Browsing articles in "Field Reports Blog"

Faulty receptacle grounding

May 10, 2011   //   by Robert Monk   //   Field Reports Blog, Trouble & Repairs blog  //  No Comments

Grounded receptacles require proper wiring methods and proper implementation of those methods, including compression wire nuts that chemically bond wires to each other, rather than wires just twisted together.

Electrical continuity for power wiring in buildings requires bonding conductors wherever continuity relies on more than one piece of conductor (wire). Bonding involves a chemical bond between separate pieces of conductor that will carry current.

Improper bonding of equipment grounding conductors in a receptacle wire box.

In this photo, the installer has used a common shortcut that may provide adequate grounding immediately upon completion of the job, but which will degrade over time, due to oxidation of the outer surface of the copper equipment grounding conductors. For copper EGC’s, oxidation only occurs on the outer surface of the copper. By creating a proper bond at the time of installation, oxidation cannot penetrate and interrupt the bond over time. Read more >>

Consequences of over-lamping

Apr 30, 2011   //   by Robert Monk   //   Field Reports Blog, Reasons to do it right, Trouble & Repairs blog  //  No Comments

Close-up of an A19 lamp holder screw-shell, with outer insulation cracked from overheating.

Few lampholder sockets, except for outdoor fixtures or three-position floor lamps, are rated to accommodate the all-too-common 100W incandescent light bulb (lamp).

This photo shows what happens over time, if you use 100W incandescent lamps in the wrong fixtures (most of which are rated 60W or 75W maximum). Incandescent lamps are being replaced by CFL’s and LED’s because 90% of the energy they consume is invisible heat radiation. The heat destroys lamp holder screw-shell sockets and the wires leading to them.

In the photo, the insulation around the screw-shell has become brittle from baking by the 100W lamp. The screw-shell itself makes electrical contact via rivets at the base, which is cheap aluminum and has also baked its way loose of the rivets. The result is a familiar problem in old houses with old fixtures: a slowly-worsening problem of lamp flicker and intermittent lamp failure. The intermittent, poor contact at the loose rivets can generate heat from arcing at the connection, and could ignite wires and start a fire. Read more >>

Why do rodents chew wires?

Apr 29, 2011   //   by Robert Monk   //   Field Reports Blog, Reasons to do it right, Trouble & Repairs blog  //  No Comments

I have found that chewed cables tend to be the ones that were not properly strapped along solid supports. It’s widely reported that rodent’s teeth never stop growing, and therefore require constant grinding to keep them from growing long enough to ‘hamper the hamster’. But why do they chew wires that could kill them?

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Panel bonding jumper missing / 200A Service

Apr 27, 2011   //   by Robert Monk   //   Field Reports Blog, Trouble & Repairs blog  //  No Comments

A green-colored screw should thread into the heavy gauge steel of this 200A service panel enclosure, securing the bonding jumper. At the center of the highlighted area in the photo, one can see that the screw was either removed or never installed.

20110427-025141.jpg

 

This threaded ground bonding location ensures that the metal panel enclosure remains at zero voltage to the building and service grounding systems, and helps ensure that a low-impedance path for fault current on the panel enclosure will trip a breaker before serious damage occurs. A poor connection here could result in a high-impedance path for fault current. An ungrounded (‘hot’) conductor could contact the panel enclosure and discharge to ground through this poor connection at relatively low levels of current not sufficient to trip the breaker protecting the circuit. At least two hazards would result:

  1. The connection missing the screw could heat up and melt adjacent wire insulation, causing more trouble, or ignite the wooden surface on which the panel is mounted.
  2. The panel enclosure would remain energized until the fault is cleared, and could electrocute someone.

 

Frayed service cable / power quality

Apr 26, 2011   //   by Robert Monk   //   CUSTOMER RESOURCE BLOG, Electric 101 Blog, Field Reports Blog, Trouble & Repairs blog  //  No Comments

What are you looking for?

If you can see exposed aluminum strands on your service entrance cable, it has frayed to the point where you should replace it. Cost may vary from $750 – $2200, depending on your service capacity (usually between 100A – 200A) and the capacity of your replacement service (for those wanting central air conditioning, an upgrade from 100A to 150A or 200A will often be needed; subsequent solar PV or micro wind power installations over 5kW capacity may be cheaper to install if the existing service is larger than 100A).

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Fuse cabinet as distribution panel

Apr 22, 2011   //   by Robert Monk   //   CUSTOMER RESOURCE BLOG, Electric 101 Blog, Field Reports Blog, Trouble & Repairs blog  //  No Comments

Many homes in West Philadelphia feature a distribution panel remote from the main service equipment. In older installations, this may be a wooden cabinet with a picture-framed wooden or glass-pane door, usually located in a stair- or hallway, and lined with a felt-like friable material that may be asbestos.

Several fuse-holder modules provide for branch circuit over-current protection. Unlike with modern wiring, the fuses may protect both the grounded (neutral) and ungrounded (‘hot’) conductors of 120V circuits, so a single circuit may have two fuses in it.

 

These fuse cabinets may not meet the demands of modern electrical usage

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CFL’s are good, but not great

Apr 15, 2011   //   by Robert Monk   //   CUSTOMER RESOURCE BLOG, Field Reports Blog, New in electricity..., Smart Energy Blog  //  1 Comment

First, let me say that I recommend using CFL’s. It’s just that I wonder if mandating conversion from incandescents to new lighting technologies shouldn’t be coupled with some better education about the new lamps.

Soon to be mandated to exclusion of incandescents, are CFL’s as good as people make them out to be? CFL’s have several under-publicized issues that all customers should be aware of.

Read more >>

AFCI’s, cost, and fire-safety

Apr 15, 2011   //   by Robert Monk   //   Field Reports Blog, Reasons to do it right  //  No Comments

An excellent video on YouTube details the function, costs, and fire-prevention advantages of Arc Fault Circuit Interrupters (AFCI’s).

 

Electrical System Review 20110127_S49th

Apr 11, 2011   //   by Robert Monk   //   Field Reports Blog  //  No Comments

xxxx S 49th St., Philadelphia, PA

Inspection conducted January 27, 2011 pursuant to settlement contingencies in the sale of a home

by

Robert Monk

Robert Monk Electric

Philadelphia Lic. #35849

PA HIC #060608

CONTENTS

I     SUMMARY

II   SCOPE OF REVIEW

III  ITEM DETAILS

IV  PROPOSALS & ESTIMATES

V   CONTINGENCY FOR CERTIFICATION TO INSURER

VI  PHOTOS

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Electrical System Review 20110330_S49th

Apr 4, 2011   //   by Robert Monk   //   CUSTOMER RESOURCE BLOG, Field Reports Blog  //  No Comments

Following is copied from a formal presentation resulting from by-the-way observations during a service call for a single branch circuit outage…

CONTENTS

  1. Summary

  2. Scope of Review

  3. Item Details & Recommendations w/ Estimates

  4. Illustrations

 

I SUMMARY

The electrical system needs a 2-year program of gradual upgrade and repair that might cost between $1000 and $5000. The basement ceiling is a rat’s nest and the service equipment has been incompletely consolidated from four (4) 60A services to one (1) 60A service currently in use plus another that is energized but not in use. With multiple adults in the large building, the service should be 100A minimum; two 60A services would be more than enough, if loads were balanced across them, but this involves an ‘overhead’ of an additional $5/month to maintain unneeded separate billing for the two metered accounts. A single, 100- , 150- or 200A service would be ideal for the current use, but would involve higher up-front costs.

Service entrance cables from the abandoned meters have been disconnected inside the multi-gang meters enclosure, but remain a hazard because of their proximity inside the enclosure to live terminals that have no over-current protection (breaker or fuse). These should be removed or terminated in proper enclosures, as part of any work to complete the electrical service equipment.

Other specific electrical problems I observed in this building include: open wire enclosures in basement ceiling and 2nd floor switch box. Abandoned receptacle location at Dining Room north, NM-B (“Romex”) cable subject to damage where run loose in attic, frayed cables in basement ceiling, rusted conduit at Exterior north, near service meters, missing GFCI protection at Basement laundry area, missing bushing where service drop cable at Exterior north exits protective sleeve conduit, and some non-electrical wood rotted on Exterior north window trim and siding.

Also, the basement has a damp floor and smells strongly of mold.

Read more >>

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