Every electrical specialist who sees himself as a competent electrical specialist can and knows them; the five safety rules defined in the VDE 0105 part 100:

• First: Disconnect from the mains
• Second: Secure against reconnection
• Thirdly: Verify that the system is dead
• Fourth: Carry out earthing and short circuiting
• Fifth: Provide protection from adjacent live parts

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Before working on a system or equipment, it must be de-energized. Disconnect all live parts or connections from the system or the part of the system on which work is to be performed. This may involve, for example, the three phases of a system. However, it is not sufficient to merely switch off the light via a toggle switch as is the case with the kitchen light switch.

Secure against restarting

It is not enough to de-energize the system, it must also be ensured that no one is able to re-energize the system. There are different locking devices for this purpose. Signs with notices such as “Do not switch” will also be posted. However, this sign alone does not replace the actual securing against being switched on again, for example with a padlock that can be locked. My recommendation here is that, if possible, each electrical specialist should have their own lock. After all, as an expert electrical specialist, you should also hold the key to your own safety.

Determine freedom from voltage

After you have enabled the system and secured it against being switched on again, you must determine whether the system or the part of the system on which you want to work is really free of voltage. This is carried out at low voltages, i.e. at voltages below 1000 volts AC and 1500 volts DC, by a qualified electrical specialist using a two-pole voltage tester in accordance with IEC EN 61243-3. Not with a multimeter! A multimeter with integrated voltmeter is a measuring device and not a testing device. For example, it allows operator or adjustment errors. The two-pole voltage tester must be checked for functionality directly before use. Non-contact voltage testers are not permitted for determining the absence of voltage. The rule is explicitly called “Determine absence of voltage” to make it clear that the rule has only been carried out correctly and work may only continue when it has been determined that there is no longer any voltage on all poles.

Grounding and shorting

To start with a clarification right away; it is NOT called “shorting and grounding“, but quite deliberately “grounding and shorting“. Thus, after establishing the absence of voltage, the grounding system is connected to all conductors short-circuit proof. The order is relevant to safety. In general, grounding and short-circuiting is only required for medium voltage and above and may be omitted for low voltage as long as the first three rules have been properly implemented, however, there are also sufficient situations in the low voltage range where grounding and short-circuiting is useful.

Cover or fence off adjacent live parts

If there are live parts in the immediate vicinity of the system or system part which are not completely safe to touch and cannot be switched off, they must be covered with adequate means such as special insulating mats so that they are protected against electric shock even in the event of accidental contact. If this is not possible, they must at least be barriered off to the extent that accidental contact is impossible as long as you are on the safe side of the barrier.

As a knowledgeable electrical specialist, keep your senses alert to all hazards and always work safely according to the five safety rules.

Our free(REALLY free, even WITHOUT having to provide an email address!) paper “5 Things You Must Have Clarity About Before Qualifying and Deploying Your Employees for Electrical Engineering Work.” can be accessed here (click).

If you would like to know more about the different roles, in particular those of the EiP, ES, CRES and especially those of the CRES and how they interact, I recommend our publications, for example the audio book “Die Verantwortliche Elektrofachkraft: CRES-Struktur und Betriebliche Elektrosicherheit für Unternehmer, Fach- und Führungskräfte”. Information and sources of supply can be found on the usual audio book portals as well as on the homepage tcs-engineering.de

Among experts, one often hears the not uncontroversial representation that every specialist high voltage (ev) is an electrical specialist in the sense of the new DGUV Information 209-093, since the corresponding high voltage training would make him one. The new DGUV I 209-093 “Qualification for work on vehicles with high-voltage systems” as the successor to DGUV I 200-005, which is valid until 2021, is still causing some discussion among experts, and not only among experts for high-voltage training or high-voltage qualification. Thus, the statement “Every newly qualified SHV (specialist high voltage) is an electrical specialist” is popular. And this is not fundamentally wrong either. This statement is based on the last sentence of the note to the foreword of DGUV I 209-093, which reads: “The “High-voltage specialist” (SHV) described below is an “electrical specialist” in accordance with DGUV regulations 3 and 4 for the electrotechnical subarea of high-voltage systems”.

So is this the final answer to the question? The answer is a resounding “no”! First of all, a short excursion into other regulations and standards. According to Section 2 (3) of DGUV Regulation 3, an electrical specialist is “someone who, on the basis of his technical training, knowledge and experience as well as knowledge of the relevant regulations, is able to assess the work assigned to him and recognize possible hazards.” Similar formulations can be found in VDE 1000-10, VDE 0105-100 or EN 50110. This definition, which is binding in the formulation of DGUV Regulation 3, also extends in principle to the classic electrical specialists for defined tasks (EFKffTs) according to DGUV Principle 303-001, which was described in this blog post (LINK). Thus, the ESfdt is also an electrical specialist, but one for defined tasks. The legal basis for this is provided by § 7 ArbschG (“Transfer of tasks”) in conjunction with §§ 7 (“Qualification for activities”) and 21 (“General obligations of the employer”) of DGUV Regulation 1 (“Principles of prevention”) as well as the guarantor position incumbent on the responsible persons.

In particular, Section 7 of the ArbschG obligates the employer to pay attention to the professional suitability of its employees. It could therefore be argued that it is at least not impossible and in itself possible to employ any SHV as an electrical specialist, provided that the employer can be shown to be able to trust this SHV with the assigned tasks, particularly from the aspect of hazard prevention and safety.

Due to the requirements of the relevant regulations, the restriction to the specified activities should by no means be disregarded when considering the SHV in accordance with DGUV I 209-093! Although DGIV I 209-093 no longer makes a titular distinction between the SHV and the HV (ev), it does clarify in several places itself the safety-related gradation of entrances A through D of the SHV qualification to Level 2E. This is particularly clear in Chapter 4.1.5 DGUV I 209-093; here, it is even literally described that employees without adequate training must have their electrotechnical knowledge and skills checked despite being qualified to Level 2E. Although this refers specifically to level E3, i.e. live line work, it nevertheless illustrates the clearly different evaluative standpoint and thus use.

Therefore, one should not take the supposed equality mentioned only in the preface too lightly and always consider the principles of electrotechnical safety, to whom which tasks are handed over. Finally, it is and remains the responsibility of the CRES or the entrepreneur who receives which task and competences. This should not be tied to high-voltage training alone. Every employee is much more than just the sum of his or her training and qualifications; this also applies to (ev) high voltage.

PS: Our recommendation here: There are also courses offered by various providers, such as the aforementioned course “Specialist high voltage (ev)” or also the small course for the specialist instructed person for high voltage. More information about this can be found on our homepage
www.tcs-engineering.de
We offer various open seminars as well as customer-specific in-house seminars.

Our free(REALLY free, even WITHOUT having to provide an email address!) paper “6 Things You Need to Know About High-Voltage Qualification of Your Employees in Advance” can be accessed here (click) .

If you want to know more about the different roles, especially those of the responsibilities and especially those of the CRES and their interaction, I recommend our publications, for example the audio book “The chief responsible electrical specialist: CRES structure and operational electrical safety for entrepreneurs, specialists and managers”. Information and sources of supply can be found on the usual audio book portals as well as on the homepage tcs-engineering.de

(ev) high voltage training – specialist for high voltage systems vs. electrical specialist for defined tasks

Whether in (ev) high voltage technology or in plant engineering, abbreviations are used a lot. The EiP, the ES, the ESfdt, the FfHV, LLW and so on.

The ESfdt is a particularly exciting abbreviation, the pronunciation of which is already half a tongue twister; the electrical specialist for defined tasks. We recently published an article on the ESfdt(link article “The electrical specialist for defined tasks”). In it, the FfHV was only briefly mentioned, so it was not about high-voltage topics or high-voltage training or high-voltage qualification but about the definition in general electrical engineering.

The FfHV – the specialist for high-voltage systems – is an ESfdt for the high-voltage sector. The FfHV may perform electrical work on high-voltage systems, including HV (ev) disconnection and HV (ev) commissioning, after successfully completing high-voltage training and being appointed by the employer in accordance with work instructions. However, only according to work instructions, i.e. checklist.

Of course, the “specialist for high-voltage systems” could also have been called “electrical specialist for defined tasks – high voltage”. Personally, I am quite happy that they found another abbreviation, “EFKffTHV” sounds a bit exaggerated.

However, the distinction can also lead to confusion.

There is also an ESfdt for different areas, but in the high-voltage area it is the FfHV – every person who has to do with HV vehicles or batteries needs a high-voltage training for the FfHV for certain work.. But FfHV also shows that specialization is becoming increasingly important. In vehicle technology, for example, the passenger car sector is similar to but already different from the VAN sector. When it comes to electromobility for buses and trucks, completely different factors are important. Similarly, it makes a difference whether someone is working on complete high-voltage systems such as finished vehicles or on individual vehicle components – especially in the area of battery production and development. Battery production in particular requires adapted high-voltage training for the respective employees. Depending on the size, it may be worthwhile to set up your own training concept or have it set up so that the high-voltage training is adapted to the requirements and conditions.

Our trainers must know the difference inside out; after all, some are involved in training courses for electrical specialists for defined tasks (ESfdt) as well as in high-voltage training courses for specialists for high-voltage systems (FfHV) on vehicles as well as in battery technology.

Note: The regulation on the specialist for high voltage systems according to DGUV I 200-005, which was valid until 2021, has now been replaced by the specialist high voltage (ev) according to the new DGUV I 209-093, but the old certifications remain valid.

For more on current qualifications, our free(REALLY free, even WITHOUT having to provide an email address!) paper “6 Things You Need to Know About High-Voltage Qualification for Your Employees in Advance” is available here (click) .

Equipotential bonding in the (ev) high voltage system:
A central element of high-voltage safety

In any (ev ) high voltage training course, measuring equipotential bonding is a key exercise. Equipotential bonding within an HV (ev) component as well as equipotential bonding between any two high-voltage components in an electric vehicle. Specifically, between the housings, as the bodies of the respective high-voltage components. The potential equalization resistance is determined with a so-called milliohmmeter. Good milliohmmeters work on the basis of the so-called four-wire measurement. (This is not to be confused with the three-wire measurement, which is mostly used for measuring ground resistances).

Every electrical specialist (ES) as well as specialist for high voltage systems (FfHV)/specialist high voltage (SHV) is therefore used to handling the milliohmmeter. According to section 5.1 of UN ECE R 100, “the equipotential bonding resistance between any two exposed conductive parts must be less than 0.1 ohms.” This is thus a rather strict regulation, the meaning of which will be briefly explained here.

The high-voltage network is an IT-like network; accordingly, both HV+ and HV- are galvanically isolated from the vehicle ground and all equipment bodies.

If a short circuit should occur in a high-voltage component (regardless of whether HV+ or HV-), there would initially be no danger, since no electrical circuit is closed due to the galvanic isolation. This alone provides a certain level of security. However, high-voltage safety is characterized by the particularly high level even in the unlikely worst case.

If a second body short circuit of the other pole should occur at a different location, the short circuit current must be able to flow stably via the equipotential bonding so that the HV (ev) fuse within the high-voltage battery can trip safely.

Example: There is a body short circuit of HV+ within the power electronics and later a body short circuit of HV- at the high-voltage battery itself.

Since both vehicle ground, high-voltage battery body and power electronics are conductively connected to each other via the equipotential bonding, a short-circuit current will flow via the equipotential bonding and can trigger the HV fuse of the battery. The equipotential bonding must therefore also be able to withstand corresponding loads, which is an important factor in addition to the pure resistance value.

However, the equipotential bonding has another function; it enables the insulation monitor to detect an HV (ev) fault at any point on the vehicle. Since insulation monitoring is only performed at one point on the vehicle, a fault against any component can be detected thanks to equipotential bonding. This means that errors are detected at an early stage and can be corrected long before a worst-case scenario can occur. There will certainly be a separate article on the subject of insulation measurement.

Equipotential bonding thus fulfills central safety tasks in the (ev) high voltage vehicle, which is why it is so important in high voltage training courses.

PS: Our recommendation here: There are also courses offered by various providers, such as the aforementioned course “Specialist high voltage (ev)” or also the small course for the specialist instructed person for high voltage. More information about this can be found on our homepage
www.tcs-engineering.de
We offer various open seminars as well as customer-specific in-house seminars. Of course, the measurement of equipotential bonding is one of the standard exercises of the SHV qualification: everyone measures the equipotential bonding resistance. :-)

Our free(REALLY free, even WITHOUT having to provide an email address!) paper “6 Things You Need to Know About High-Voltage Qualification of Your Employees in Advance” can be accessed here (click) .

Is high voltage not the same as high voltage – difference between high voltage and (ev) high voltage?

More and more often, even as a lay person, you hear the term “(ev) high voltage”. As an expert in (ev) high voltage technology, I am therefore frequently asked, especially by people I know, “You do all these (ev) high voltage training courses, wasn’t that once called high voltage”.

The short answer would then always be simply a clear “No”.

However, since I am very aware that the statement “(ev) high voltage and high voltage are not the same thing.” seems only conditionally satisfactory, I am happy to answer in detail, which led to this blog entry.

In order not to get too much into boring lecturing, I will try to start with the simple differences.

(ev) high voltage and high voltage are not only two different voltage levels, but also found in different areas.

High voltage is a term from classical electrical engineering as we find it in the VDE since time immemorial.

There are the terms of low voltage (usually touching up to 50 V AC and 120 V DC), low voltage (up to 1000 V AC and 1500 V DC), medium voltage (up to approx. 50 kV), high voltage (mostly 110 kV) and extra high voltage (220 kV, 380 kV and 400 kV).

(ev) high voltage, on the other hand, is a term from automotive engineering and describes the voltage range for alternating quantities (AC) greater than 30 V and up to 1000 V, and for direct quantities (DC) greater than 60 V and up to 1500 V.

(ev) high voltage is therefore by and large fully in the low-voltage range.

Now low voltage also sounds much more harmless than it is. Low voltage can kill you, everything we find in private homes and offices as well as workshops belongs to low voltage. The term “Low Voltage Directive” as one of the most important directives not only for the safety of man and machine is often not unknown to the lay person.

High voltage, at about 110 kV (i.e., 110,000 volts), is well over a hundred times higher than the high-voltage range.

(ev) high voltage thus explicitly describes the voltage range of electric vehicle drives. This voltage range also requires special safety measures, both technical and organizational or personnel. In terms of personnel, we implement this in our high-voltage training courses, such as the training for specialists in high-voltage systems in vehicle technology, specialists in high-voltage systems in battery technology, and also the electrician training courses for high-voltage systems, live line work in high-voltage battery technology, and so on.

The term (ev) high voltage clearly illustrates the necessary caution in handling high-voltage vehicles, especially in the automotive sector. In our experience, the term low voltage would make most vehicle engineers think of the on-board power supply – 12 V, 24 V or at best 48 V.

but a typical voltage of a high-voltage battery is, for example, 400 V or 800 V.

And there is real power behind it. High-voltage training for employees is therefore not only sensible, but also mandatory, depending on the activity.

So, please remember even without high voltage training: (ev) high voltage and high voltage are two different things – but they are both potentially dangerous.

PS: Our recommendation here: There are also courses offered by various providers, such as the aforementioned course “Specialist high voltage (ev)” or also the small course for the specialist instructed person for high voltage. More information about this can be found on our homepage
www.tcs-engineering.de
We offer various open seminars as well as customer-specific in-house seminars.

Our free(REALLY free, even WITHOUT having to provide an email address!) paper “6 Things You Need to Know About High-Voltage Qualification of Your Employees in Advance” can be accessed here (click) .

If you want to know more about the different roles, especially those of the responsibilities and especially those of the CRES and their interaction, I recommend our publications, for example the audio book “The chief responsible electrical specialist: CRES structure and operational electrical safety for entrepreneurs, specialists and managers”. Information and sources of supply can be found on the usual audio book portals as well as on the homepage tcs-engineering.de

The electrotechnically instructed person

According to Section 3 (1) of DGUV Regulation 3, all electrical work must be performed by an electrical specialist or under the direction and supervision of an electrical specialist. Thus, even the electrotechnical lay person is allowed to participate in, for example, the installation of electrical systems. However, the use of electrotechnical lay persons is severely limited. This is why there is the electrotechnically instructed person, or EiP for short. As a reminder, the electrical specialist had to be qualified to the extent that theycould “evaluate the work assigned to themand identify potential hazards.”

In the case of the EiP, successful qualification is assumed if he or she has been sufficiently instructed, briefed and, if necessary, trained on the tasks assigned to him or her in general as well as in detail and on the possible hazards in the event of improper action as well as on the necessary protective equipment and protective measures. Seminars for electrotechnically instructed persons are usually offered for one or two days. This involves the basic terminology and potential hazards of electrical engineering. The central point in the use of EiPs is that the respective electrotechnically instructed person may only work under the instruction and supervision of an electrical specialist. The EiP may neither disconnect nor commission systems or equipment. The results of the EiP’s work are to be reviewed by the ES, as the ES is responsible for them.

You can have an EiP wire an entire system according to a circuit diagram if you, as the ES responsible for the work, trust him to do so. However, the system must have been released beforehand and the work of the EiP must be checked and approved by the ES before commissioning.

If you send employees to EiP training courses, however, the certificate does not automatically qualify them as electrotechnically instructed persons.

As always in the selection of employees, your assessment of the assigned tasks will determine who you appoint as EiP in which area. If you want to qualify several employees as EiPs, it may be worth considering an in-house seminar. If you seek external support for this, talk to the qualifier beforehand about the area for which the EiPs are to be used in order to integrate this as extensively as possible already in the training.

For example, the use of EiPs for equipment testing in accordance with § 5 DGUV Regulation 3 is very popular. Please note, however, that you may only work under the direction and supervision of an electrical specialist.

More information on the electrotechnically instructed person and your role in electrical safety can also be found in our new audio book “Die Verantwortliche Elektrofachkraft – CRES-Struktur und betriebliche Elektrosicherheit für Unternehmer, Fach- und Führungskräfte” (Link: https://www.tcs-engineering.de/verantwortliche-elektrofachkraft-schulung/#hoerbuch )

The electrical specialist for defined tasks – or ESfdt for short – is a highly restricted form of electrical specialist. In principle, the ESfdt is regarded in the same way as an electrical specialist within their area of responsibility, but with very clear boundaries. The ESfdt is allowed to work independently. It may carry out electrotechnical work on its own responsibility, including the disconnection and commissioning of electrotechnical systems or equipment, without an ES having to take over management and supervision. This means that the electrical specialist for defined tasks is considered to be an electrical specialist in the sense of DGUV Regulation 3, but with the addition “for defined tasks“, i.e. only for the work for which he has a work instruction and for which he has been instructed. Without work instructions, an electrical specialist for defined tasks may only be used as an electrotechnically instructed person. A NOT provided, i.e. free troubleshooting, may only be carried out by an electrical specialist.

The training criteria for an electrical specialist for defined tasks are specified in DGUV Principle 303-001. The special background here is that a company can also have employees without electrical engineering training and without years of experience qualified as ESfdts. Depending on the initial qualification and subject area, such a qualification measure lasts, for example, two weeks for theory and practice. However, it is recommended to let an ESfdt work like an electrotechnically instructed person under the direction and supervision of an ESfdt after he/she has been qualified, both to give him/her the opportunity for supervised familiarization and to wait for an assessment by the ESfdt as to whether the latter really considers the employee in question to be suitable for use as an electrical specialist for defined tasks. If there are specialized ESfdt courses, you should also prefer them over general ones. In the high-voltage area of electromobility, this is even mandatory; there, they are called either specialists for high-voltage systems, as defined in DGUV Information 200-005, or, since 2021, specialists for high voltage (ev) according to DGUV I 209-093.

Our free(REALLY free, even WITHOUT having to provide an email address!) paper “5 Things You Must Have Clarity About Before Qualifying and Deploying Your Employees for Electrical Engineering Work.” can be accessed here (click).

If you would like to know more about the different roles, in particular those of the EiP, ES, CRES and especially those of the CRES and how they interact, I recommend our publications, for example the audio book “Die Verantwortliche Elektrofachkraft: CRES-Struktur und Betriebliche Elektrosicherheit für Unternehmer, Fach- und Führungskräfte”. Information and sources of supply can be found on the usual audio book portals as well as on the homepage tcs-engineering.de

Battery safety: Safe handling of the battery in the electric vehicle

(ev) high voltage electric vehicles are showing increasing battery range and their number on the road is increasing. Since electric cars are equipped with (ev) high voltage batteries, battery safety is an important issue. For example, rescue workers must keep self-protection in mind when rescuing people from electric cars involved in accidents. But companies involved in the maintenance and repair of electric vehicles also need to prepare their skilled personnel for the upheaval in the automotive industry with (ev ) high voltage training.

Recognizing and handling (ev) high voltage batteries at the scene of an accident

First responders and accident victims will come into contact with electric vehicles more and more often – sometimes without realizing at first glance that it is a high-voltage vehicle. It is important to clearly identify electric vehicles with traction batteries. Externally, (ev) high voltage batteries can be identified by the orange insulation of their leads and warning labels. For improved safety, high-voltage batteries are subjected to a leak test in production after sealing.

The best protection: intrinsic safety plus (ev) high voltage competence

Electric vehicles have a high level of battery safety ex works. For example, the materials for cathodes, anodes, electrolytes and separators in electric car batteries are designed for effective overcharge protection and flame retardancy. In addition, the (ev) high voltage battery is housed in a separate mechanical and thermal enclosure. In the event of an accident with airbag deployment, the battery contactors open automatically, interrupting the flow of current to the outside. The basic intrinsic safety of the (ev) high voltage battery provides very good protection for the end user as well as workshop employees. A high-voltage qualification such as a high-voltage sensitization in accordance with DGUV I 200-005 Level 1 makes a significant contribution to the safe handling of the battery in the electric car.

(ev) high voltage batteries penetrate everyday life

Electric cars are already part of everyday life for towing companies, car washes and car recyclers. But authorities such as police and customs also come into contact with (ev) high voltage batteries in electric and hybrid cars. These groups of people should know where the energy storage device is located in a model and how to read the rescue data sheet. Batteries from crashed electric cars should be stored at ground level in a well-ventilated area clearly marked with a warning label. Damaged (ev) high voltage batteries can re-ignite even after hours, therefore appropriate fire protection measures must be taken in the storage area. The greater the battery range, the greater the energy content of a battery and thus the greater the importance of battery safety. This is the reason why in production and handling such an immense part of the manufacturer’s effort falls on the point of electrical safety.

PS: Our recommendation here: There are also courses offered by various providers, such as the aforementioned course “Specialist high voltage (ev)” or also the small course for the specialist instructed person for high voltage. More information about this can be found on our homepage
www.tcs-engineering.de
We offer various open seminars as well as customer-specific in-house seminars.

Our free(REALLY free, even WITHOUT having to provide an email address!) paper “6 Things You Need to Know About High-Voltage Qualification of Your Employees in Advance” can be accessed here (click) .

If you want to know more about the different roles, especially those of the responsibilities and especially those of the CRES and their interaction, I recommend our publications, for example the audio book “The chief responsible electrical specialist: CRES structure and operational electrical safety for entrepreneurs, specialists and managers”. Information and sources of supply can be found on the usual audio book portals as well as on the homepage tcs-engineering.de