Patent ID: 7061248
Filing Date: 2006-06-13
Classification: G01R

Abstract:
1. An improved portable electrical utility service tester, for troubleshooting a 120/208 or 120/240, three phase or single phase alternating current electrical utility service where 120 volt hot leg leads of the electrical utility service are connected 120 volts to ground only; the tester being powered by the electrical utility service being tested, the tester comprising: electrical test circuitry and a case for containing the electrical test circuitry; the electrical test circuitry having a left hot lead for connecting the tester to a left hot leg of a service being tested, a right hot lead for connecting the tester to a right hot leg of a service being tested, and a neutral lead for connecting the tester to a neutral leg of a service being tested; the electrical test circuitry including a first test circuitry for indicating, upon a connection of the tester hot and neutral leads to the corresponding hot and neutral legs of a service being tested, whether or not the left and right hot legs of a service being tested are shorted together and whether or not a service being tested is providing at least of total of 130 to 135 volts of power; the first test circuitry having a light which is lit only when the left and right hot legs of a service being tested are not shorted and a service being tested is providing at least a total of 130 to 135 volts of power; the electrical test circuitry including a second test circuitry for indicating potential difference between the left hot leg and the neutral leg of a service being tested which includes a left hot leg to neutral leg voltmeter for providing a reading of the potential difference between the left hot leg and the neutral leg of a service being tested; the electrical test circuitry including a third test circuitry for indicating potential difference between the right hot leg and the neutral leg of a service being tested which includes a right hot leg to neural leg voltmeter for providing a reading of the potential difference between the right hot leg and the neutral leg of a service being tested; a left hot lead control switch which must be manually actuated for turning on the second test circuitry, a right hot lead control switch which must be manually actuated for turning on the third test circuitry, and a test off switch; the left hot lead control switch, the right hot lead control switch, and the test off control switch being interconnected by circuitry whereby once the second test circuitry has been turned on by a manual actuation of the left hot lead control switch, the test off control switch must be manually actuated before the right hot lead control switch can be manually actuated for turning on the third test circuitry and once the third test circuitry has been turned on by a manually actuation of the right hot lead control switch, the test off control switch must be manually actuated before the left hot lead control switch can be manually actuated for turning on the second test circuitry; and the second test circuitry having a timer means therein for imposing a time delay in completing activation of the second test circuitry by delaying a closing of a relay switch in the second test circuitry connecting the second test circuitry directly to the left hot lead of the electrical test circuitry when the left hot lead control switch has been manually actuated and the third test circuitry having a timer means therein for imposing a time delay in completing activation the third test circuitry by delaying a closing of a relay switch in the second test circuitry connecting the third test circuitry directly to the right hot lead of the electrical test circuitry when the right hot lead control switch has been manually actuated whereby time consumed by having to manually actuate the test off switch when turning either the second or third test circuitry off and manually actuate the other of the hot lead control switches when turning either the second or third test circuitry on and the time delay imposed by the timer of the second or third test circuit being turned on prevents having the relays of the second and third test circuitry simultaneously closed to thereby prevent damage to the electrical test circuitry of the tester by preventing the second and third test circuits from being simultaneously operative.