But before we look at the supervisor, let's see what happens to our electrical appliances without him and in what cases. And then we will see what it is used for…
Many electrical and electronic components are useful for the protection of our appliances and especially of expensive and those who have electronic parts of appliances eg: Fridge, TV, computer, washing machine, air conditioner and others ...
To say that we will have maximum protection, we also need a lot of money! Nevertheless, we will observe in many cases with every protection measure we use, more and more "strange" current will "slip" and some of our electronic device will take over.
But what happens when our devices are burned or destroyed by electricity?
We will notice that in all the devices their label indicates the ideal operating voltage. And why do we say ideal? Because the trend is almost never constant. That is, we will see it go up and down from… heights to θη depths !! While this device works well at specific volts without voltage fluctuations.
We will notice that all things or living things on earth have the same symptoms! We also hear hypertension and hypotension in medicine !!
And it's exactly the same thing! Man is programmed to work with a pressure of 12/8 when one of these two values exceeds the limits up or down we have a terrible issue. Especially when the pressures are out of bounds for a long time and we do not know it, at some point the stroke comes and the "machine" or the hood gets repaired !! But there are also people who understand it from some symptoms early, when they improve it !!
Let's leave medicine, which is often like electricity, and move on to the subject again πάλι
Ideal trend
All single-phase devices manufactured for our country, for a few years now are manufactured with an ideal operating voltage of 230volt. This is the promising trend provided by HEDNO in phase. What happens now if the trend exceeds this limit upwards or downwards?
Simple, as long as we do the operations with the law of ohms. We will notice as the voltage drops, the amperes increase (so more intensity). What does more intensity mean? It means an increase in temperature and current within the electronic circuits. This is the slow death of our devices !!
If the voltage drops a little or rises a little above the ideal 230V does not mean that the devices are burning. They work on both 210 and 200 and… .190 and …… boils! From 210 to 250 in theory there is no problem. When these values are exceeded the problems begin. We will hear the fridge struggling and little by little the other appliances will burn boards. Air conditioners also pull a lot with the fluctuations….
So a problematic trend will cause us a slow death in the devices. The lower the voltage, the faster the devices will deliver spirit.
If you look at the back of the PPC bill you will see that they OPTIONALLY suggest the use of surge protectors or hypotension. Because PPC does not provide what it promises, again the consumer has to incur costs for its protection.
Does only the problem in the phases cause death in our devices?
No! The most important problem is the interruption of the neutral conductor! It is the worst that can happen in an electrical installation and is a fairly common phenomenon throughout Greece and especially where the TN protection system prevails . So in case of neutral interruption we have an IMMEDIATE death of devices !!
Good then. And what do we do about all this? Is there a solution to protect ourselves?
There are many ways to protect yourself. If we use all the means we need a cart of money, especially if we go to reliable solutions and not to cheap basket accessories.
The main ways are: Lightning protection, Overvoltage protection, voltage stabilizer, UPS, voltage monitor, temperature monitor, arc detector and many more. So you understand that to buy all this, we need a lot of money.
How do we choose a way to protect ourselves from all of the above?
Because I am addressing mainly the ordinary consumer and not an industrial installation (most of them have taken measures there) we must first calculate what devices we have, how much it costs to replace them and from there we choose protection. So, in a simple installation where the ordinary consumer "hurts" is to protect the following: Computer, TV, stereo (if any) refrigerator, air conditioner. These are the main ones. So we need to know that with a big voltage drop these devices are really struggling! But we do not know this or someone experienced will understand, seeing some "signs" in the installation such as the flicker of the lights (if they are led the lights will flash or burn often) noise in the refrigerator or air conditioners and more.
So we calculate what it will cost us the slow death (which applies to all devices) and the instant death that occurs in special cases, but often and especially in unsustainable networks such as islands (eg polar voltage due to return currents in the TN network)
The voltage monitor will show us the problem very soon! What do we mean? That the supervisor, depending on what values we have set, will cut off our electricity supply. Whether these are momentary voltage drops or permanent.
Surveillancers are of different types and have different settings. An ideal and economical monitor that ALWAYS saves us from disasters is the phase voltage and neutral monitor! Attention here, many years now, whoever put a monitor, put a single-phase or three-phase voltage monitor. However, this is not useful in networks mainly TN. Because there we meet more neutral holidays, so we need a supervisor who will monitor neutral !! It is a few euros more expensive but it literally saves our devices.
How is the voltage monitor placed? Is it a difficult process?
It is not at all difficult to place. As long as there is the required space in the table. See drawing below ...
What do we need for the placement of the supervisor?
First of all a phase monitor and neutral. If the installation is three-phase, we want something like this… ..
Automatic fuses from 2 A - 6 A
A three-phase or single-phase power relay (depending on the installation).
It is usually good not to load the monitor directly with the loads and to use it as an auxiliary circuit, so the use of a power relay that will accept all loads is necessary.
Once installed, we start the adjustment. We will see that it has some buttons on it…
In one we state how much voltage drop we want the monitor to stop
In the next, how much voltage excess do we want to stop
In the next, in how much time do we want it to stop !! That is, if the drop or hypertension lasts for a few seconds, we can choose not to stop. And the interruption should be done ONLY when the voltage drop lasts long enough, when it will create a problem.
Disadvantages of voltage monitor
The disadvantages of the voltage monitor are… one! Every time he "sees" a problem, then… .the electricity falls in our house! This is a bit spastic especially when we are lying on the couch and enjoying a movie in our home cinema or we are in a party and suddenly… .darkness !! But if we think about the benefits and that our good 50 '' TV saved it, then we say… let the old vine go!
If we are a little more "comfortable" now we can add a voltage stabilizer to the installation. In this case and with small fluctuations we will notice that the monitor will fall more sparsely!
If we want even more autonomy and not instantaneous interruption, then we can add a UPS that will power our sensitive devices. So eventually (despite the stabilizer) the current may drop, but the UPS will give us the time we need to shut down our devices with complete safety.
We can have socket protectors anyway. These are both economical and do work in both falling trends and momentary surges.
I'm not interested in a housekeeper. Can I ONLY put on my sensitive devices?
Of course we can. We can select the lines that include the sensitive devices and only these can be controlled by the voltage monitor. In any case, the ohmic resistances are not damaged by fluctuations.
But again, especially in 2018, we will notice that even the electric stove now has a cart electronically. Our led bulbs are all electronic and sensitive to fluctuations. Generally be aware that: Any electrical appliance that contains electronics has an issue with voltage fluctuations.
Conclusion: The most important component in an electrical installation after the leakage relay, is the phase monitor and neutral SAVES literally everything in a house - office - building - factory.
VOLTAGE MONITORING CONNECTIONS
PPC writes on the back of each account: Small or large changes in the supply voltage are unavoidable as they may be due to natural phenomena, etc. etc. and continues below: Customers can optionally install appropriate protection devices to prevent damage or the appearance of abnormalities in the operation of their devices. (And of course it's like he says, I warned you not to ask me for the leftovers for the burned TV.)
Voltage fluctuations are a common phenomenon observed in electricity networks. The electrical appliances we have in our house are tolerant of small fluctuations and so no problem is created. However, there are times when the voltage drops to values below 210V or even jumps to 260V and above. The voltage monitor is a useful accessory to protect an installation from dangerous disturbances.
Voltage fluctuations are a common phenomenon observed in electricity networks. The voltage that reaches the electrical panel of our house is constant at 230V. But this only applies theoretically or better "under ideal conditions". In practice, the voltage that ends up in the panel of our house and from there in our appliances takes various values around the nominal, ie 230V. So if we did a voltage measurement at any time of the day, we would most likely get a value like 220V, 225V or 235V. The electrical appliances we have in our home are tolerant of these fluctuations and so no problem is created. But there are times when the voltage sinks in prices below 210V or even jumps to 260V.
Overloading a network, which is usually caused by increased power demand, causes a voltage drop that can reach very low values and last either a few milliseconds (less than a second - 1000 milliseconds = 1 second) or an hour. This voltage drop results in the wear and tear of a home appliance. This way we will see the lighting "flickering" or "weakening" lighting much less than normal, the oven does not reach the right temperatures and in general all electrical appliances do not reach the right performance. If the voltage drop lasts for a few seconds, there is probably no problem at all. But if it lasts for one minute and exceeds it, then the devices that will be used at that time will have a problem. Besides,
However, the opposite also happens. Sometimes due to weather phenomena (lightning) and other times due to the supply from the network we have hypertension, ie the voltage is much higher than the allowable limits. The result of a hypertension is a device "burning". Lightning causes a momentary and abrupt rise in voltage, which in the end may not be "tolerated" by the TV or the computer without of course this being absolute. But if the overvoltage is caused by the network itself and lasts longer, then the chances of losing one or more devices are greatly increased.
The voltage monitor is a rail material like the rest that make up our electrical panel. The phase conductor passes through the monitor before it reaches the power supply of our electrical installation and so it constantly monitors the voltage value. In the monitor settings we select the upper and lower allowable limit as well as the reaction time. Thus, when the voltage takes values outside the set limits, the monitor "counts down" according to the time we have given it (usually a few seconds). If the voltage is still out of range, the monitor "cuts off" the supply of the installation to protect the devices. When the voltage returns to normal then the monitor "opens" the power supply and everything starts working normally again.
I think we are all interested in protecting air conditioners, refrigerators, TVs, computers, etc.
So instead of spending money on a power socket it is better to put a voltage monitor on the electrical panel of the installation and you are done with the problem once and for all, you also protect your Inverter air conditioners that in case of overvoltage there is a serious possibility of their destruction (they have their own security) .
Also to say that the voltage monitor is a good solution for protection against neutral interruption
The voltage monitor is an electronic device that controls the voltage in the electrical network of the system for undervoltage, overvoltage
There are single-phase monitors (phase + neutral) and three-phase monitors (3-phase or 3-phase + neutral).
The monitor has two contacts, a normal open and a normal close, with which we can control the circuit through a power relay.
The monitor monitors the voltage and depending on the overvoltage or undervoltage we have set it to excite or deactivate the power relay.
In this way it stops the operation of the installation in case of voltage error.
In the photo below we see a three-phase voltage monitor and next to a rail load relay
the load relay best installed after the IGC to be secured and that any leakage or short circuit, although I have seen it and put it before the PPC as in the photos above.
Mounted
The monitor is installed after the main switch and the general fuse and before any other material on the panel so that it can have voltage control.
At this point we will remind you that the correct order of placement of the general elements technically and legally according to ELOT HD 384 in the electrical panel of the installation is:
We start from the supply of PPC to the house connected in series
General switch
General Security
Fuse disconnector with melt 1A or automatic fuse 1A
Voltage Monitor Two-
phase indicator with blue and green light
Leakage Relay (DDE)
Load relay (The load relay must have contacts that can withstand the MAX current (A) that can pass through the panel! Eg for 35A fuse = 10mm ^ 2 NYA supply cables we would put 40A load relay).
The load relay is installed after the D.D.E. (although I have seen it before as in the photos below) to secure it for any leakage or short circuit.
To secure the monitor we must use an automatic or fuse 1A fuse.
Voltage monitor design with load relay after PIP
Voltage monitor design with load relay before PIP
When we also have lightning rods, the series is:
General Switch
Fuses Lightning
Lightning Anti- lightning Voltage
monitor Power relay commanded by the supervisor and at the output of the relay we put general fuses and power supply
(This series is according to Hager)
A device I have encountered many times is the following
At this point we should emphasize that the voltage monitors provide us with different functionality and the lightning rods have a different function. I am referring to this issue because there is confusion between the two.
The voltage monitor protects us from permanent hypertension or hypotension.
While lightning rods are devices that protect us from shock voltages and currents. which the supervisor cannot perceive and where he is exposed.
So for a more effective protection device we should install a lightning rod in the electrical panel of our house.
Also the voltage monitor isolates our installation in a voltage error and can not ensure its stabilization. This function is provided by a voltage regulator.
Some examples of voltage monitors
Presentation of the single-phase product
The EU-102 single-phase monitor allows monitoring of the DC or AC voltage connected to terminals 5 and 9.
EU 102 is programmable.
The following parameters can be specified:
λειτουργίας mode of operation (monitoring of overvoltages, undervoltages or both)
● signal type (dc or ac)
,. Voltage and lag limits,
● reaction time t1,
μνή memory function.
EU 102 has LCD display, two setting keys and a function indicator
Technical characteristics
Electrical characteristics
● Power supply: 230 V 50/60 Hz
● Consumption P ≤ 3 VA
Functional characteristics
Τά Voltage limits:
15 V to 700 V DC
15 V to 480 V AC
● Delay:
5 to 50% of the corresponding limit you have set
● Reaction time (t1)
0,1 to 12 s
Ambient conditions
λειτουργίας Operating mode: -20 to 55 ° C
● storage temperature: -40 to +70 oC
connection conductors of
● Stranded as 4 mm2
● single stranded as 6 mm2
Kanoniki mode
In the normal mode the display shows the measured voltage.
If an error occurs and the memory is active, then you must press reset to return the product to normal operation.
The indicator shows the errors:
flashes during reaction time t1 (see Programming) and after this
programming remains on
By pressing the set and select keys simultaneously for 3 sec you enter the
programming mode . The display shows Prog for 1 sec.
Set key: to validate a selection Select
key: to scroll between parameters or their values.
The programming steps are as follows:
σή Select signal type: AC or DC
➁ Surveillance type selection:
overvoltage (Up)
undervoltage (Lo)
overvoltage and undervoltage (Up Lo)
➂ Select voltage limits:
If you have selected Up monitoring then you need to adjust the upper limit
If you have selected Lo monitoring then you must set the lower limit
If you have selected Up Lo monitoring then you must set both limits
θο Determine the Hys (Volt) lag.
If e.g. if you have set the upper limit to 250 V and some overvoltage occurs, then in order for the monitor to reactivate your circuit, the voltage must fall below 250 - Hys V. If you set, say Hys = 20 V, then the circuit will only be reactivated if the voltage drops below 250 - 20 = 230 V.
If you have selected Up Lo monitoring then you do not need to set a lag.
. Determination of reaction time t1 (in sec).
If the monitored voltage exceeds the limits you have set, then the monitor will interrupt the control circuit at time t1. If the overvoltage / hypotension lasts less than t1 then the monitor will not react
➅ Memory mode selection:
memory active: yes M
in this case the monitor does not automatically reset the monitored circuit. You must press reset to restore
inactive memory: no M
in this case the monitor always resets the monitored circuit automatically.
Τισμού End of planning.
To validate the entire program, press set. If you press select then you return to steps 1 to 6
Hager EU302 Three Phase Voltage Monitor
Here I would like to show the Hager EU302 voltage monitor. The reason I focus on this is because it contains difficult blueprints. (from http://fubar.gr )
For this reason, I will try to decrypt the user manual, so that it is more understandable for anyone wishing to install the same monitor model.
The user manual can be downloaded here: Hager EU302
So let's start decryption. The first blueprint is quite understandable:
Shows how it is connected in the three phases (parallel to the phase lines, in terminals 1, 5 and 9 respectively) and the minimum and maximum cross sections of the conductors, depending on whether a multi-strand or single-strand cable is used. Terminals 2, 4 and 6 are relay contacts, with 6 being common, 4 being Normally Closed and 2 being Normally Open.
It also has an on-off switch, without any description on it and two sliders, one for the time (with a range of 0.1 to 12 seconds) and one for the level at a rate of one hundred, from 5% to 20%. One would expect them to have written a slightly more detailed description on the front of what exactly this percentage and time means, so that the electrician can understand at a glance, without looking at the user manual. And as we will see later, it is not so obvious what exactly these sliders do.
To the left of the above layout, is the following table, which does not have a title or description.
These as I understand it are the so-called Absolute Maximum Ratings, ie the values of voltage, current, temperature, etc. which in no case and for any period of time should not be exceeded, otherwise permanent damage can be caused to the device.
What confuses is Ik. At first I thought it was a current, but it does not have any intensity unit after the number 3. So I think it means IK rating, or impact protection rating, which roughly represents the device's resistance to shocks. Whether it is a uppercase or lowercase letter is very important in technical manuals because it can mean something completely different.
At the bottom half of the page we see the following diagram, which fully describes the operation of the supervisor, in the most difficult way that would ever be possible!
Let's look at the top section first:
This at first glance looks like a very irregular sinusoidal voltage waveform. But it is not the halftone of the "real" AC voltage, but its RMS value, and we understand this from the vertical axis, which starts from zero.
If it were a representation of the sine wave of the trend, then it should also take negative values and be symmetrical about the horizontal axis.
In other words, this chart shows a trend that is fluctuating. On the left it shows voltage dips, while on the right it shows surges. If the voltage was normal and completely constant, then it would be shown with the red line in the diagram below as Un, ie nominal voltage. In the user manual of the similar model Hager EU301in the corresponding diagram the nominal voltage Un
The chart has four different trend levels marked. Let's take the right part with the surges first. The upper voltage is marked as Up = 1.15 Un. The voltage Un is the rated voltage (nominal voltage) and has been defined based on the document CENELEC HD 472 S1 throughout the European Union as 230 Volt RMS + -10%. That is, the normal range can be from 207 to 253 Volt RMS.
So the Up voltage in the diagram is defined as 1.15 Un or 15% above the nominal, or 264.5 Volt RMS, assuming that the Un voltage is exactly 230 Volts.
Immediately below the Up voltage, we have the Up voltage - 1% Up. This if we calculate it comes out 261.85 Volt RMS.
Now let's go to the left part of the hypothesis chart. The lowest marked voltage is Lo = Un-Δu.
What Du is mentioned below:
Therefore Δu is regulated by the slider with the inscription level (%) and is the percentage on the nominal voltage Un.
Suppose we choose the minimum percentage, ie 5%. Then Δu = 5% Un = 11.5 Volt RMS.
Therefore, the voltage Lo becomes: Lo = 230-11.5 = 218.5 Volt RMS
Therefore the immediately marked voltage Lo + 1% Lo is equal to 220.69 Volt RMS
Let us now see what is the significance of these levels voltage and how the supervisor reacts accordingly.
In the blueprint I have noted the trends we calculated previously and I have numbered the interesting time points on the horizontal axis. Let me remind you that in the example we consider Un = 230V and Level = 5%, otherwise, these voltages will come out different.
This diagram shows us when the relay contact is turned on and off (which we usually use to arm another power relay - relay), and when the Def light comes on while the Memo switch is OFF.
Thus we see that starting from the time point zero the voltage starts and gradually increases until it peaks at the Un voltage. At this stage the supervisor does not detect any error, so I guess he has a short "grace period" at the start until the trends stabilize.
Then, from the Un value, the trend starts and falls. It drops below 220.69 V but nothing happens, except when at point 1 the voltage drops below 218.5 Volts. From there, we see that the Def light flashes for a period of time t (which we set with the slider on the front of the device) and when this time has elapsed, the relay contact is activated (and therefore with the standard connection method will the supply of the installation is interrupted).
Then the voltage gradually returns, rises above the point of 218.5 Volts, but nothing is done until the voltage rises above 220.69 Volts at time point 2, at which time the relay contact is deactivated (and consequently the power supply is restored to the installation).
So here we see that there are two levels of voltage. The supply is interrupted when the voltage drops below the low level of 218.5 Volts, but returns when it rises above the high level of 220.69 Volts.
This is called lag and we also use it in electronics, when for example we make a voltage comparator with op-amp. If we had only one voltage level, then the slightest micro-changes of voltage close to this level would cause the monitor to open and close its contact very quickly and consequently to interrupt and resume the supply quickly, which it would do. greater damage to the installation. The lag gives greater stability to the system. This function is also called Schmitt Trigger.
And the exact same function exists in the case of surges. That is, the supply is interrupted only when the high point of 264.5 Volts is exceeded, and returns when it falls below the low point of 261.85 Volts.
The other feature that we observe from the diagram is that if the hypertension-hypotension lasts for a period of time shorter than what we have chosen, then the supply is not interrupted (time points 3-4 and 9-10).
If again the voltage is completely zero, ie phase loss (time point 6) then the monitor goes off and stops working.
Here is an important remark! The monitor relay contacts do not actually work as shown in the diagram!
The diagram implies that normally the relay coil is switched off and contact 6 is connected to contact 4, and when overvoltage or undervoltage is detected, then the relay is activated and contact 6 is connected to contact 2.
But in fact when the monitor detects normal voltage, then it activates its relay and the contact 6 is connected to the contact 2. When it detects overvoltage or undervoltage then the relay is deactivated and the contact 6 is connected to the contact 4.
Therefore, the relay must be supplied between the contacts 6 and 2, and not 6 and 4.
It could not be otherwise its operation, because if it was done as in the plan, then in case of loss of one phase, it would continue to provide the installation the other two, effectively canceling one of the main reasons we put a supervisor in an installation !!!
As for the Memo switch, when it is on it means that the supply will not return automatically after overvoltage-undervoltage, but we will have to lower and re-raise the switch manually to return.
Therefore summarizing:
In this model Hager EU302 voltage monitor:
We can adjust the voltage level, from 5% to 20% below the rated voltage
The voltage level is fixed at 15% above the rated voltage
We can adjust the time interval from the detection of hypertension-hypotension to the interruption of the supply from 0.1 to 12 seconds.
If the overvoltage lasts less than the predetermined time then the supply is not interrupted.
The supply is restored immediately when the voltage returns 1% above the lower voltage point or 1% below the maximum overvoltage point. There is no option to delay the reset, as other monitors have.
If the Memo switch is ON then even if the voltages return to normal, the supply will remain off.
It does not appear anywhere that this monitor can detect phase asymmetries or phase successions. Therefore, if we want asymmetry and succession control in the installation, then we should choose another monitor model, or combine it with an asymmetry and succession monitor, such as the Hager EU300.
It is not specified whether Un voltage is considered stable at 230 Volts or whether there is a "learning" period during which it adapts to the local voltage of the installation. My personal opinion is that the latter happens, as otherwise there would be other models of hypertension-hypotension monitors in the Hager range, but this is the only one.
Therefore, the conclusion is that this monitor is suitable for three-phase installations in which the loads are single-phase, ie there are no three-phase motors or transformers, where in such a case we want the monitor to check for both asymmetry and phase succession.
To thank the ELECTRICIANS of the 1st EPAS OAED THESSALONIKI for the amazing technological content and the wonderful articles they publish on their blog.
