Home Inspection · Electrical Installation Checkup · What To Expect

Considering how much we rely on it on a daily basis, the electrical installation is one of our main focuses while inspecting a house. The tools used for a correct and quick diagnose are the professional Amprobe INSP-3 Wiring Inspection Tester and the FLIR E6 Thermographic Camera.

AMPROBE INSP-3 Wiring Inspection Tester

Properly sized cables, good connections and good ground are the backbone of any residential electrical system. We’ll test for:
  • Voltage drop under load
  • Grounding system quality
  • Faulty GFCI (if installed)
  • Overloaded circuit
Sounds like Gibberish? Let' see:

Voltage under load This is the actual voltage available at the plug in receptacle when a steady load is applied to the line. Anything between 110 and 125 volts will be all right. Voltage drop occurs any time electricity travels through a wire. If the wire is not the right size, or the circuit run is long, the voltage will drop significantly from one end to the other.
When selecting the wire needed for a circuit, size makes a BIG difference. If the conductor is undersized, it creates voltage drop - this can shorten the life of your equipment and waste energy.
The US National Electrical Code recommends no more than a 5% voltage drop. Possible problems creating excessive voltage drop:
  • Loose screw termination
  • Undersized wiring
  • Loose connection at circuit breaker
  • Corroded connections
Grounding system quality The goal of any grounding system is to provide a low impedance path for electrical faults or transient currents to the earth. The effectiveness of a grounding system is determined by the impedance this connection provides to the earth.
A typical rule of thumb is that ground resistance should be less than 25 ohms. Loose connection, splices or undersized ground conductor can cause high impedance.

A Ground Fault Circuit Interrupter (GFCI) is a special socket that can prevent electrocution. In case of a home appliance failure, electricity will always find a path to the ground through a dedicated grounding circuit if available, if not... through our bodies. A GFCI senses the current going in and out. What does this mean? Current goes into the appliance through the black cable and comes out through the white cable. If we have the same amount of electricity going in and coming out, the GFCI will sense that everything is in working order. When the GFCI senses there is less current coming out than goes in, it will trip. These outlets react at extremely small amounts of electricity (even 4 or 5 milliamps) and they do so extremely fast, less than one tenth of a second. When we get electrocuted we divert some electric energy through our body, thus the GFCI will sense something is out of balance and will immediately stop the flow of electricity and save our lives. The GFCI receptacle will provide service like a regular socket even if it's electronic part responsible for protecting us is damaged and stopped functioning. That's why it needs to be regularly checked.

Overloaded circuit This happens when an electrical cable is used for more amperage than it can handle. A 14 gauge wire can safely carry 15 amps and is ideally protected by a 15 amps breaker. If you have a 20 amps breaker on this wire, the breaker and the wire will start to heat if you have excessive draw of electricity on this particular circuit. This is why it's so important to properly size and design an electrical installation.
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