2-5-10
A megohmmeter test is a nondestructive test. This means that a setting of ? should be used on a secondary cable rated up to ? . Select one: a.500 / 600 V b.600 / 500 V c.1,000 / 600 V d.5,000 / 4,000 V
A. 500/600 V
During a megohmmeter cable test, leakage current can take two forms: current through the insulation, and current ? . Select one: a.along the surface of the insulation b.leakage at the pothead c.leakage into the neutral/ground d.tracking at insulators
A. Along the surface of the insulation
Insulation resistance opposes ? current either through or over the surface of the insulation when voltage is applied. Select one: a.initial b.leakage c.primary d.secondary
B. Leakage
Most megohmmeters are rated at ? DC or higher. Select one: a.600 V b.900 V c.1,000 V d.10,000 V
C. 1,000 V
A megohmmeter uses a high ? voltage to perform an insulation test on a cable. Select one: a.AC b.constant/steady/filtered c.DC d.variable
C. DC
When using a megohmmeter to test a faulted section of cable, before the test is conducted, the cable must be ? . Select one: a.cable prepared to specifications b.checked for current c.grounded to drain any capacitance d.sealed from the environment
C. Grounded to drain any capacitance
When preparing for a megohmmeter test on a section of underground cable, both ends of the concentric neutral must be ? . Select one: a.bonded to the conductor under test b.connected to separate ground rods c.isolated from ground d.tied together
C. Isolated from ground
When calculating the resistance of a circuit, ? Law applies. Select one: a.Kirchhoff's b.Norton's c.Ohm's d.Thevenin's
C. Ohm's
One reason to perform a megohmmeter test would be if there was suspected damage to the insulation by a ? . Select one: a.CT drawing current from the cable b.faulty ground c.related component failure d.solid neutral to ground connection
C. Related component failure
A factor that can cause insulation to degrade is ? . Select one: a.electrical stress b.mechanical stress c.thermal stress d.all of the above
D. All of the above
While performing a megohmmeter cable test, if the meter shows 0, it is probably a ? fault. Select one: a.high-resistant b.low-resistant c.series d.shunt
D. Shunt
A megohmmeter can only be used to test the insulation of cables. Select one: True False
False
A megohmmeter test on a section of faulted underground cable can pinpoint the area of the fault. Select one: True False
False
Megohmmeter tests are extensive; a simple pass/fail test is not available when using a megohmmeter. Select one: True False
False
OSHA 1910.268(o) calls for safe work practices to be in place when doing high-voltage testing. Select one: True False
False
The guard lead from a megohmmeter reads the voltage leakage that might be present when checking a cable. Select one: True False
False
A cable is considered good if it reads one megohm for each kilovolt of cable rating. Select one: True False
True
When performing a time resistance test on a cable, the megohmmeter test usually runs for ? , depending on the meter manufacturer and the voltage applied. Select one: a.1-9 minutes b.1-10 minutes c.5-15 minutes d.6-20 minutes
b. 1-10 minutes
A megohm is equal to ? . Select one: a.100,000 Ω b.250,000 Ω c.500,000 Ω d.1,000,000 Ω
d.1,000,000 Ω
One of the things maintenance testing of cable indicates is the ? . Select one: a.insulation thickness of the cable b.kVA capability of the cable c.presence of water treeing d.remaining life of the cable
d.remaining life of the cable
