2-2-14

How much voltage will be available at H1 on a 7,200 to 120/240 transformer if the lead from X1 contacts a wire phase energized at 120 volts? a.3,600 V b.7,200 V c.8,000 V d.8,200 V

A. 3,600v

The use of PCBs in transformer oil was declared a(n) ? by the EPA in the 1970s. a.bio-degradable particle b.environmental hazard c.good coolant element d.non-issue

B. Environmental hazard

The primary voltage and the ? rating of the transformer are two factors that determine the fuse size. a.dielectric b.kilowatt c.kVA d.temperature

C. KVA

Paint discoloration on an overhead transformer may be a sign of ? . a.a permanent fault b.a transient fault c.overheating d.weathering

C. Overheating

Installing a transformer over a hot secondary with the leads installed ? . a.is acceptable as long as the ends of the leads are taped b.saves time c.should never be done d.wastes wire because it is not clear what length is needed

C. Should never be done

A current-limiting fuse in series with the cutout will ? . a.limit the kVA that can be drawn off a transformer b.reduce the number of customers off a transformer c.reduce the risk of back-feed d.reduce the risk of violent transformer failure

D. Reduce the risk of violent transformer failure

A company specifies the ? and ? of a fuse to be used in a transformer. a.length / size b.location / speed c.size / location d.size / speed

D. Size/speed

The ? fuse reduces nuisance fuse blowing due to transients such as lighting. a.fast link b.K-link c.surge link d.T-link

D. T-link

A broken grounding conductor is of no concern if the secondary ground is still in place. Select one: True False

False

A transformer will not back-feed until it is mounted on a pole. Select one: True False

False

An overhead fuse can be closed by hand if the Qualified Electrical Worker is wearing rubber gloves. Select one: True False

False

Back-feed will only occur on a transformer if full secondary voltage is applied from X1 to X3. Select one: True False

False

The current available out of the primary bushings is always twice the secondary current. Select one: True False

False

To energize a transformer, a load-break elbow on an underground transformer should be inserted by hand. Select one: True False

False

When it blows open, the internal primary fuse of a CSP will deenergize everything above it to the main line. Select one: True False

False

A transformer tank may become energized on a single-bushing transformer if the tank is not grounded and a back-feed situation happens. Select one: True False

True

During an outage, a customer's generator can cause back-feed at the transformer. Select one: True False

True

It is not a recommended practice to use a CSP as part of a bank of transformers. Select one: True False

True

OSHA does not require a written job briefing if a worker is working alone. Select one: True False

True

External damage to a transformer tank may include ? . a.a pitted tank, damaged bushings, and an open cutout b.an open cutout, leaking oil, and damage to the bushings c.damaged bushings, leaking oil, and a bulged tank d.damaged bushings, leaking oil, and faulty lightning arresters

c.damaged bushings, leaking oil, and a bulged tank