Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [surge-protection]

Questions about protecting electrical devices from voltage spikes.

0
votes
1answer
51 views

Purpose of backup fuse in SPD

I am trying to understand the main purpose of backup fuse used in SPD (Surge Protection device). Is this used to protect the SPD from high AC current but still allowing surge current to pass or does ...
1
vote
1answer
165 views

On a wire designated as '3x14AWG' what does the '3x' part mean?

On a wire designated as '3x14AWG' what does the '3x' part mean? It is on a wire that is part of a surge protector power strip.
7
votes
4answers
2k views

Is it Safe to Plug an Extension Cord Into a Power Strip? [closed]

Just a bit of context, I am a technology enthusiast. I love everything from software to hardware, Windows to Linux, Computer to Phone, and everything in between. So, I wouldn't be surprised is my ...
0
votes
0answers
40 views

Protection against ESD/EFT/Surges

One of my project architectures looks like this: GPIO / 595 output / 12 VDC wire lengths will not exceed 25 cm. I have faced MCU lockup issues due to EFT in the past and want to make sure this ...
2
votes
3answers
83 views

Surge Current on PCB

When designing a PCB, do you need to worry about the inrush/surge current or just the continuous/RMS current on the board? Everything I have seen including IPC documentation is for continuous current....
0
votes
1answer
53 views

Home voltage stabilizer circuit

I am designing a 12000W voltage stabilizer transformer. I saw in another design that they use on the AC neutral a 10W resistor linking on the branch on relay contacts so that the neutral is taken from ...
0
votes
1answer
50 views

How can I simplify my design for a Surge Protection Device (SPD)?

I have found a basic design for a SPD and I would like to simplify it. However, I have little experience designing SPD circuits. This is my parallel type SPD circuit with embeded LED indicator: In ...
5
votes
1answer
149 views

230VAC dimmer MOSFET failure at surge test

Our dimmer prototypes work fine, but fails surge test, as per 61000-4-5, 1/50us. Circuit is isolated dimmer for 230VAC different types of bulbs. It uses 2x N MOSFET as switch. V503 detects zero ...
0
votes
1answer
33 views

Power strips show fault in some outlets but not others

I'm not sure if this is on topic or not, but I thought I would ask. I have a few power strips (surge protectors) in my house that I use for computers, TV, etc. Some of these have a "fault" or "surge"...
0
votes
2answers
110 views

How does diode clamp protection work?

I am not able to understand how diode clamp protection works. Considering the diode clamp protection as shown in Figure 1: When the input voltage (Vin) becomes more than power supply voltage (Vss = ...
2
votes
1answer
40 views

Circuit protection component arrangement

I was reading this thread and decided that in general it's better to place the reverse polarity protection diode D2 after the TVS rather than before it, and to instead use a bidirectional TVS for D1 (...
0
votes
2answers
41 views

i dont want to change voltage but only regulate input voltage

It is my first power supply project. I will supply 300 watt vehicle audio amplifier with this supply. I will use nominal 24V and 14A at my system Vehicle input 24V and my amlifier 12V-30V but when i ...
0
votes
1answer
68 views

TVS diodes for Ethernet/PoE?

I am getting confused in selecting TVS diode for Ethernet Interface. Should I connect one bidirectional TVS diode across a ...
0
votes
1answer
42 views

Separate ground for gate opener control box?

Is it worth electrically isolating the control box of a gate opener from a well grounded steel fence? Or does the grounding of the fence have the same effect? My house is in a very lightning prone ...
0
votes
0answers
22 views

Lower VPR in SPD (Surge Protection Device) is more protective?

If you have a universal power supply that can accept 88v to 264v connected to expensive security system. Isn't it if you use a 120v SPD (Surge Protection Device) with VPR (Voltage Protection Rating) ...
2
votes
1answer
69 views

Interpretation of EN 61000-4-5 Surge requirement on a DC Power Port

I am trying to understand how to treat the DC power port on my industrial device (read: will be used in CNC machine shops and industrial processing plants and the like) should be tested according to ...
0
votes
2answers
33 views

Using Belkin 6-Outlet Surge Protector in Morocco without a Converter [closed]

Morocco uses the 220V/50Hz standard, and I was trying to use the following power strip I bought in the US with only a adapter (no converter): https://www.belkin.com/us/p/P-BE106000-06/ When I ...
0
votes
1answer
74 views

Can car alternator back-emf damage electronics?

I know on startup a motor or generator produces back-emf and current ( correct me if I'm wrong, been a while since I've worked with electric machinery ). Thus, it'd be reasonable to expect that when ...
0
votes
1answer
95 views

LTC4366 killing MOSFETs

I designed a circuit around LTC4366 as per the picture below. However numerous MOSFETs have been damaged and become useless. Mosfets used : STH12N120K5-2; IXFT50N85XVH; STW13NK100Z - All are rated to ...
1
vote
0answers
127 views

MOVs, thermal fuse and thermal runaway behavior

Above picture is that of a Belden surge protector with some kind of cloth covered over the MOV and thermal fuse for isolation to promote more conduction. I don't want to cover the whole thing with ...
0
votes
1answer
48 views

What could be the function of three components of this surge protector?

An SPD module has the following circuit diagram: I'm trying to understand how it functions. I only know the varistor symbol on the left corner I guess it is a MOV and suppresses transient voltages. ...
0
votes
3answers
67 views

Surge or other suppressor I can use, to prevent tool blowing fuse if blade sticks [closed]

I want to say up front, that this question involves minor modification (transient surge/current suppression) to the power supply side of a power tool. Usually I'd be the last to do anything like this (...
1
vote
2answers
85 views

ESD diode selection based on VCC of the IC

I have a question about TVS diode selection. This kind of question is already discussed in previous questions. ESD Diode - GPIO Microcontroller Selecting a TVS for ESD protection For protecting vcc ...
-2
votes
1answer
68 views

Is this a Disconnector beside MOVs?

This is inside a power strip surge protector. What is that tubelike thing between the MOVs? Is it the disconnector (written "22IR UMI, 4A, 102 Celcius, 250V")? Can anyone show me images of a ...
6
votes
1answer
243 views

UL Clamping Voltage Ratings on Surge Protectors

I have been looking for some new surge protectors for my devices, and I am having trouble understanding the meaning of the voltage clamping ratings on many surge protectors. It seems that all of the ...
0
votes
1answer
147 views

Calculating energy of transient/surge handled by metal oxide varistors (MOV) or surge suppressors?

As I get to know more about the MOV operation, there are more things needed to understand. My MOV (V420La20AP) has Varistor voltage of 680 Vrms (10%) at 1 mA, and maximum clamping voltage of 1120 V ...
0
votes
0answers
66 views

Choosing Varistors for 61000-4-5

I would like to know what kind of surface mount varistor I need to choose to pass IEC 61000-4-5 Class II which is 1kV for a low voltage (24V dc) circuit When you want to choose Varistors or MOV you ...
-1
votes
1answer
191 views

What is Metal Oxide Varistor (MOV), meaning of its specification and how it protects circuit from over-voltages?

Hello, I have a circuit in which a voltage source is connected to some sort of RC Load. To protect this circuit , there is an Metal Oxide Varistor (MYN15-681K). The Pics of circuit and datasheet ...
2
votes
0answers
72 views

High power / high current clamping circuit

I am looking for ideas on how to clamp high energy surges in the input of a high current / high power system. The input to the system is 24V. During steady state, the system sources 85A of current ...
0
votes
0answers
74 views

Surge Protection for Optocoupler

Resistor Specification Edited: 24July18 Does the TVS + Zener diode provide adequate surge protection to the opto from voltage spikes and indirect lightning hits? The resistors are smd type with ...
2
votes
2answers
462 views

Auto turn off switch during power outage

In my area power outages are a daily routine. And power surges, which occur when the electricity comes back, makes it even worse. To avoid damage of the electronic devices we try to unplug them ...
0
votes
0answers
26 views

Power Outages and Surges

I live in South Africa where we experience frequent power outages due to so-called "loadshedding". With this, there have been numerous cases of damage to appliances due to surges, usually when power ...
1
vote
2answers
134 views

What kind of protection do these Ethernet “surge protection” diodes provide?

I was considering a network run outside of my home, and purchased a super-cheap "Ethernet Lightning Protector" because there was little to lose, and I wanted to understand its workings. Below you can ...
2
votes
1answer
67 views

Can someone explain the working of this Surge Suppression Circuit

This is an old circuit which is still being used. I am curious to understand that if 600 VAC is applied to AC side of the three phase rectifier which has diodes, and on the DC output side of the ...
0
votes
2answers
81 views

Automatic cut mains power on a thunderstorm

I am a software engineer with only a basic experience with electric/electronic engineering. I live in a rural area subject to thunderstorms, my house is the end of the line from street poles. It's ...
0
votes
0answers
37 views

TVS Diode Response

I am trying to understand what would the response of the TVS diode be when I will apply +5V and -5V across the device. From what I understand is that when I will apply +5V and Ground across Pin1 and ...
3
votes
3answers
204 views

History of ESD protection

These days you can't read anything about electronics without hearing about the dire consequences of omitting ESD protection from your designs. It seems this wasn't always the case. If you look at ...
1
vote
2answers
259 views

overshoot and undershoot on 3 volt pulse

i am interfacing a system, this system output signal of 200ns digital pulse with repetition time of every 3ms. Ideal voltage of signal would be 0v to 3.3V but signal coming from system have high ...
2
votes
2answers
269 views

Lightning protection for underground loudspeaker wires

I am tasked with running a loudspeaker to a remote building. The total run length is around 275 feet, with the outdoor portion being around 165 feet. The cable is Cat5e 24awg unshielded, silicone ...
4
votes
2answers
2k views

How to choose the right Metal Oxide Varistor (MOV)

I would like to protect the input of a transformer against high voltage surges but I don't understand how I have to proceed to choose the right MOV despite what I read so far about them. Below is how ...
3
votes
3answers
109 views

How to protect againt surges if working and maximum voltage are too close

I have a circuit that I want to protect against surges and eventual peaks (e.g. indirect lightning surges) and I was thinking about TVS diodes or MOV. The situation is: -My circuit input is 48V that ...
1
vote
1answer
222 views

Triac misfires because of noise from inductive loads

The product is a wifi enabled smart switching device. One device has 4 different channel for four different appliances to be connected to the product. Each channel has a pair of optocoupler and triac ...
0
votes
2answers
52 views

What stats to look for in a surge protector, how to compare them and what are recommended some European surge protector brands (and models)? [closed]

I read that joule rating is more like the lifespan of a surge protector, some don't even list them, for an example the german brand Brennenstuhl only lists their surge protectors with leak through amp ...
10
votes
2answers
545 views

Relay protection when proper TVS at load cannot be implemented

I'm currently developing a product which has a simple SPDT relay that can be controlled by an operator. To the end-user, only the common, normally open and normally closed contacts are available. The ...
2
votes
1answer
316 views

Pc power supply Ac in rush current overloading inverter

I have a PC consuming 400 watts hooked up to an 220 VAC automatic backup 1500VA 12V dc inverter since AC grid line is not 24/7 in my country. The main problem is that sometimes when the AC power goes ...
0
votes
1answer
85 views

How to UPS-protect this “dual source” setup? [closed]

I'm analyzing how to best protect a setup comprised of a NAS/Router/Wimax from power surges. A very simple diagram is this: When I write "dual source" (term which I just invented) I mean that the ...
0
votes
0answers
33 views

Water pump, PSU and surges

I've got a home-built watercooler that I've been using for more than a decade on my personal PC. The unit has a single switch for the AC mains (120V 60hz) that splits to power both the AC waterpump, ...
8
votes
2answers
771 views

Connecting TVS before or behind Ethernet transformer?

I looked at several designs and recomendations. Why do TVS diodes sometimes connect before and behind transformer? What are the pros and cons of connecting before or behind?
0
votes
1answer
125 views

Distance between surge arrester [closed]

I'm installing surge arrester to protect a server room full of machines using the following page as a guide http://engineering.electrical-equipment.org/electrical-distribution/how-choose-surge-...
4
votes
3answers
422 views

ESD protection diode circuit confusion

In the following circuit, my understanding is that when there is a spike or rise in the data line higher than Vcc, the top diode conducts and the voltage flows into the path to protect the downstream ...