Page 91 - Apprentice Manual_Neat

S4-Q96.) A typical battery charger will contain a fuse, a rectifier, and a __________.

a.) Battery
There is no battery inside a battery charger.
b.) Current limiter
Current is limited by the ability of the battery to conduct and the output rating of the transformer and
rectifier. Any current protection will be done by the fuse.
c.) *Transformer
Correct. The transformer is the heart of the battery charger.
d.) Ignition switch
There is no need for an ignition switch in a battery charger. Some boosters may have a remote start
button which is tied to the system ignition.

S4-Q97.) Battery load capacity is usually tested with the use of a battery load tester. If such a device is
unavailable, however, what method may be used to test the cranking capacity of a battery?

a.) There is no other way to test cranking capacity, a load tester must be obtained
Load testers are just a resistive heat element (usually) and can be replaced with other devices capable
of measure current draw and voltage drop while providing a sufficient load.
b.) Observe the cranking speed while starting
This may give indication of battery condition, but is an incomplete observation. There may be other
factors at work.
c.) Monitor the temperature increase of the battery while cranking
This is not practical and would be an incomplete observation.
d.) *Observe the voltage drop from battery to engine during cranking
Correct. As current draw increases, the battery should maintain its voltage level. If it drops
too much, more current will have to be used to obtain the same number of watts to crank the
engine. Engine cranking would slow while voltage drops.

S4-Q98.) 24 Volt lead-acid batteries require what float rate voltage?

a.) 20V
Incorrect response. This voltage is lower than the system it is supplying current to.
b.) *26V
Correct. There must be a voltage differential to obtain current flow, but only a slight voltage
differential is necessary.
c.) 24V
Incorrect response. There is no voltage differential between battery and system, no current could
flow.
d.) 42V
This differential is too high and could cause damage to the system.

S4-Q99.) Mechanical louvers should be actuated in what mode?

a.) Energize to open
This may prevent airflow during operation if there were a failure. This could lead to overheating.
b.) Temperature activated
Not practical. A failure could lead to overheating.
c.) *Energize to close
Correct. If normal position is open, the system would always have airflow even in times of
failure.
d.) Manual
Not practical. Someone would have to be there to open or close the louvers. Defeats
the purpose of automatic systems.

Page 83 - EGSA Apprentice Certification Program Study Guide