Questions tagged [surge-protection]

Questions about protecting electrical devices from voltage spikes.

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1answer
47 views

3 phase Load Reactor on a split phase battery inverter, can neutral be on the center phase? [closed]

I intend to use a 3 phase load reactor on the output of a split phase battery inverter to help with surge loads and true power factor, can I wire it with neutral on the center phase of the 3 phase ...
7
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4answers
2k views

Can lightning strike into the phone line damage electronics in the house through the ADSL modem?

I was always wondering about the following: If lightning strikes directly into the phone line outdoors, can the excess power coming from the phone line jump over the switching power supply of the ADSL ...
3
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1answer
66 views

Protecting circuit input against lightning - how to put all the pieces together?

I am designing a single wire (ground return) telephone for use in our hobby caving expeditions, starting out from a well known and successful design called Michiephone (http://speleonics.com.au/...
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1answer
50 views

Difference between placing unidirectional TVS diode before fuse or after P mosfet

In the buck-boost converter I am finishing, I came out with this question. At Vin (12V in my circuit) I place a 7A fuse and a P mosfet (IRF5305) to prevent reverse polarity issues. Because I want to ...
0
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1answer
31 views

Are TVS diodes necessary if device is not grounded? (i.e. portable)

If I'm working on a battery powered device that has no connection to ground, is it still necessary to guard against voltage spikes?
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0answers
42 views

What is the RMS current going through this fuse?

I'm chose a fuse to for a transformer, and now I'm trying to calculate the cross section of the cables. I'm using the following formula: Where Tk is the protection time, Ik the short-circuit current ...
0
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0answers
19 views

lt4363 - 2 Surge Stopper: Shutdown / MOSFET Gate and Vout

Good day everyone I am currently working on the board which uses a Surge Stopper LT4363-2. Without LOAD the circuit works fine but once I use LOAD and force a SHDN to low with a Temperature sensor The ...
2
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1answer
32 views

Relays for switching circuilation pumps

I have a board populated with Omron relays (G5Q-1A4-EU DC5) and I want to use them to switch circulation pumps (https://imp-pumps.com/pumps/ghn/). Is the previous relay appropriate to be used with ...
0
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1answer
47 views

TVS diode for RS485

I'm studying the ISO1500 for an RS485 application. In particular, I'm looking for a TVS diode for bus protection. I've found that a common TVS diode used for RS-485 applications is the SM712 (like ...
0
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1answer
60 views

Surge protector for car USB port

OK so the car manual says not to stick items into the car's USB port while starting the car. Like any good engineer(ing student) I tried to see what will happen if I did so, and am now the proud owner ...
0
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1answer
29 views

Power interference when turning on speakers, causing monitor to go black

I have a small 2.1 external speaker system that I use with my laptop. I also have an external monitor that I use with the same laptop. Almost every time I turn on or off the speakers, the external ...
1
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1answer
58 views

Need help understanding the mosfet trailing edge Dimming

I am working on a circuit to control AC loads up-to 1.5KW by using Mosfets(FCHD125N65S3R0-F155) Circuit is I have few concerns The current is flowing through the body diode of Q2 for positive half ...
0
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2answers
44 views

How is this PMOS FET working as ESD protection?

Can somebody please explain the circuit functionality? I'm thinking of PMOS (\$V_{sg}=0\$) as a current-limiting diode. Am I right?
0
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2answers
47 views

Should I be worried about a surge protector near my pillow

I have just realized how close my surge protector appears to be to my pillow. It is about 20-30cm away. Should I be worried about any EMF/radiation/something else? The surge protector itself is new ...
2
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1answer
95 views

Power line surge on the Active and Neutral line

Since a while, I've been having massive powerline spikes on both the Active and Neutral line. It happens when I turn on a light (with a trafo attached to it), or have an ESD with my floormat, or when ...
10
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4answers
83 views

Why are modern telephone lightning arrestors less prone to (rectification) RFI problems than old ones?

I was reading about telephone lightning arrestors in my ARRL RFI Book (first edition, copyright 1998), in chapter 9 "Telephone RFI" (by Pete Krieger, previously WA8KZH, now K8COM) and on page 9.6, the ...
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2answers
40 views

Position of lighting current arrestor

Can i put lighting current arrestor before F1 in main distribution board?
1
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0answers
34 views

lightning protection on LAN cables indirect strike crowbar VS isolation

i am using a crowbar lightning protection system we built 10 years back for LAN on our own devices for the mine industry. it works very well. at that time i decided to use TVS bidirectional 18v , GDS ...
-3
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1answer
61 views

surge voltage characteristics of ceramic capacitors

I am reading a datasheet from Murata for a ceramic capacitor. According to the datasheet: When AC voltage or pulse voltage is applied, the peak-to-peak voltage shall not exceed the rated DC ...
0
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2answers
48 views

Can a Surge Travel on a Residential House's Wiring that is higher than 6kV and 3kA?

IEEE has stated that the highest voltage and amperage that a surge can travel on home wiring is 6kV and 3kA. Anything higher, the wiring would melt. If this is so, how does a surge from direct or ...
1
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0answers
61 views

Why is the maximum voltage of a surge, 6kV inside home wiring?

I was reading about the benefits and cons of series mode surge protectors vs MOV-based surge protectors for home use. First, why is the probability that a surge will exceed 6kV extremely low due to a ...
0
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2answers
85 views

Varistor - Place before or after the fuse? [duplicate]

What is safer? Before or after the fuse? In my case the varistor is 10mm, 275Vrms, and it is currently placed after a 250Vac, 7A, 20mm glass fuse. Would the varistor blow the fuse easily if placed ...
0
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1answer
37 views

Understanding lower voltage’s effects

Let’s say I have a surge protector that has a 15A cable that is rated 1875 watts at 125V. If my voltage is low, let’s say 105V the amount of watts it can supply will drop? So its max safe output ...
1
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1answer
81 views

Why did these two ethernet switches die (again)?

For the second time in four months I find that the two ethernet switches in my family room are dead. These are Netgear GS105 unmanaged switches labeled SW1 and SW2 in the attached figure. By dead I ...
0
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1answer
44 views

Plastic Plugs in Surge Protectors or UPS

Would plugging 4 out of 7 outlets in a surge protector or UPS with plastic “safety plugs” to keep out dust/dirt harm the product in any way? I know that plastic is an insulator and it might affect ...
0
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0answers
42 views

Can we use tvs and mov together for thruster?

I want to know if we can use both tvs and mov varistor together ? What will be good for thrusters ? And placement between esc and thruster or before esc? Update: system voltage is power supply ...
0
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1answer
39 views

Max power from surge protector

I have a surge-protected outlet from a renowned brand. On the back it is written 10A 230v Up voltage = 0.8KV Spd class III. The 8 outlets are Shucko format. I do not understand that up voltage. ...
0
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1answer
101 views

Why often is used a varistor 7D471K for 220-240vac surge protection rather than a lower nominal voltage one?

In my "supposedly" surge protected power stripe there is a varistor for surge protection configured to simply short-circuit the entrance wires in case of surge. Checking the model it's a MOV-7D471K ...
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0answers
35 views

UPS vs Surge Protector regarding short circuits and quality of power

I did research before posting and it seems a UPS filters power so that it is constant and “filtered” additionally it seems to be able to protect against short circuits. Does a surge protector have ...
0
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1answer
114 views

I am failing to understand the difference in Impulse Sparkover voltage vs DC Sparkover voltage of GDT

Lets say I want to use a Gas Discharge tube for indirect lightning protection, and I have a tvs diode in parallel with GDT. Since this is indirect lightning and has a fast waveform, should the tvs ...
0
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1answer
55 views

Question related to TVS Diode in series

I have a questions on my mind, and I hope that can be answered. The line to ground voltage is 54Volt, and I would like to know if it is possible to have two bi-direction TVS diode in series. I will ...
0
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0answers
58 views

Anyone hear of GMOV - Metal Oxide Varistor in series with Gas Discharge tube

I am currently working on protecting the Network switch. The network switch is powering a camera outdoor. I have read through multiple tvs components, and found advantages and disadvantages. Until ...
0
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2answers
103 views

Two Gas Discharge Tube in parallel; a fast acting gas acting tube and a gas discharge tube

I want to know what happens if we put two gas discharge tube (fast acting GDT and a GDT in parallel), and a tvs diode in parallel. Would there be an issue in putting GDT in parallel? Datasheet of ...
0
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1answer
68 views

Gas discharge tube datasheet impulse sparkover specification

What does the Impulse Sparkover at 100 V/us and 1000 V/us mean? Does it have anything to do with arcing? How does the impulse help us decide with which GDT to choose?
2
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3answers
119 views

Circuit Protection against 500V surge

With my firm we're trying to get the CE certificate for our device and one of the tests is the protection against power surges. For this, the test company is using a device that's connected to our ...
0
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0answers
22 views

How do I calculation to see if Thyristor complies with DO-160G indirect lightning protection

I have been working with TVS diode and found that the capacitance of tvs diode is large; therefore, I will not be able to use tvs diode. Thyristor, on the other hand, has low capacitance for high ...
1
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0answers
12 views

Surge Protection in a 3 Phase TT System

I am studying on the topic of Surge Protection Device (SPD) and I just couldn't figure out the proper selection of the Type 1 L-N SPD rating for a TT-system. Assuming a lightning current (LPL 1) of ...
0
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1answer
123 views

DO-160 indirect lightning requirement confusion

I am looking at many tvs diode online, and I wanted to know how to calculate to check if it complies with DO-160 indirect lightning surge protection. For DO-160, there are Waveform 3, 4, 5A&B, ...
0
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1answer
77 views

Lightning Surge Protector that complies with DO-160. Indirect lightning waveform, Gas Discharge tube or MOV in parallel with tvs

Would it be wise to put Gas discharge tube in parallel with tvs diode? OR Would it be better to put MOV in parallel with tvs diode? Also when deciding on tvs diode, how does indirect lightning ...
1
vote
1answer
233 views

A TVS for lightning surge protection

A camera will be mounted outside and powered via POE to Aruba 2540 network switch. I don't want indirect lightning surge to travel into the network switch. I don't care if the camera gets destroyed. ...
0
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2answers
82 views

Using a Main Surge Protector for only branching out other surge protectors

Whenever I try to find information about this question it always says that it is not good to plug in a surge protector into a surge protector because you can overload or overheat the protector or ...
2
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1answer
116 views

230VAC line voltage sensing using MCU pin

I Am designing a circuit to detect the presence of AC line voltage.It is basically to detect the switch On/OFF for a load. Here is the circuit. Here Input resistor ladder to step down the voltage. ...
1
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1answer
70 views

MCU conneected to AC Mains

I am developing a PCB which is having control MCU circuit, it will control the relays. Relays output are connected to 230V AC mains load (~100W load). This PCB is mounted on a cabin where people cant ...
0
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1answer
47 views

How do surge protectors interact with existing circuit protection?

I recently bought a power strip with a surge protector and it came with this warning. Do not install this product if there is not at least 10 meters (30 feet) or more of wire between the ...
0
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1answer
42 views

Surge protector outlet with altered grounding potential

I realized that I have a voltage difference of 5 to 80 V AC (orange in Fig. 1) between the protective conductors (grounding cables, "PE-Leiter", yellow-green contacts in drawing) before vs. after a ...
4
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3answers
791 views

Polarity of gas discharge tubes

Do gas discharge tubes used e.g. for surge protection have a polarity, i.e., do they protect in both directions (i.e., depending which wire is hit, or if it is a positive/negative lightnings? The ...
1
vote
1answer
63 views

Grounding for surge protection for telephone/internet/data lines

After my router broke in a thunderstrorm, I am trying to establish surge protection for power lines as well as (this question) for telephone/internet lines. I found devices such as Tupavco TP302, ...
0
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0answers
33 views

What's the proper way of mounting surge arresters on TN-S system?

I'm attaching a diagram with surge arresters put on each line. Most of the experts in the field say a proper defense against lightnings and switching events has three surge arresters - one between ...
0
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1answer
69 views

Transient current capacity of sacrifical Zener diode

The common wisdom is that Zener diodes are suited for only very low power surge protection because of their low current capacity. But what about where it was used as a sacrificial device for clamping ...
-1
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1answer
200 views

AC line surge protection with GDT in series with MOV

We often use GDT in series with MOV to protect AC lines as below. But i have Question as for 230V AC line and 275V Rated MOV - What Should be the Breakdown voltage of GDT ? Three options available :...

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