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2nd Step SSQs Questions with correct Answers
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Exam of 10 pages for the course SAFe APM at SAFe APM (2nd Step SSQs)
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2nd Step SSQsAccording to the APM, what size and type of rope is required for lowering a person from
a pole? - answer Rope with a safe workload rating equal to approved 1/2 inch handline
material shall be used when lowering a person from a pole or elevated position.
What are the basic steps in pole top rescue? - answer1. Clear victim of imminent
danger
2. Administer first aid
3. Lower the victim to the ground
What is the purpose of a breakaway reel? - answerThis reel is designed to recover
overhead, as well as underground conductors that are to be salvaged.
What are the maximum fault duties for the 3 sizes of grounds used on distribution
voltages? - answer#2=9,000A
2/0=18,000A
4/0=30,000A
What size grounds should be used on 1/0 ACSR circuit with a fault duty of 10,000 A? -
answerFor aluminum conductors 1/0 AWG or smaller, then #2 AWG copper grounds
may be used for grounding, regardless of source voltage and fault current duty.
How does a lineman find the fault duty for a particular circuit? - answerRefer to the
Protection Engineering website
How often is grounding equipment tested? - answerEvery 2 years, through GARP
Under what circumstance is it required that the substation ground grid be used as the
grounding medium? - answerThe sub ground grid shall be used as a ground medium
when grounding within 40 feet of the sub ground grid and proper locations shall be
selected for routing and attaching grounds to the sub ground grid.
What size conductors are typically used in single-phase lighting secondaries? -
answerCertain sizes of conductors are most commonly used for lighting secondaries:
1/0 aluminum or #2 copper in all residential areas except those designed for min
service, and 4/0 or 2/0 copper where the initial installation requires transformers larger
than 25kVA
The APM prescribes two safety guidelines that must be performed prior to working on a
transformer with banked secondaries. What are they? - answerWhere secondaries of a
transformer are banked or there is a possibility of backfeed the transformer secondary
, leads shall be disconnected in a addition to pulling primary fuses before any work is
done on a transformer.
What are the min acceptable Megger test values for accepting both new and old
transformers, prior to installation? - answerNew:>999
Old:>500
Why are Megger checks performed on tranformers? - answerThe Megger measures the
effectiveness of a transformer's electrical insulation.
What is special about Megger and TTR tests on 6.9kV/9.5kV(Ø-Ground) 240/120 V,
non-fused, single-phase BURD transformers with three low-voltage bushings? -
answerNo Megger test is possible since both windings and the tank are all connected.
List two examples of transformer defects that may be detected with TTR and Megger
checks. - answerA transformer can become defective in several ways. Broken insulation
or shifting components can lead to shorts either within windings or between leads and
the case or between windings and the core. Any one of the many connections inside the
transformer can open up due to improper crimping or brazing or improperly secured
fasteners. Leads may be routed incorrectly during the assembly process resulting in
incorrect polarity. Each of the defects just described may be detected using the Megger
and TTR.
What five precautions must be observed before and/or during Megger testing of a
transformer? - answer1. Isolate the transformer
2. Watch out for shocks
3. Make a good electrical contact with the terminals
4. Vent the transformer
5. Understand the transformer nameplate
Why are TTR checks performed on distribution transformers, prior to installation? -
answerThe function of this meter is to identify defects that would show up as anomalies
in the turns ratio of the transformer.
Describe what a transformer's polarity is. - answerThe relative instantaneous direction
of current through the coils of a transformer.
What is the max acceptable level of error (percentage) when performing a TTR check
on a transformer? - answer0.5%
What is the purpose of a tap changer? How does it work? - answerTap changers allow
the transformer to be "fine tuned" so that the output of the transformer remains at the
rated low voltage despite a higher or lower system voltage. This "fine tuning" is
accomplished by increasing or decreasing the effective number of turns in the high-
voltage winding.
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