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ELECTRICAL INSPECTION, DIAGNOSIS, REPAIR ALUMINUM SECs & WIRING ALUMINUM WIRING HAZARDS AMPS & VOLTS DETERMINATION DEFINE AMPS VOLTS WATTS VISUALLY DETERMINE AMPS & VOLTS VOLTAGE at the SEC VOLTAGE by EQUIPMENT LIMITING FACTOR sets AMPS SE CABLE SIZES vs AMPS UNDERGROUND SERVICE LATERALS ALUMINUM SECs & WIRING MAIN DISCONNECT AMPACITY PANEL AMPACITY ELECTRIC METERS & METER BASES ELECTRIC METER BASES ELECTRIC METERS INSPECTING METERS & BASES AMPACITY - the LIMITING FACTOR CIRCUIT BREAKER FAILURE Classified CIRCUIT BREAKER WARNING DEFINITIONS of ELECTRICAL TERMS DIRECTORY OF ELECTRICIANS ELECTRIC METERS & METER BASES AMPACITY - the LIMITING FACTOR ELECTRIC PANEL AMPACITY ELECTRIC PANEL INSPECTION ELECTRICAL BASICS Electricity Basics - how it works Electrical Circuit ID, Map & Label Electrical Circuits, shorts Electrical Code Basics Electrical Conduit Tips Electrical Definitions Electrical Grounding Basics Electrical Wiring in Old Houses Electrical Outlet-how to add Electrical Splices, how to make Electrical Tools & Tests Electrical Wire Stripping Tips Electrical Wiring Books & Guides ENERGY SAVINGS in BUILDINGS FEDERAL PACIFIC FPE HAZARDS GROUND SYSTEM INSPECTION KNOB & TUBE WIRING LIGHTNING PROTECTION LOW VOLTAGE BUILDING WIRING MAIN DISCONNECT AMPACITY MULTI-WIRE CIRCUITS PUSHMATIC - BULLDOG PANELS RUST in ELECTRICAL PANELS SAFETY FOR ELECTRICAL INSPECTORS SE CABLE SIZES vs AMPS SQUARE-D RECALLS UNDERGROUND SERVICE LATERALS VOLTAGE MEASUREMENT EQUIPMENT WIND TURBINES ZINSCO / SYLVANIA HAZARDS More Information InspectAPedia Blog - News Updates Air Conditioning & Heat Pumps Bookstore Electrical Environment Exteriors Heating Home Inspection Insulate Ventilate Interiors Mold Inspect/Test Plumbing Water Septic Roofing Structure Accuracy & Privacy Policies Contact Us |
This article explains how to estimate the electrical service size, (or "electrical power" or "service amps") at a building by visual examination of the service entry cables, electric meter and meter base, electrical service panel, main switch, and other details. Visual inspection and use of digital multimeters(DMMs), Volt-ohm meters (VOMs), neon testers, and electrical inspection safety are discussed. Photographs and sketches illustrate electrical panels, meter bases, and electric meters. One of the most frequently asked questions at ASHI Education Seminars and Conferences is "How do I determine the service amperage?" It's not as difficult as one may think to get a reasonable handle on the electrical service capacity at a building without sophisticated analysis. But there are some pitfalls, and the process itself is dangerous. The articles from which much of this online material originated appeared first in the ASHI Technical Journal, Vol. 2. No. 1, January 1992, "Determining Service Ampacity," Dan Friedman and Alan Carson, and the ASHI Technical Journal, Vol. 3. No. 1, Spring, 1993, "Determining Service Ampacity - Another Consideration," Robert L. Klewitz, P.E., with subsequent updates and additions to the original text ongoing to 2/19/2006. Reprints of the originals and reprints of the Journal are available from ASHI, the American Society of Home Inspectors www.ashi.com Readers of this article should also be sure to review Safety Hazards and Safe Electrical Inspection Procedures for examining Residential Electrical Panels. © Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.VOLTAGE at the SEC - How to figure out Electrical Service Voltage by visual examination at the service entry
In lay terms, the service conductors are also called
the service entry cable or SEC. Underground wiring up to the building
is called a service lateral. A 240V electrical service [three-wire figure at left] will include
three wires connected to the building - the two 120V "hot"
legs which together provide 240V, and a third grounded conductor.
However simple visual examination from the ground is not a certain proof of voltage available in the building. In a few unusual circumstances, all three wires may be present but one of them may be disconnected at the utility pole or masthead. Such "mistakes" occur during temporary hookups in new construction or renovation. Could there be 240V service to a building with only two wires? Yes but not normally in the U.S. Some Canadian rural properties served by long private wires may have only two overhead conductors on a 240 volt service. For these systems ground connections are made only at the building, not back to the utility company's lines. In the U.S. this would be unusual but be alert for it, especially at rural properties.
Notes to Table:
... Technical Reviewers & References
Use links just below or at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website. AMPS VOLTS DETERMINATIONDEFINE AMPS VOLTS WATTS VISUALLY DETERMINE AMPS & VOLTS VOLTAGE at the SEC VOLTAGE by EQUIPMENT LIMITING FACTOR sets AMPS SE CABLE SIZES vs AMPS UNDERGROUND SERVICE LATERALS ALUMINUM SECs & WIRING MAIN DISCONNECT AMPACITY PANEL AMPACITY ELECTRIC METERS & METER BASES ELECTRIC METER BASES ELECTRIC METERS INSPECTING METERS & BASES AMPACITY - the LIMITING FACTOR
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ELECTRICAL INSPECTION, DIAGNOSIS, REPAIR AMPS VOLTS DETERMINATION More Information InspectAPedia Blog - News Updates Air Conditioning & Heat Pumps Bookstore Electrical Environment Exteriors Heating Home Inspection Insulate Ventilate Interiors Mold Inspect/Test Plumbing Water Septic Roofing Structure Accuracy & Privacy Policies Contact Us |
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05/25/2009 - 1/16/1993 - InspectAPedia.com/electric/ElecSECVolts.htm - Web page design & content © 2009-1993 Copyright Daniel Friedman All Rights Reserved - InspectAPedia® is a Registered U.S. Trademark