Huh?! In the USA, the small blade should be "hot", and the large blade should be "neutral"...end of story!
AC cord polarity?? Does it matter???????
I've just noticed that from experimenting with preterminated factory builty cords that not all companies use the same polarities. Even with two stock cords, one from USA made in China and one from China made in China for USA the polarity of the cords are reversed. All my Synergistic cords are one way, my Electraglide is the other way and other cords from different manufacturers are different. The poles are reveresed from one cord to the next. Now I'm really confused to the polarisation issue as if different companies use one polarity and other companies use the reversepolarites, then it's a guess wether or not one system is in the right polarity or if just certain components are properly polaroized. It appears that in the US made cords I've noticed both direct and reverse polarity in cords. The Asian made cords are different depending on company as well. Does this then mean that polarity has no issue and it doesn't matter? Is there no right or wrong way to polarize a components ac? The cords in my system are giving half my components one direction of ac polarisation and the other half are in reverse.Perhaps it doesn't matter? I'm confused again!!!!
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Then plug in the component using the normal orientation, but with the cheater plug in place. If the component uses a grounded cord, make sure to connect the green ground wire on the cheater plug to the outlet plate screw. Turn the component on, and set the voltmeter to A/C volts. >>>>> >>"If the component uses a grounded cord, make sure to connect the green ground wire on the cheater plug to the outlet plate screw."<< [Jeffjarvis] >>>>>>>> Jeff I think you meant to say here, *do not*, connect the ground wire for the test. The equipment needs to be free of all earth grounds for the test. Infact if the type of ground cheater used is the brass or copper strap type, tape or cut off the ground strap so it does not come into contact with the receptacle cover plate screw. The screw is connected to the equipment grounding conductor. The reason the audio equipment must be isolated from earth ground is not because of the earth ground its self, it is because the equipment grounding conductor and the neutral conductor, (the grounded conductor), are connected together at the main electrical service panel neutral/ground bar. =========== ============================= Munufactures usually check to make sure they have properly wired the power supply's transformer primary correctly, sometimes they miss one. Another cause of reverse AC 120V polarity is after market power cords. Either the male plug or IEC female connector wiring is reversed. If you are using after market power cords check them for proper continuity, polarity. If the amp is pluged into one electrical outlet and the preamp in another, sometimes the polarity is reversed at the receptacle. Check for proper receptacle polarity. If it turns out one of your components power transformer primary winding was connected with reverse polarity and you are using an after market power cord just reverse the hot and neutral conductors at one end only. The male plug, or IEC connector end. Repeat the polarity test with the ground cheater to verify it is correct. This test will work for a preamp or power amp. For newer two wire cord and plug equipment such as DVD or CDP players this test procedure may not work. The case, enclosure, of the unit is floating and has no electrical continuity with the electrical power supply or electrical components inside the enclosure. Another thing about CDPs and DVD/SACD/DVDA players is the fact they use multiple power supplies. Jim |
>>"Of course if you decide to use a balanced power unit, all this is of no concern."<< [Nsgarch] >>>>> Maybe, True if all the audio equipment connected by ics is pluged into the same balanced power unit. ========== Nsgarch, What is your thoughts of feeding a balanced power unit from 120V? Jmho, I believe there would be better isolation if a balanced power unit was feed by 240 volt. Here is some reading material. Make note of how the utility companies bond the high voltage neutral and all the secondary neutrals together at every utility transformer. This can't be good for AC noise.... http://www.mikeholt.com/documents/strayvoltage/pdf/DangersofStrayVoltageandCurrent.pdf Jmo it appears to me the only way to get total AC isolation is with an isolation transformer fed from 240 volt. Jim |
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