Page 55 - Apprentice Manual_Neat

138. Which is NOT a transfer switch operator mechanism?

a. Motor
b. Linear motor
c. Hydraulic cylinder
d. Solenoid

139. How should a transfer switch operate if the utility power is available, it is currently supplying
generator power, and the generator fails?

a. Transfer back to utility
b. Stay on generator source in case it is restarted
c. Drop to a neutral position in order not to back-feed either system
d. Transfer back to utility, but continue to sense for generator restart

140. Closed transition of a switch means what?

a. Break-before-make
b. Make-before-break
c. The switch must close before current may be passed
d. Any open contacts must be closed before generator start-up to prevent arcing

141. A transfer switch will:

a. Not send a start signal to the engine
b. Prevent the generator from shutting down
c. Switch to its preferred source position when power is available
d. Transfer to a secondary source even when the secondary is not available

142. Regarding over-current faults, transfer switches are designed to:

a. Transfer the fault
b. Isolate the fault and continue to provide power to the other circuits
c. Repeatedly switch between sources
d. Withstand the fault

143. A time delay is used for what purpose in transfer switches?

a. To allow electric motors to completely wind down before restart to prevent damage
b. To prevent continuous cycling between sources during brief outages
c. To allow the generator time to warm-up before applying full load
d. Time delays are not used in transfer switches, this could cause damage to devices that
cannot be without power

Page 47 - EGSA Apprentice Certification Program Study Guide