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Recent content by rlaft

  1. rlaft

    Replacing a 3-way Ceiling Fan Pull Switch

    1. Remove the switch from the fan with the wires 2. By "feel" see if the wires are making cintact where they are going into the holes. If they are excessively loose and/or pull out, you probably should replace the switch. 3. Connect an ohmmeter probe to the black wire and the the...
  2. rlaft

    Odd distribution voltage

    This note is just to provide some closure. As I reported earlier, I found a tranformer vendor which will provide the custom wound tranformer with taps at a reasonable price. More recently, I finally also found a GFI manufacturer which will custom modify their 120 vac GFI's to accept 80 vac...
  3. rlaft

    Odd distribution voltage

    If I understand busbar's suggestion, the 240v winding would be connected to 208 v, and the 48 v secondary would then be 41.6v. If I connect the H1 and X1 togeter, it seems that I could buck the distribution voltage of 120 v. phase to neutral down to 78.4v which would be perfect. His post...
  4. rlaft

    Odd distribution voltage

    Since writing this post, I have gotten estimating prices on a custom wound 480/138-80 vac 3 phase transformer. The prices per KVA are more than low enough to make this an economically attractive alternate for the use of variacs. So that leaves me still with the challenge to find an economic...
  5. rlaft

    GFI protection at 80 vac

    Resistance heaters will provide heat directly proportional to the line voltage squared assuming their resistance remains constant. The heaters that I plan to use are called mineral insulated (MI) and the heating conductors are completely encapsulated by a metal sheath. Nevertheless, we must...
  6. rlaft

    GFI protection at 80 vac

    I am planning on installing a power distribution system to provide 80 vac for heating inside vacuum chambers. 80 vac is the accepted limit to prevent the occurence of corona which occurs violently with higher voltages as the absolute pressure is being decreased. These chambers may be...
  7. rlaft

    I was at my brother-in-laws for din

    To emphacize what smcbride is saying, I would be willing to bet that the problem will be found with the neutral side of the circuit. Look at the connection bar for all of the neutrals and the bare grounds. Check the tightness of those connections. When the lights are flickering, measure the...
  8. rlaft

    Odd distribution voltage

    I need to install a distribution system to provide 138/80 vac 3 phase voltages into a vacuum test chamber. I am looking for alternatives for a method of producing this voltage from the more typical distribution voltages (208, 240 & 480). Also, I am looking for an economical source of GFI circuit...
  9. rlaft

    GFI for non-standard voltage

    I have looked at several manufacturer's specifications for voltage levels. The lowest I have found is 92 volts. Just now I looked at Hubbell and theirs are 120 v +10%/-15%. I sent them an e-mail and they simply said it would not work at lower voltages. If I was representing a manufacturer, I...
  10. rlaft

    GFI for non-standard voltage

    The higher voltages are in excessof 80 vac (RMS). They can initiate the corona under certain low absolute pressures. To prevent corona we typically use 120 vac fed variacs with a mechanical stop at 80 vac. This is an expensive solution and therefore, I am hoping to have a transformer custom...
  11. rlaft

    GFI for non-standard voltage

    I am planning on installing a power distribution system to provide 80 vac for lighting and heating inside vacuum chambers. 80 vac is the accepted limit to prevent the occurence of corona which occurs violently with higher voltages as the absolute pressure is being decreased. These chambers may...
  12. rlaft

    240 volt GFI protection

    I would like to find out who makes GFI's for voltages different than 120 vac. I need one for 80 vac.
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