Questions tagged [surge-protection]

Questions about protecting electrical devices from voltage spikes.

Filter by
Sorted by
Tagged with
2
votes
1answer
45 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
vote
1answer
58 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
votes
1answer
34 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
votes
1answer
25 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
votes
3answers
639 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
48 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
votes
0answers
28 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
votes
1answer
52 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
votes
1answer
58 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 :...
0
votes
1answer
22 views

Probe max voltage (50:1)

I'm preforming some measurements with a differential probe and I'm not sure what is the correct attenuation ratio I should use (measuring about 300 V voltage drop on a varistor, which is a surge ...
0
votes
1answer
20 views

Why is the ground of the component, SP1050-04BTG, connected to the Power Supply of POE?

The SP1050-04BTG is a surge protector.
0
votes
0answers
19 views

Protecting a 5.1 amplifier

Some Yamaha models have no protection at all, except a fuse, maybe. I was thinking using a GDT, MOVs plus a line filter in an external box. And maybe adding a 12v latching relay (two pushbuttons: push ...
2
votes
2answers
70 views

Does whole house surge protection device (SPD) protect from Ground (PE) surges?

I've been researching on whole house surge protection devices and came across an Illustration of lightning current flow from a direct strike near the (protected) structure. From my understanding Type ...
0
votes
2answers
49 views

Surge arrester placement in substation

Is it enough to place surge arrester on the terminals of the transformer in a substation, or every power line entering the substation should have its own?
1
vote
2answers
70 views

transient protection for 0.5W laser diode switching driver

I'm some way into a project which involves switching 0.5W laser diodes at 100kHz, with a pulse of around 1us in width. I'm having issues with the diodes (which I don't have a datasheet for) failing ...
0
votes
1answer
56 views

How to protect against line transients?

I am designing a circuit that can detect if a cable is connected to mains voltage (e.g. via an external relay or switch). The device will be installed in electric cabinets. The circuit is tested and ...
1
vote
1answer
161 views

How do I correctly protect my MCU from resetting during a current surge on RF transmission?

I designed a PCB with a SIM868 module for data transmission. On the PCB, the MCU resets randomly on transmission start of the SIM module. On a breadboard setup, it worked just fine, even without caps. ...
0
votes
0answers
48 views

Why can't I piggy back / Daisy chain surge protectors or a surge protector and an ups? [duplicate]

Assuming I don't exceed the wattage rating of the whole system then why can't a piggy back let say ups to a surge suppressor in order to let say increase the protection of my system. Let's assume: I ...
0
votes
2answers
91 views

Why the replacement of 7812 with R-78E12-0.5, DC/DC makes the circuit not working?

I have this simple surge protector and soft start inside the PSU. My transformer is out of its specifications yields 21.3V after bridge rectification. And 0.1A load (12V fan for cooling pass ...
0
votes
0answers
23 views

Medium Voltage Synchronous Motor Protection [duplicate]

How is the wound field of a medium voltage synchronous motor protected from voltage surges? We do know that the stator is protected from surges by either one of the following: 1. RC Snubber Circuit 2. ...
17
votes
3answers
2k views

Varistor? Purpose and principle

In the AL9910 LED driver datasheet it shows a part, which I assume is a varistor, is it so? Varistors are shown to be connected across L and N lines, but here it is connected in series. Please explain ...
3
votes
1answer
102 views

How do select capacitor for 400A surge currents?

I have a 220nF capacitor in a series with my surge protection circuit. As can be seen from my spice simulation, the capacitor gets a surge of current passing through it under fault conditions, and ...
0
votes
1answer
348 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
192 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
6k 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
88 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
194 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
57 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
93 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
191 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
37 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
140 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
66 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
50 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 ...
1
vote
2answers
221 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
251 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
73 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
127 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
35 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
139 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
136 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 ...
2
votes
0answers
203 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
52 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
90 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
184 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
75 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
479 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
300 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 ...
-1
votes
1answer
408 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
96 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 ...