Recent content by anagon
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Snubber for a 3kVA 240V to 110V transformer
Hey, Jim... I had no idea how to spec the snubber, so I chose whatever was in stock and affordable. If the MOVs absorb the turn-off kick, that's great. This kit is designed to run continuously so powerdown should only happen once every two weeks or so. I've put a 13 A fuse in series with the...- anagon
- Post #18
- Forum: Electrical Engineering
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Snubber for a 3kVA 240V to 110V transformer
I bought the following three varistors (130 VAC, 150VAC, 175 VAC): http://my.element14.com/epcos/b72220s0131k101/varistor-74-0j-130vac/dp/1004282 http://my.element14.com/epcos/b72220s0171k101/varistor-98-0j-175vac/dp/1004352...- anagon
- Post #16
- Forum: Electrical Engineering
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Snubber for a 3kVA 240V to 110V transformer
Welcome to Malaysia... It's worse in Indonesia though!- anagon
- Post #13
- Forum: Electrical Engineering
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Snubber for a 3kVA 240V to 110V transformer
Good point... it's normally about 243 V on each phase. We did have a scary situation last month. During a storm, 30 second long surges came about once every 2 minutes for half an hour... lots of long lasting surges. My multimeter said 290 V, but the lights were flickering (brightly!) so I don't...- anagon
- Post #11
- Forum: Electrical Engineering
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Snubber for a 3kVA 240V to 110V transformer
I've done some quick calculations and it seems an RC snubber can generate quite a bit of heat. A 0.5 uF capacitor would limit 110 V @ 50 Hz to about 17 mA. This would make 1.7 W of heat in a 100 Ohm resistor. But the units come as a whole and they're specced for up to 600 VAC, so I guess heat...- anagon
- Post #9
- Forum: Electrical Engineering
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Snubber for a 3kVA 240V to 110V transformer
Hi anorlunda. I'd prefer a DIY option since it'll be a lot cheaper, and surge protectors are designed to protect against infrequent surges, not regular inductive kicks. Good call with pennies but I think that shouldn't be necessary for the 110 V side since the transformer is isolating and the...- anagon
- Post #6
- Forum: Electrical Engineering
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Snubber for a 3kVA 240V to 110V transformer
Hi berkeman, I can't get 110 V power strips where I live... we only have 240 V kit here. Also, from reading reviews, surge protection in power strips seems a bit hit and miss. Some are good, some fail silently and leave you without protection. There's also the issues that one bit of equipment...- anagon
- Post #3
- Forum: Electrical Engineering
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Snubber for a 3kVA 240V to 110V transformer
Hey... how's it going? I've built a step down box to run 110 VAC appliances off incoming 240 VAC (Malaysia). The only components in the box are a cooling fan (240 V) and a great big transformer. It's a single phase 30A output aluminium cored 240V->110V 50 Hz transformer that weighs about 25 kg...- anagon
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- Transformer
- Replies: 19
- Forum: Electrical Engineering
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Can I Use a Snubber for a Step Down Transformer? - Extra Info Appreciated!
Hey. Sorry to reference - I thought I better be polite and ask first :) Will read rules & post question. Thanks!- anagon
- Post #3
- Forum: New Member Introductions
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Can I Use a Snubber for a Step Down Transformer? - Extra Info Appreciated!
Hey... how it's going? I signed up because I have a quick question about a snubber for a step down transformer. I've already posted it on eeweb.com ... am I allowed to repost it here also? Extra info is certainly appreciated :) Thanks, - Leo- anagon
- Thread
- Replies: 3
- Forum: New Member Introductions