Bruce & others I have seen the combo of a Gas tube in series with a MOV but do not understand the design considerations. What I do understand is that Gas tubes have a rather slow action and need to go through zero crossing to extinguish. Is the MOV there to help this turn off issue? Why wouldn't I just use a Gas tube instead? Wouldn't the Gas tube's slow action significantly deminish the effectiveness of the suppression function? Is this combo still effective twards meeting IEC 1000-4-5?
What about the joule rating, wouldn't that still be an issue ? That is couldn't I still have MOVs that fail with safety considerations? Is it just an issue of eliminating the possibility of a shorted MOV to ground?..........This combo sounds interesting. Can any one enlighten me on what the advantages are of a Gas tube in series with a MOV and what the key design issues would be in making it effective? Regards Chris Wells Sr Des. Eng. Cutler-Hammer [email protected] C ------------- Original Text From: C=US/A=INTERNET/DDA=ID/fagley(a)tuv.com, on 5/16/97 11:53 AM: Chris: Have you tried a gas discharge tube in series with the MOV? This gets you out of the line to gnd agency problems.... Bruce Fagley TUV Rheinland EMC Test Lab Newtown CT. 203-270-1151 ext 119
