JOURNEYMAN LINEMAN EXAM REVIEW
QUESTIONS WITH ACCURATE SOLUTIONS
2026
▶ Why are relays used on OCB controls?. Answer: To sense overcurrent
and trip OCB's
▶ High side fuses are ordinarily from 200 to 300% of full load current of
transformers, if short circuit capacity will permit. What size fuse will be
needed for a 66 KV, 1500KVA at 300%. Answer: 66000/1.732=38106
1500/3=500 KVA. or
500,000 KV
500,000/38106= 13.1
13.1 x 300% = 39.3 or
40amp fuse
▶ Show how to calculate the proper tap to deliver 7620 volts from a
66000/12470Y transformer. Answer: 12470/1.732=7199.7 or 7200
420/7200=5% from 100=95%
66000 x .95 = 62700.
Use a chart to change accordingly.
▶
QUESTIONS WITH ACCURATE SOLUTIONS
2026
▶ Why are relays used on OCB controls?. Answer: To sense overcurrent
and trip OCB's
▶ High side fuses are ordinarily from 200 to 300% of full load current of
transformers, if short circuit capacity will permit. What size fuse will be
needed for a 66 KV, 1500KVA at 300%. Answer: 66000/1.732=38106
1500/3=500 KVA. or
500,000 KV
500,000/38106= 13.1
13.1 x 300% = 39.3 or
40amp fuse
▶ Show how to calculate the proper tap to deliver 7620 volts from a
66000/12470Y transformer. Answer: 12470/1.732=7199.7 or 7200
420/7200=5% from 100=95%
66000 x .95 = 62700.
Use a chart to change accordingly.
▶
