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ELECTRICAL ONSITE REFERENCE
Clearance from obstructions (trees)
No encroachment on neighboring properties
Clearance above ground (WARNING! CLEARANCES REQUIREMENTS CAN VARY, check with your local utility). IRC:
a. 10 ft. above walking surface, including deck or balcony (to bottom of drip loop);
b. 12 ft. above driveway;
c. 18 ft. above a roadway; and
d. 22.5 ft. above a pool (surface of water). 10 ft. measured horizontally from pool wall or diving structure.
Other types of clearances
a. 8 ft. (3m)- above a roof with 4&12 pitch or less;
b. 3 ft. (3.7m)- above a roof steeper than 4&12;
c. 3 ft. (1m)- clearance from operable windows, doors, porches, balconies, stairs, or any other locations from which a person could touch the service conductors; and
d. 12 ft. (30cm)- from communications wires/cables at any point, including the point of attachment to the structure
Service conductor condition (fraying)
Drip loop, splice
Service drop point of attachment
b. Below weatherhead or less than 24 inches above;
c. Non-stressing attachment to conductors;
d. 3 ft. minimum from openable window (bottom & sides only); and
Service entrance cables at mast (view/inspect/ID amperage rating)
Weatherhead head condition
b. Phenolic insulator
a. Secure attachment, bracing;
b. Approved type;
c. Path to ground (bonding); and
d. No other cables of any other type attached (internet, telephone, etc.).
a. Secure in socket, no damage
b. Height: to center- 44 inches to 66 inches
Photograph it, especially grounding and bonding components, labels (including SE/feeder conductor markings), and defects.
- Wear personal protective equipment (PPE), including glasses and gloves. Avoid synthetic clothing.
- Use proper inspection tools, including voltage detector, insulated handle screwdriver, and flashlight.
- Check for voltage on the panel exterior surface.
Inspection of Fusible Disconnects
If a fusible disconnect is located upstream of a load center at the home, the fusible disconnect is the service (first point of disconnect) where neutral/ground bonding takes place. If the fusible disconnect is remote from the home, the load center should have its own GEC and grounding electrode but the neutral bus bar should float. The load center is just a sub-panel.
Inspection of Load Centers
a. Identify panel location
b. Readily accessible and protected from physical damage
c. Damp/wet locations: electrical cabinet must be shielded from- or approved for- wet locations. Cabinets installed in damp locations should have a 3/16-inch (5mm) minimum air space between the cabinet and the wall.
d. Compliance with minimum working clearances
i. The working space in front of the cabinet should be a minimum width of 30 inches (76cm). 110.26 NEC
ii. A minimum space of 3 feet (1m) from a non-fireproof ceiling
iii. the working space in which the cabinet is located should have a minimum headroom of 6’-6’ (2m)
iv. Maximum height 6 ft.-7 in. (2m) to center of breaker switch in on position (center of handle on fusible disconnects).
e. Adequate illumination at interior-mounted panels
f. Adequate mounting
i. Proper anchors into masonry, concrete, plaster, etc. 110.13 NEC
ii. Flush mounting: when cabinets are mounted in cavities in non-combustible materials, the front edge of the cabinet should be recessed no more than 3/16-inch (5mm) back from the face of the finished wall surface. 312.3 NEC
g. The panel should not be exposed to potentially damaging conditions.
i. Temperatures above 104F (40C).
ii. Corrosive or explosive fumes, dust, or vapors.
iii. Abnormal vibration, or mechanical shock/impact.
iv. Tilting or unusual operating conditions.
v. Exception: if the panel has been designed to accommodate a particular condition and is identified as such by the manufacturer.
vi. Check panel exposure type (manufacturer’s label).
b. Unused openings should be filled with components designed for the purpose.
C. No exposed wiring.
a. Identify Amperage;
b. Evaluate condition;
c. Confirm marked as main disconnect;
d. Identify lack of a single disconnect;
e. Identify as defective if more than 6 hand movements are required to shut off all circuits.
f. Backfed disconnect should have a retaining clamp or clip.
Dead Front Cover
a. Test for current present on the dead front cover;
b. Confirm correct screw types used. If incorrect, don’t open: disclaim, recommend correction;
c. Check for missing filler plates;
d. Comment on any breakers in the Off position;
e. Examine and photograph labels and other written information;
f. Manufacturers label
i. Should be labeled s suitable for service equipment.
ii. Panel amperage rating is often listed here look for special information.
iii. ID manufacturer
1. Zinsco, Stab-lok, Sylvania, Westinghouse panels may be problems
h. Listed amperage rating
i. Identify amperage rating defects related to panel, disconnect and service entrance cables.
i. Circuit Directory
i. Presence and legibility
ii. Apparent integrity (comment if altered, or appears out of date)
Panel Cabinet Interior
a. Free of debris, paint/drywall overspray, etc.;
b. no open knockouts
Service Entrance Cables Connections
a. Confirm proper service entrance conductor connections to panelboard;
b. Identify as main disconnect or main lug
c. Comment on any line-side taps
d. Identify as a defect if the disconnect amperage rating exceeds SE cable or panel amperage ratings.
PANELBOARD GROUNDING AND BONDING
Service grounding refers to the connecting of the equipment grounding conductor (EGC; also known as the neutral conductor) to the grounding electrode. This connection should take place in the service panel only. The connecting device is called the main bonding jumper, and it may be a metal tie bar, a conductor, or the metal enclosure (cabinet or cutout box) itself. If the neutral bus bar is electrically isolated form the metal cabinet/box some type of bonding strap or bonding screw (typically green) should be visible.
The electrical system should be connected by a grounding electrode conductor (GEC)- using a clamp listed for that purpose- to a grounding electrode installed in the soil near the service.
Grounding Electrode Conductor Minimum Sizes
- 6AWG copper or 4AWG aluminum or larger if the only electrode is a driven metal rod/buried pipe
- 4AWG or larger if the only grounding electrode is rebar in the footing.
The grounding electrode conductor (GEC) should be connected to the grounded (neutral) service conductor at an accessible point between the load end of the service drop or service lateral and the neutral bus bar in the service panel or at the neutral bus bar. Typically, the connection is in the service panel, but may be in or near the meter.
The electrical system should be connected to a grounding electrode or electrode system. Only three types may be visible:
- Driven rods are the most common. They are required to be driven to their full 8 ft. length, but you will not be able to confirm length visually, so you should disclaim it. Rods may be driven at an angle not to exceed 45 degrees. When two 6’ rods are used they should be placed no closer together than 6 ft.
- Metal underground water pipes may serve as grounding electrodes. The GEC should be connected to the pipe within 5 ft. of the point at which it enters the ground. If an inline water meter is installed
- Ufer grounds are acceptable as service grounding. An Ufer ground is steel rebar encased in a concrete footing. The rebar is bent to protrude from the footing, providing access for clamping the GEC.
These types of grounding electrodes are acceptable, but not visible:
- Ground ring: a ground ring is a buried bare copper conductor that encircles the structure that it protects.
- Plate electrode
Note: In most jurisdictions, gas pipes should NOT be used as grounding electrodes.
The equipment grounding conductor is the (typically) bare copper conductor installed in branch circuits.
- Grounding and grounded (neutral) conductors should terminate on separate bus bars unless designed to accommodate more than one conductor type.
- Only one conductor per hole. HOWEVER, Instructions on the label may permit more than one grounding (EGC) conductor of the same size per hole.
Bonding is the use of conductors and other types of electrical components to establish electrical continuity between various metal components that enclose electrical conductors or equipment, or that may accidentally become energized.
Components that are commonly bonded are:
- electrical service masts;
- electric meter housings;
- load center cabinets;
- metal conduit;
- water supply pipes; and
- gas pipes (varies by jurisdiction)
Bonding in the service panel
- Main bonding jumper. Grounding and neutral bus bars should be bonded together (only in the service panel, not in sub-panels);
Common methods that directly tie the bus bars are:
- Tie bar;
- Bonding jumper (if conductor, no smaller than GEC)
Common methods that bond the bus bars by connecting them to the back wall of the cabinet are
- Bonding straps;
- Bonding screws (green); or
- Mounting bus bars directly to the back wall of the cabinet.
Acceptable Bonding Connectors
- Conductors (adequate size);
- Threaded couplings and hubs;
- Threadless (compression) connectors;
- Bonding locknuts, bushings and wedges. (will have screw);
- Standard locknuts
Bonding outside the service panel.
Any metal components that contain current-carrying conductors should be bonded both to each other, and to the grounded (neutral) service conductor. Some jurisdictions may not allow bonding of gas pipes. Components commonly bonded are:
- electrical mast;
- meter housing;
- metal conduit;
- any metal raceways grounded (neutral) service conductor;
- Components that may accidentally become energized should be bonded to the rest of the electrical system:
i. metal water and gas pipes. Look for bonding at water heaters, and at points where pipes pass near the service panel or a sub-panel.
Note: In sub-panels, neutral bus bars must float, i.e., must not be bonded to the cabinet or grounding bus bar. Check to see that green-colored bonding screws have been removed/backed out or that other methods have been used to ensure isolation.
Bonding In Sub-Panels
- Floating neutral bus bar. Neutral bus bar must not be bonded to the cabinet or grounding bus bar.
- No fused neutrals.
Grounding/Bonding Requirements at Separate Structures
- Separate structures having more than one circuit should have their own grounding system (GEC and electrode).
- Electrical panels in separate buildings are sub-panels, the equipment grounding conductor (EGC; also known as the neutral conductor) should float (be electrically isolated from the panel and grounding components).
- Separate structures should have their own means for disconnecting circuits. The disconnect must be rated as service equipment except for garages and outbuildings.
- Identify wiring type;
- Conductor length should not be excessive;
- Look for damage (nicks) to bare conductors where insulation was stripped for attachment to breakers and bus bars;
- If conductors are bent to 90 degree angles, look for broken insulation at the outsides of bends;
- Comment on loose or disconnected wires;
- Aluminum conductors should have anti-oxidant applied at connections and in older homes connections should be tightened periodically. Most common in homes built 1967-1973;
- Discoloration or flaking of insulation indicates overheating;
- Pitting at connections indicates arcing.
- Comment on any backup generator wiring
- Signs of overheating;
- Multiple conductors at connections made for one conductor;
- Improper brands/types;
- Note presence (or lack of) and proper location of GFCI/AFCI breakers for circuits serving:
- Kitchen counters;
- Home exterior;
- Garage (one exception for freezer, labeled)
- Unfinished basement;
- Within 20 ft; of swimming pools or outdoor hot tubs;
- More than 5 ft. and less than 10 ft. from indoor hot tubs;
- Swimming pool cover motors; and
- Jaccuzi tubs.
GFCI will operate properly without an equipment ground! Recommend GFCI protection for houses with ungrounded electrical systems.
Depending on the age and manufacturer, you will see different information on the label. Photograph the label, especially the parts with amperage rating and bonding diagrams. Here is the information you will look for:
The amperage rating of the panel. This rating must not be less than that of the main disconnect. This is the most important information on any label.
The type of panel. This is a number code that corresponds to the locations in which the panel is designed to be installed (interior, exterior, raintight, rain resistant, rain protected, etc.)
- Type 1, rated for indoor use primarily to provide a degree of protection against limited amounts of falling dirt.
- Type 3R, rated for outdoor use primarily to provide a degree of protection against rain, sleet and damage from external ice formation.
- Type 3S, rated for outdoor use primarily to provide a degree of protection against windblown dust, rain and sleet; external mechanisms remain operable while ice-laden.
- Type 4, rated for indoor or outdoor use primarily to provide a degree of protection against splashing water, windblown dust and rain, hose-directed water, and damage from external ice formation.
- Type 4X, rated for indoor or outdoor use primarily to provide a degree of protection against splashing water, corrosion, windblown dust and rain, hose-directed water, and damage from external ice formation.
- Type 6, rated for indoor or outdoor use primarily to provide a degree of protection against hose-directed water, the entry of water during occasional temporary submersion at a limited depth, and damage from external ice formation.
- Type 12, rated for indoor use primarily to provide a degree of protection against circulating dust and falling dirt.
- Type 12K, rated for indoor use primarily to provide a degree of protection against circulating dust, falling dirt and dripping non-corrosive liquids.
- Type 13, rated for indoor use primarily to provide a degree of protection against dust and spraying of water, oil and non-corrosive coolants.
Grounding and bonding diagram- important in identifying the bonding screw.
The listing agency certifying that the equipment complies with manufacturing standards, typically ANCE, UL, or may be both.
Whether it is designed as service equipment or a distribution panel
The number of phases and voltage for which it as designed- typically single phase 120/240
The number of circuits it is designed to contain. This means full size circuit breakers. This number may be improperly exceeded if duplex, triplex or quadplex breakers are used. Lighting and appliance branch- circuit panelboards (for definition, see Types of Enclosures in INSPECTOR REFERENCE of ELECTRICAL SYSTEM) are allowed a maximum of 42 poles. That’s 42 switch handles.
The maximum overcurrent device short circuit voltage- typically 10,000v.
- Amperage rating defects, especially between:
- Service Entrance conductors
- Main disconnect
- Load center
- Non-compliance with listed information
The Circuit Directory should be in place, legible, and accurate. If it looks older than the electrical work you see, recommend confirmation.
- Check for mis-wired receptacles. For more accurate readings use a SureTest or other more advanced testing device instead of a $12 tester.
- Check for outlets installed above electric baseboard heaters.
- Comment on many receptacles installed upside down.
- Comment on lack of GFCI or AFCI protection.
- Comment on GFCI- or AFCI- protected receptacles that don’t respond or respond poorly to testing.
- Comment on missing cover plates.
- Comment on scorched or damaged receptacles or switches.
- Comment on inoperable or weakly operating switches.
- Comment on inoperable or intermittently-operating lights
- Comment on improperly-terminated wires. Just because they don’t carry current when you test doesn’t mean there isn’t a switch somewhere.
- Comment on improper conductor types like Romex used outside the home.
- Comment on antiquated wiring like cloth-covered or Knob & Tube.
- Comment on garbage disposal wiring run through kitchen cabinets.
- Comment on improper garbage disposal wiring (dedicated 20-amp circuit, hardwired or factory cord, splices must be in junction boxes with covers).
- Comment on conductors exposed to potential damage from impact or abrasion.
- Comment on extension cords used as permanent wiring.
- Note: The information provided here is general in nature, requirements vary among jurisdictions. You should take the time to edit this information to ensure that it is accurate for the areas in which you inspect.