
Below you will find questions and answers concerning general topics or specific product groups. Click on a category to view the related questions and answers.
General
Yes, they do. The tender texts can be found on our website on the specific page for the product in question. Our product catalogue at www.ausschreiben.de also contains tender texts.
In the download section of the respective product page, you will find derating diagrams. They show the permissible load capacity of our switches at different ambient temperatures.
e.Guard
Doepke e.Guard is a smart, modular system for condition monitoring of electrical installations with intelligent residual current monitoring. Frequently asked questions and answers about our e.Guard portfolio can be found at https://www.doepke.de/en/eguard-faq.
Arc-fault detection devices
No, unlike the two-pole arc-fault detection devices, four-pole AFDDs are not included in the DIN VDE 0100-420 standard (protection against thermal effects). Two-pole AFDDs are recommended here because the number of electrical devices without protective conductors has grown rapidly in recent years. With these devices, the risk of undetected arc faults, and hence the risk of fire, is far greater. Hence special AFDD devices to detect all kinds of arc faults (serial and parallel) are recommended. Continues to apply for a five-strand cable: Residual current protection is fire protection when residual current circuit breakers with an upper tripping limit of 300 mA are used for conventional fire protection.
Yes, DAFDDs from Doepke are supplied on the input side from below. There is one insensitive input side and one output side. The neutral conductor position however can be selected to be left or right.
Residual current circuit-breakers
The use of type AC residual current circuit-breakers is not permitted in Germany. These products are purely intended for export. Installation regulations VDE 0100-510 and VDE 0100-410, from 1983, were the first regulations to stipulate that RCDs in use had to be sensitive to both AC residual currents and to pulsating DC residual currents (now known as Type A). There was a transition period until 1985 for installations that were being planned or constructed; since then use of Type AC residual current circuit-breakers has no longer been permitted in Germany.
There is no definition of the term ‘existing protection’ in the relevant DIN VDE standards, or in the ‘International Electrotechnical Vocabulary’ (IEV). The term originally comes from public-sector building regulations and describes a circumstance in which the original form of an approval continues to apply even if newer laws impose more stringent requirements when it comes to gaining the same approval. As a general rule, the latest installation regulations apply to new installations. For example, a residual current circuit-breaker with a rated residual current ≤ 30 mA is the minimum requirement for a new socket (up to 32 A). A professional electrician should carry out a safety assessment to determine whether it is necessary to replace the existing installation or not. This in turn will determine whether the installation has any ‘existing protection’ at all. To get an answer, it is important first to know the date on which the electrical installation was installed and what installation regulations were in force at the time. Modifications required by the standards and their time limits should then be known. In the event that the electrical installation was designed in line with the regulations of the time, it must be clarified whether or not adjustments to meet current requirements are required for other reasons. The bottom line, however, is that safety, reliability and use of the electrical installation always take priority over the existing protection.
After tripping, the switch toggle must first be moved to the zero position (down) before the residual current circuit-breaker can be switched on again. This is due to the integrated reset function of our DFS 2, DFS 4, and DFS 6 series: when tripped, the switch toggle remains in the centre position and is protected against direct reactivation. Only by deliberately moving it to the zero position is the mechanism reset. Your advantage: the position of the toggle allows you to immediately see whether the RCCB was switched off due to a fault (centre position) or intentionally switched off manually (zero position).
This depends on the DFS version. With our devices in the classic N-left design, operation without a neutral conductor is also possible. With devices in the N-right design, however, this is not intended because the test button does not function without a connected neutral conductor.
Based on the total current principle, this will work for all switches in the DFS series with regard to residual current detection. To ensure the test key functions correctly, however, the operating voltage range of the test circuit must be observed (this can be found in the data sheet). As the test key resistance for an N-left device is between two phases, the voltage range is greater than with N-right devices for which the test key resistance is between the neutral conductor and phase.
No. According to the standard, automatic restart is only permitted in areas where only trained electricians have access.
Yes, a DRCCB 5 ST has a bypass that is active for the short time in which the switch ‘presses the test button itself’ every month. The main contacts are isolated but the bypass maintains the voltage supply. The major benefit of this is that work can be continued easily in offices for example, and that the defaults of devices are retained (programming work and date/time). To guarantee the safe use of electricity during the test phase, the bypass also has residual current protection. If a residual current occurs in the system the moment the self-test runs, the DRCCB 5 ST triggers as normal.
Our DRCCB 5 ST are certified to DIN VDE 61008-1 and so are also permitted in private installations.
Our DFS 4 A EV is a switch with residual current characteristic A, and an additional DC residual current detection function that restricts DC faults to max. 6 mA. Detection of sinusoidal AC currents and pulsating DC residual currents is mains-voltage-independent; the DC additional function is voltage-dependent. The DFS 4 A EV are designed specifically for use in charging stations for electric vehicles. They are not permitted for protecting installations in which electronic equipment may cause residual currents with frequencies not equal to 50 Hz. AC-DC sensitive residual current circuit-breakers of type B or B+, in accordance with DIN VDE 0100 installation regulations, must be used in this case.
Type A residual current circuit-breakers detect AC residual currents and pulsing DC residual currents having mains frequency 50 Hz. Type F residual current circuit-breakers also detect residual currents comprising mixed frequencies ≠ 50 Hz. You should always use a Type F residual current device when residual currents with mixed frequency components can occur. They are caused by devices with single-phase speed control for example, such as washing machines, heat pump dryers and air-conditioners. The DFS 4 F is also always a good choice when erroneous triggers of a Type A residual current circuit-breaker occur sporadically. The DFS F is short-time delayed and lightning resistant. This minimises considerably the risk of erroneous triggers by inrush currents and in thunderstorms.
Short-time delayed residual current circuit-breakers (KV) can help solve this problem. These switches have a non-response lag time of 10 ms and are more resistant to surge currents, which means that undesired trips can be avoided in most cases. This does not impede the additional protection (personal protection). As such, it is then possible to replace each ‘standard switch’ with a short-time delayed residual current circuit-breaker.
Due to their design, induction hobs can generate smooth DC residual currents or residual currents with frequencies not equal to 50 Hz. They therefore fall under electronic equipment that should be protected using a type B or B+ residual current circuit-breaker. Although at present neither the standards nor the hob manufacturers prescribe it, this approach is the best solution from a technical standpoint and is certainly our recommendation. Contact the hob manufacturer in case of doubt.
We generally recommend AC-DC sensitive residual current circuit-breakers for PV systems. In addition to faults on the DC side (string), they also detect residual currents in the intermediate circuit of the inverter.
Yes. Our DFS HP and DFS PV are specially developed for use in heat pump and photovoltaic applications. Thanks to their AC-DC sensitive design, they meet the requirements of all common heat pump and inverter manufacturers.
Regular testing of protection equipment is required by standards. We as the manufacturer recommend testing the test key at least once a year, or preferably every six months, for its intended purpose. Which test cycle is appropriate and/or prescribed will ultimately always depend on the type of installation, the ambient conditions and the applicable installation regulations for the electrical system, however. Furthermore, the guidelines and information – e.g. of professional associations or VdS – should be taken into account. Testing is successful if the residual current circuit-breaker trips when the test key is pressed. Regular function testing will increase the availability of the residual current circuit-breaker.
In the initial and repeat tests of residual current circuit-breakers, tripping thresholds and times (amongst others) must be measured to ascertain the effectiveness of the protection measure. The prerequisite is a measuring device that is suitable for AC-DC sensitive residual current circuit-breakers. This is normally the case for newer devices. The following values should be determined in the measurement: Trigger time, tripping current AC and tripping current DC rising. The product standard specifies which results are correct. When an AC residual current occurs, the residual current circuit-breaker should, at the latest, have tripped by the nominal value printed on the label. This threshold increases to 1.4 times the nominal value with pulsating or phase-controlled residual currents. For AC and DC residual current circuit-breakers, the DC threshold may be twice the nominal value. Note for the trigger time: If a device designed to trip at a residual current equal to its rated current is tested, the device must trip by 300 ms at the latest. If it is designed to trip at residual currents five times the rated current, it must trip by the usual 40 ms. The following table provides an overview of tripping currents and trigger times.
No, Doepke residual current circuit-breakers can withstand this without suffering damage. We are unable to comment on other products on the market. It must be noted here however that, for the switch measurement on the supply side, they measure into the integrated PSU. In this process, the readings are falsified, meaning no conclusions can be arrived at for the insulation resistance of the system. Residual current circuit-breakers sensitive to AC and DC must therefore be disconnected before the insulation measurement. For those not wanting to do this work and who want to save on connector clamps and screws, use our test-resistant DFS ISΩ HD residual current circuit-breaker. It is designed such that you can measure through it, thereby measuring past the PSU and thus attaining a non-falsified result.
Remote actuators
The DFA 3-3 attempts every 15 seconds to switch back on the fault current (up to three times). If it trips a fourth time, it stays in the Tripped state and the remote drive does not switch it back on.
No. According to the standard, automatic reclosing is only permitted in areas accessible exclusively to electrically instructed persons or qualified electricians. For applications outside these areas, a DFA 3-0 can instead be used to enable remote reclosing.
miniature circuit-breakers
The DLS 6 miniature circuit-breakers may be operated with direct voltage up to 60 V (single terminal) or up to 125 V (two-terminal).
Yes, the DLS 6 can be operated using other rated frequencies. Does this change the tripping factor over the frequency range though? The tripping factors over the frequency range are: 1.5 for DC; 1.0 at 50 Hz; 1.1 at 100 Hz; 1.2 at 200 Hz; 1.3 at 300 Hz and 1.4 at 400 Hz.
IEC and UL are product standards. IEC stands for International Electrotechnical Commission, UL for Underwriters Laboratories Inc. ®. IEC standards are usual in Europe and Asia, and parts of South America and Africa; UL represent the prevalent safety guidelines for North America and parts of South America and Europe (refer to the map). Our DLS 6 miniature circuit-breakers for residential, skilled trade and industrial applications are IEC-certified. Our DLS 7, 8 and 9 miniature circuit-breakers are UL-certified, and some DLS 8 types also certified to IEC - for system standardisation worldwide. There are clear differences between IEC and UL as regards content. IEC standards define minimum safety requirements of a device or system. The technical details of the constructive implementation of these requirements are left to the manufacturer. UL guidelines define very precisely how product safety is attained and where the product may be applied. Different applications are also subjected to different guidelines. Product modifications must be applied by the UL. In addition to drafting standards, the UL is also responsible for approbation, or general third-party certification and acceptance on-site. For example, factory inspections take place at device manufacturers – the purpose of which is to ensure the framework conditions defined with certification are observed.
Analysis software
The service fee for the first DRCA measurement is EUR 600, excluding statutory VAT.
Installation contactors
No, the installation contactors do not have forcibly guided contacts.
Float switches
No, the float switches are not suitable for use in extra-low voltage or direct voltage systems.
No, the floating switches are not flameproof. They must be sheathed in a special jacket, if necessary.
No, the floating switches are not suitable for use in drinking water due to the properties of their connection cables.
Residual current monitors
The DCTR B-X Hz-PoE residual current transformers detect and assess residual currents to 20 A AC and 3 A DC. Frequency-selective devices sensitive to all currents enable, across multiple channels, comprehensive configuration of frequencies and frequency ranges to analyse (from 0 to 100 KHz) The DCTR B-X Hz-PoE can be used for continual monitoring of electrical systems. Continual monitoring of residual currents can render redundant recurring insulation testing. Furthermore, residual current monitoring enables discrepancies and faults to be detected early, meaning timely intervention (preventative maintenance) is possible.
DPRCD-M
The DPRCD-M is used wherever AC-DC sensitive personal protection is required and the upstream protective measure is unknown or insufficient. As a compact module for integration into mobile distributors, it increases the level of protection in mobile applications. Typical areas of use include construction sites, rescue operations, andevent technology.
In addition to classic residual current protection, the DPRCD-M offers a wide range of additional protective functions. These include external fault current detection and fault voltage protection, as well as the detection of interrupted mains conductors, reversed mains conductors, interrupted protective conductors, and reversed protective and line conductors. An optional anticlockwise rotating field lock is also available.
The DPRCD-M detects when a Class I device (e.g., a drill) comes into contact with an active potential from another circuit. In this case, all active conductors are disconnected. The protective conductor remains connected so that the external fault current can be safely discharged.
The DPRCD-M is a module for creating a portable residual current device (PRCD). By installing it in a mobile distributor, a complete PRCD is created. The module forms the core of the device and enables AC-DC sensitive personal protection in mobile applications.
For applications in environments where particular fire risks exist, the DPRCD-M+ is recommended. With its B+ characteristic, it is optimised for applications with enhanced fire protection requirements.
The DPRCD-M is not designed for use with mobile power generators.
Yes. Currently, you can apply for funding from the German Social Accident Insurance Institution for the construction industry (BG BAU) for the purchase of a personal protection switch with DPRCD-M (status: April 2026).
Switching devices with emergency switching-off function
If you would like to use several DFS 4 NA or DHS 4 NA devices in one emergency switching-off circuit, connect the devices in parallel. The connected emergency stop buttons are wired in series. Please ensure the correct connection of the emergency switching-off contacts (S21, S22).
No. Our emergency switching-off devices do not trip during voltage interruptions. This behaviour is an essential feature of our devices and ensures reliable operation.
No. Retrofitting is not possible. If you would like to use a switching device with emergency switching-off function and remote operation, you will find the right solution in our FANA series – both as a residual current circuit-breaker (DFS 4 FANA) and as a switch disconnector (DHS 4 FANA).
Switching devices with mains monitoring
During a neutral point shift, the electrical potential at the neutral point changes, for example due to an interrupted neutral conductor under asymmetrical load. This can lead to overvoltages or undervoltages at individual loads, which may cause damage or malfunctions. NU and NUS switches detect this situation and switch off as soon as the neutral point displacement voltage reaches or exceeds 20 V. The devices switch off in less than 150 milliseconds.
No. The switches feature comprehensive mains monitoring. In addition to a neutral conductor interruption, other critical mains faults such as phase failure or asymmetrical overvoltages and undervoltages also lead to switch-off, ensuring the best possible protection for connected loads. If the neutral and line conductors are reversed, the devices cannot even be switched on.
Devices in the NU series monitor the neutral conductor on the supply side. The DHS 6 NUS extends this function with an additional sensor contact for monitoring the neutral conductor rail, thereby providing increased protection.