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nec

  1. jar546

    What is a Health Care Facility according to the NEC?

    First, here is the definition: Health Care Facilities. Buildings, portions of buildings, or mobile enclosures in which human medical, dental, psychiatric, nursing, obstetrical, or surgical care are provided. [99:3.3.67] Now here is what that means: The term health care facility should not be...
  2. jar546

    NEC 2020 Question on GFCI Protection

    In the 2020 NEC, Section 210.8(F) introduced GFCI protection for equipment in certain areas. Which of the following best describes the specifics of this requirement in relation to HVAC equipment and its applicability to receptacles? A) GFCI protection is only required for HVAC equipment...
  3. jar546

    GFCI Protection Requirements NEC 210.8(D) in the 2023 NFPA 70

    Some big changes for 120/208/240 vac appliances: 210.8 (D) Specific Appliances. GFCI protection shall be provided for the branch circuit or outlet supplying the following appliances rated 150 volts or less to ground and 60 amperes or less, single- or 3-phase: (1) Automotive vacuum machines...
  4. jar546

    Electric Utility Companies Don't Play By The Same Rules

    You can see the difference here as shown on FPL's White Book between the NEC and the POCO
  5. jar546

    Temp Service and Two Ground Rods - What is Required?

    NEC 250.53 Covers the necessity for a supplemental ground rod or in reality a supplemental grounding electrode. What if the POCO only shows one on their detail for a temp service? Do you follow the minimum standards of the NEC or do you only require what is shown on the electric utility's diagram?
  6. jar546

    NEC 310.3 Changes to Conductor Types in the 2023 NFPA 70

    This section correlates with the UL listing requirements for testing terminations — such as copper-aluminum, revised (CO/ALR) devices, and other connectors — suitable for use with aluminum conductors. The electrical industry has developed AA-8000 series aluminum alloy materials and connectors...
  7. jar546

    Copper Clad Aluminum Wire is Making a Comeback

    In the early 1950s, copper shortages led cable manufacturers to develop an alternative conductor made from electrical-grade 1350 aluminum. By the 1960s, aluminum building wire had become popular across the United States. However, by 1968, it was identified as a hazard due to thermal instability...
  8. jar546

    Minimum Feeder Size and Voltage Drop Calculation National Electrical Code (NEC)

    OK Electrical Inspectors and Electricians, is the following scenario I put together correct? The minimum size copper wire type THHN feeder for a 125 amp sub panel 100' away from the main panel in a 120/240 volt AC system, taking into consideration the National Electrical Code and maximum...
  9. A

    Low temperature hydronic baseboard heaters underneath receptacles NEC

    This board a huge help to the general public, thank you to all who take time to respond to questions. I am installing hydronic baseboard heaters underneath receptacles. Does anyone see a problem with this based on; Low 120 degree temperature system, heat generated by water heater and not a...
  10. jar546

    Water Heater electrical code violation by design

    I just caught this one in plan review and though I would add this as some trivia. Here is the situation. Level 2 remodel of condo which includes a new water heater The panel schedule showed the following: A double pole 60A breaker with #6awg cu wire to a 4500w electric storage water heater...
  11. jar546

    Name the Electrical Violation Photo

    This was discovered after a work without permit was called in by a neighbor. Looking at electrical only, what violation(s) do you see? Cite the NEC code for good measure.
  12. eyan50495

    Fire Req: Electrical Room w/ WH & Ref. Compressors?

    Hi We have a commercial space, Type VB, 1 story + basement, fully sprinklered building. We have an electrical room in the basement with rated walls, panic bar and sprinklers. The owner wants to put the water heaters and refrigeration compressors into this room as well. We read that the water...
  13. jar546

    90°C Wire for Feeder

    So here is the scenario. Would you allow this setup? An 800A MDP (with service disconnect) has to feed a panelboard with a total load of 400A which includes continuous and non-continuous loads. The breaker in the MCP has 75°C terminals as expected and so do the lugs in the panelboard it will...
  14. jar546

    Tankless Water Heater

    If an electric, tankless water heater has a tag showing it is listed by an approved agency with the following information on the label: 240v, 10kw, 42A, what size wire and circuit breaker would be required by code in the absence of manufacturer's installation instructions? Please don't turn...
  15. jar546

    Do you have to seal holes on NEMA 3R enclosures with weatherproof blanks?

    Here is an example where the installation of a new ATS changed the feed location from a NEMA 3R meter enclosure from bottom side to bottom. This left an open hole (seen in photo below) on the bottom right. The hole is located below the level of live parts just in-case that matters to you...
  16. jar546

    Why you can't run NM (Romex) to an outside condensing unit

    Simply put, NM cable is not allowed in wet locations and even in conduit outside, it is not allowed. This is nothing new, it has been the code requirement for a very long time. This is how we get there. NEC Article 334 covers NM cable. Type NM, NMS & NMC are part of this. None of them are...
  17. jar546

    What's wrong with this service disconnect replacement

    In this case the existing meter-base was left in place but the service disconnect was replaced. As you can see by the two photos, the electrician has a violation. (click on photos to enlarge)
  18. jar546

    A Lesson in Bonding Service Enclosures

    Today's lesson is brought to you by our own Chris Kennedy who "schooled" me today on a situation that I encountered. He and I are back and forth trying to school each other and as of right now, he is ahead by 1. So here is what I was looking at, a simple 120/240 single phase, 400A commercial...
  19. jar546

    Electrical Code of the Day 20 February 2019

    Here is one that is often overlooked: 408.3(F)(1) High-Leg Identification. A switchboard, switchgear, or panelboard containing a 4-wire, delta-connected system where the midpoint of one phase winding is grounded shall be legibly and permanently field marked as follows: “Caution _____ Phase Has...
  20. jar546

    Tap Rules for Conductors

    Where on this photo do you see where the tap rules apply, if at all? This is a step up transformer 208 3ph primary to 400/231 secondary to run a machine made in Europe. Thoughts?
  21. jar546

    Generator Bonding Jumper (leaving it installed)

    When is it OK to leave the factory installed bonding jumper that connects the neutral bar to the generator frame WHEN you don't have a separately derived system (the neutral is not switched in the ATS)?
  22. jar546

    The Wiring of Emergency Lights

    I think that everyone knows if a lighting circuit fails, the emergency lights must come on and those ELs must be fed by the same circuit as the light. There are a few other things as seen in this illustration. I don't think enough attention is paid to the exceptions of that section of the...
  23. jar546

    Mobile Homes and Ground Rods

    Now this should be a great topic of discussion. Let's evaluate a situation that I have encountered before. In a mobile home park certain sections in groups of 4 to 6 have an underground electrical service that supplies 4-6 meters and service disconnects. Then, each of those 4-6 service...
  24. jar546

    What would you do? Breaker Panel behind generator.

    OK, so you are called out to inspect a new generator and you find this. The generator company swears the new generator is in the same location as the old and the issue with workspace was pre-existing. You then find out that they will be changing the breaker inside that box and you will...
  25. jar546

    Does this stay or go?

    This is a 480/277 generator that has an ATS in an office building. As you can see, the neutral is bonded to the frame of the generator. The ATS confirms that this is not a separately derived system because the neutral is not switched. Should this factory installed bond between the neutral and...
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