Questions tagged [gdt]

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votes
1answer
18 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
votes
2answers
51 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
votes
1answer
56 views

GDT in parallel with TVS diode. Should the clamping voltage of the TVS diode be equal to the DC breakover of GDT?

I am putting a GDT in parallel with TVS diode, and I want to know if I need to have clamping voltage of TVS diode slightly higher than DC breakover voltage of the gas discharge tube OR have clamping ...
0
votes
1answer
53 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?
4
votes
3answers
671 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
votes
1answer
92 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
88 views

Use GDTs or MOVs under low frequency over voltage protection

For power current transformer, the secondary is not allowed to open when the primary is conducting current of several KAs. So I want to design a over voltage protection circuit for this situation, ...
1
vote
0answers
368 views

MOV failures in DC

We are facing an issue in our protection circuitry. For the below DC design MOV between Earth is getting damaged in the site. MOV 2 & MOV 3 in the circuit is failing in the site. System is ...
2
votes
2answers
3k views

Connecting varistor and surge arrester in series

I have a doubt about proper values of MOV and SAR when they are connected in series as suggested in Epcos app notes (see below Fig. 12). For the 230 VAC mains they recommends SAR of 470 or 600 V, but ...
0
votes
1answer
340 views

Use of a Gas Discharge Tube to protect mains relay

I have a system that I am designing where I am interrupting the low side of a high voltage transformer with a relay, something like this (input: simulate this circuit – Schematic created using ...
2
votes
1answer
2k views

GDT in series with varistor

I often see GDTs are used in series with varistors, like this E100 is a 1500V/10A GDT, and RV100 is a 1.1KV diode varistor. For this circuit, I have two question What's the benefit to combine them ...