When I inform my clients that they might want to bump up the service to more amperage and a differently-distributed box, I often get the question, "Can you stress your electrical service?"
Why? Often on home inspections I find that the service is underpowered for the load the house will demand, particularly if a family of four or five people will be moving in. And remember, our electrical use increases an average of 7% per year, so, employing the 72 rule, that means our use doubles more or less every 10 years.
Yes, yes you can!
The house in question has more people in it than it should and fewer receptacles than it should. The service of 150amps is minimal for modern use since everything in the house is electric (except for an oil-burning boiler which probably does not work), and there is a lot going on in there!
The panel box in the house has no cover. It was probably upgraded to this box in the early 80s. Some unprofessional people have been in it to make changes. Notice the photo on the right. There is corrosion of the service line (that powdery substance in the hole) and more than one double-tap on the neutral bar on the right. A double tap is when two, or more!(!), white cables are secured by one screw, called a lug.
Since it is not labeled I don't know what corresponds to what.
Almost directly below the box is a sump pump which does not work. Every time it rains water must percolate up out of it because the floor nearby is underwater, as is all the STUFF nearby.
It is plugged into the only receptacle in the basement! As are two power strips, and other things in the basement.
This basement houses, unbelievably, a family with two adults and 2-4 children.
If someone was to touch that aluminum strip under the circuit breakers it would kill them. That outlet is not grounded, as it has only two prongs to plug into. Notice that the black sump pump cable is utilizing and adapter to plug into it because the sump pump demands a grounded, three-prong receptacle. Those power strips service everything electrical in the "apartment." This one receptacle is very overloaded.
Throughout the house, NONE, not one, of the three-prong receptacles was grounded. I could find very few receptacles on the walls because of all the STUFF. The ones that were able to be accessed all looked like the overloaded photo above. This can be very dangerous.
Plugged into these few receptacles were four large-screen TVs and four window air conditioners. They draw a lot of power. There were other things too, like lamps and things, and the normal STUFF people plug in.
Is there stress? And how could we tell? With thermal imaging!
For all I know, those two breakers on the right which are white in color are the two that service all the receptacles. There may be more as there is a little warmth else where. But without labels you can't tell what is what.
Warm temperatures would be orange and yellow. White would be the hottest temperature evident in the thermal image. In this case the hottest spot is 149F.
THAT IS VERY HOT! THAT IS VERY STRESSED!
My recommendation: too much is too much! The entire panel box can be stressed electrically, as can individual circuits. It's very important that the proper number of people are using a proper number of receptacles to get the proper distribution of service throughout the house. If too many people are using too few receptacles, thereby overloading them and the entire circuit, a dangerous situation can result. Also, it is critically important to properly label the panel box circuits so you know what use is where!
How many receptacles are typically serviced by one 15amp breaker? The rule of thumb employed by most electricians is 12, but I have seen more. Often the number is less!
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560