What are Daisy Chained & Back-Stabbed Receptacles?

Daisy chaining is the practice of running wires from receptacle to receptacles via either back-stabbing (sticking the wires in holes in the back of the receptacle—left of picture)  or using the screws on the side of the receptacle (center of picture).

(could be switches as well but for now we will discuss receptacles)

This is a poor practice, especially the back-stabbing approach, as every connection can result in voltage drop such that by the time you get to the end of the circuit the voltage drop affects the function of whatever is plugged in. 

The side screw type daisy chain is not quite as problematic but with that method if something goes wrong with one receptacle it would affect any others downstream from the problem one.

Different ways to wire a receptacle

A better practice is to wire-nut the wires together in the box, and then run a pigtail to the receptacle (right side of picture)—doing this for the ground wire, the “white” (neutral) wire and the “black” (hot) wire (sometimes the colors vary for the hot conductor).

The pigtail method is considered “best practice” but is obviously more labor intensive and therefor more expensive to have done.

Better modern receptacles also have plates with screws where the wires insert without bending and are tightened behind plates under the screw–this should not be confused with back-stabbing. 

With back-stabbing there is a sharp upward sloping barb that prevents the wire from pulling out and this is the entire connection–the amount that sharp barb grabs onto the wire.  This type of connection is especially problematic with aluminum wiring.

By Charles Buell, Real Estate Inspections in Seattle

If you enjoyed this post, and would like to get notices of new posts to my blog, please subscribe via email in the little box to the right. I promise NO spamming of your email! 🙂

What is that dang bare copper or aluminum or green ground-wire for anyway?

The grounding/bonding wire.

This poor wire is a bit schizophrenic.  It has different names depending on where it is terminated and many people accuse it of doing things it is not responsible for. 

dscf7009For example when we run this wire to our house grounding electrode system (ground rods, Ufer grounds, metal water pipe etc) we call it a GEC, or Grounding Electrode Conductor.  When we run it from switches, receptacles, lights and other points of use to our electrical panels we call it an EGC, or Equipment Grounding Conductor.  The two uses are tied together as if they were “one” in your electrical service equipment (your main panel). 

This leads to considerable confusion over what it actually “does.”

In simplistic terms, the GEC (grounding electrode conductor) is a path to dissipate static charges and surges safely back to the earth via the ground rods, Ufer ground, or metal water pipe it is attached to.

The EGC (equipment grounding conductor) serves two functions:

  1. It provides an effective ground fault current path to trip a breaker or blow a fuse in the event that there is a short to the metal components being bonded.
  2. It provides a path to earth to dissipate static charges and surges that would otherwise build up on the electrical system.

There is a myth that is pervasive among home inspectors, and even some electricians, that the equipment grounding conductor is there to prevent shock.  There is another even more serious myth that all electricity is trying to go back to earth and this is how it gets there.  It is really best to forget both of these myths if one is to stay safe.

The reason for the confusion is that if there is a “short” to the grounded metal components and the circuit is tripped off, one obviously can’t get a shock from something that is turned off.  The dangerous aspect of this is that the metal components can be energized up to the amperage of the circuit (and even beyond) without tripping the breaker and a person touching the metal components would still get a shock.

If the person happened to be touching the grounded metal component at the very time the fault occurred, they could still get a shock–albeit a very short one.  It still could be enough to arrest one’s heart or scare one off a ladder resulting in possible serious injury.  So in this respect the equipment grounding conductor is not a true shock protection component of the system.

Obviously with no ground wire at all we have no chance of shutting of the equipment in the event of a short and we do actually increase the chance of getting shocked.  The solution is not just to install the ground wire–because that will only improve the situation–not eliminate the risk.

To reduce the risk of shock we must install GFCI protective devices, either as receptacles at points of use or as circuit breakers that protect the whole circuit.  We do not even need a ground wire to gain this protection.  The GFCI devices do not need a ground to function and this is why they are so important and valuable on older homes without equipment grounds until the systems can be upgraded.

The most critical thing to remember when you are working around live wires is as long as you do not contact grounded metal components and are physically isolated from the actual earth (not standing barefoot on concrete or kneeling on the wet ground) you have pretty much zero chance of getting a shock when you touch an energized component.  Of course if you touch the neutral and hot wires you will indeed get a shock.  Because we might make a mistake or not realize when we are grounding ourselves, we install GFCI devices to take care of us.

It is best practice to never assume metal components are not energized.

By Charles Buell, Real Estate Inspections in Seattle

If you enjoyed this post, and would like to get notices of new posts to my blog, please subscribe via email in the little box to the right. I promise NO spamming of your email! 🙂

Here’s mud in your eye!

I have slung more drywall mud in my life than I care to think about. My messed-up shoulders will attest to that. I am quite sure that the amount of the goop I have spread around with a trowel is in the thousands if not tens of thousands of gallons. I have spent many hours clunking around on stilts. In fact, I was on stilts when the wave of the 2001 Nisqually earthquake moved through the house I was working on. When I got out of the house the telephone poles and wires were still waving. I had gotten pretty comfortable going up and down stairs on stilts.

One of the things you learn pretty quickly about drywall mud is that it takes forever to dry if it is installed too thick–especially if the weather is humid. Building up successive thin layers creates a much better job than trying to push-the-river with too much material.

Generally when you needed to do a heavy fill you would mix up some of the stuff with a quicker set time. Silverset was one of my favorite types because it sanded pretty easily when dry–unlike some of the other brands that set up more like concrete. In the early days of my drywalling career there was only stuff that set up so hard you could barely sand it.

After discovering the light-weight products, we used to call “mud-lite,” life became much easier. There was Silverset 20, Silverset 40 and Silverset 90. The numbers referred to the number of minutes you had to work with the material before it solidified in your bucket–and several times I got to experience the reality of these numbers.

Everyone remembers fooling around with Plaster of Paris–well these fast setting joint compounds are a bit like that–just not nearly as hard when set.

I had a flash back at an inspection and my shoulder understandably started to hurt.

mud-light

Mud Light

Someone could have benefited from knowing about Silverset 90–and a little bit better understanding of electricity might have been advisable as well.

Perhaps this was just their version of “mud-light.”

By Charles Buell, Real Estate Inspections in Seattle

If you enjoyed this post, and would like to get notices of new posts to my blog, please subscribe via email in the little box to the right. I promise NO spamming of your email! 🙂