It’s essential that electrical circuits are safe. This means that the wiring must be up to specification and circuits properly grounded. Unfortunately, this is not always the case, and electrical circuits that might otherwise appear sound, may be faulty and dangerous. Since it is almost impossible to check and trace every circuit because wiring is partially hidden inside conduits, wall spaces and inaccessible roof spaces, a straightforward method of testing circuit integrity is needed. This is where Tasco’s Inspector II™ electrical installation tester comes into its own. It allows you to check circuit integrity without the need to physically trace wiring or dismantle sockets.
NEC Wiring Requirements
The NFPA 70 National Electric Code (NEC) governs electrical installations, and although it’s beyond the scope of this article to explain it in detail, it’s essential that electrical circuits comply with NEC recommendations. Among its recommendations, the NEC specifies that wiring must be adequately sized for the load and that the voltage drop at socket outlets should be no more than 5 percent at the rated current of the circuit. Apart from this, all three-pin socket outlets must be properly grounded to prevent shock. Also, circuits that are located near water, such as those in bathrooms and kitchens, must be protected by ground-fault circuit interrupters (GFCI).
Checking Wiring Safety Using Inspector II
Taco’s Inspector II is designed to test the safety and condition of two- and three-pin 120 Volt AC socket outlets rated for 10, 15 and 20 amps, including those protected by a ground-fault circuit interrupter. The tester is simply plugged into the socket and it simulates an electrical load at the socket outlet. Because the tester only draws a small load on the circuit and uses internal logic to calculate the voltage drop and other measurements, circuits and circuit breakers are not stressed unnecessarily. The tester’s bright LEDs display the state of the circuit. Using Inspector II, you can perform five critical tests on each circuit in a matter of minutes:
- Measuring volt drop: The tester is plugged into the socket outlet, and using the multi-position switch, the maximum load current is selected. The tester simulates the load and the device calculates the voltage drop at that load. If the volt drop is less than 5 percent and the supply voltage under load is within specification, the green LEDs light up indicating the circuit is sound. However, if the voltage drop exceeds 5 percent, red LEDs indicate there is a problem in that circuit. Reasons for wiring problems include inadequate wiring, faulty splices and bad connections that could overheat and potentially cause a fire.
- Checking socket wiring: Inspector II performs a test on each socket that checks for wiring polarity. If the H/N Rev LED comes on, the hot and neutral wires have been swopped. When this happens, it’s possible the hot and ground wires are also incorrect and the H/G Rev LED will illuminate. Finally, if the ground or neutral wires are not connected the Open GndNeut light comes on.
- Testing ground impedance: The Inspector II ground resistance test measures the resistance to ground at the socket. If it’s greater than 2 ohms, the red LED lights up showing that the ground connection is poor and needs to be repaired. As a safety precaution, if the ground resistance is less than 0.02 ohms, the yellow LED comes on as a warning that such a low resistance indicates a possible short to the neutral conductor. The green LEDs confirm the ground impedance is within specification.
- Checking ground fault circuit interrupters (GFCI): The GFCI is designed to disconnect the power the moment a high resistance earth fault is detected. This important safety device provides protection against electric shock, especially near water, where the consequences of inadvertent contact with a live conductor, when wet, could be fatal. The GFCI test injects a current to ground of 6.8 milliamps to test the GFCI breaker, which should immediately trip.
- Testing two wire ungrounded outlets: Older installations may have two wire ungrounded outlets. These can be tested using a high-quality three-to-two pin adaptor to connect to the two-pin socket. Naturally, the ground impedance test cannot be performed and neither can the polarity test be done. However, the on-load voltage drop test can be performed.
Inspector II is suitable for use on 120 volt circuits; it is not rated for, nor capable of testing 240 volts sockets, and could be damaged if a test at this voltage is attempted. It is also not possible to test the integrity of the wiring insulation because this requires a specialized insulation tester capable of generating a high test voltage.
Preventing Call Backs
The Inspector II is a great tool for checking that new installation work and repair work has been done correctly and that there are no hidden wiring faults such as poor connections or splices. Simply plugging the tester into each socket outlet allows you to test, almost instantaneously, each circuit to ensure the wring is the right size and that there are no other faults. Inspector II avoids call backs and ensures satisfied customers.
Home and Commercial Inspections
Inspector II is a great tool for 120V wiring inspections because it allows inspectors to quickly and accurately check wiring circuits throughout the electrical system simply by plugging the tester into each socket. Apart from it being quick and easy, Inspector II provides home inspectors with a unique tool that really checks the condition of the wiring to electrical sockets without the need to remove cover plates or outlets.
Inspector II: Fast and Easy Wiring Verification
Using the Inspector II, it’s possible to quickly yet accurately check the volt drop, ground resistance and polarity of 120 volt socket outlets. This is a great way to ensure installation work has been performed correctly and, for existing installations, it provides peace of mind that all is well. It saves time and money and eliminates the need for guess work. Reduce call-backs, save time and avoid unhappy customers by always using the Inspector II to check circuits before and after every job!