Lesson 3/Learning Event 2
Learning Event 2:
DESCRIBE CONSTRUCTION AND USE OF LOW-VOLTAGE CIRCUIT TESTERS
The military low-voltage circuit tester (LVCT) is a heavy-duty test instrument. When you open the
case, you will see two test meters that you are already familiar with, the ammeter and voltmeter,
but there are some connections and controls not found on the separate ammeter and voltmeter.
Some repairers shy away from the LVCT, but it is really simple to use. Once you learn what each
connection and control is used for, the LVCT will make your troubleshooting problems a lot easier
When you are assigned to a unit that is authorized an LVCT, learn to use it as soon as possible. If
your unit is issued a second LVCT that does not look anything like the first, do not send it back.
The Army now uses several different models of LVCTs with only one Federal stock number
(FSN). This means your unit may order an LVCT under FSN 4910-092-9136 and receive one of
several different testers. All LVCTs include one ammeter and one voltmeter; however, the controls
and connections vary.
The LVCT in your unit could be made by any of the following firms: Auto Test, Inc., Model
10308; Atomic Engineering, Model TV100; Austin Continental Industries, Model 1060/A; Electro
Mechanisms, Inc., Model 1060; Ram Meter, Inc., Model 62F151; Allen Electric and Equipment
Company, Model 30-92; or Futrenics Industries, Inc., Model 225-01. If you tried to learn each of
these LVCTs from one lesson, you would be very confused. However, if you know how to use
one, you easily learn how to use the others by following the instructions. Let's see what the Allen
Model 30-92 LVCT looks like and how to use it.
The Allen Model 30-92 LVCT is a portable (hand carried) test instrument. It is used for testing
low voltage, DC, and electrical circuits on automotive vehicles. The unit includes a voltmeter and
ammeter, to measure voltage and amperage, and a load bank that is an adjustable resistance unit.
The load bank is used for current tests of values up to 100 amperes on a 24-volt circuit.