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CFESA ELECTRICAL EXAM WITH COMPLETE
QUESTIONS AND CORRECT VERIFIED
ANSWERS(2025/2026) ALREADY GRADED A+
what happens to the current in a series circuit? - CORRECT ANSWER- It stays the
same everywhere in a parallel circuit the total resistance of the circuit will always be less than what
resistance? - CORRECT ANSWER- the smallest resistance
how do you find the total resistance of a series circuit? - CORRECT ANSWER- add
the resistances together
how do you find the total resistance of a parallel circuit? - CORRECT ANSWER-
1/RT = 1/R1 + 1/R2 + 1/R ...
If a circuit is wired parallel, and the supply voltage is 120 volts, each load must be
rated at what voltage? - CORRECT ANSWER- 120 volts
if a circuit has two elements wired in series, and each is rated at 120 volts, what voltage must be supplied to the circuit in order for the elements to heat at full
power? - CORRECT ANSWER- 240 volts
What is the advantage of using higher voltages? - CORRECT ANSWER- Lower
Current and wire size
Is there a negative and positive line in AC power supplies? - CORRECT ANSWER-
No
What do the following prefixes mean? Micro,Kilo,Mega,Milli - CORRECT
ANSWER- 1/1,000,000, 1000, 1,000,000, 1/
If you know the wattage and voltage, how do you determine the current? -
CORRECT ANSWER- Divide the wattage by the voltage
If you know the voltage and current how do you determine the wattage? -
CORRECT ANSWER- Multiply voltage times current
If a circuit is supplied with 100 volts and the total resistance of the circuit is 200
ohms, how much current will the circuit draw? - CORRECT ANSWER- .5 amps
If a piece of equipment is supplied 208 volts and the amp meter clamped to the
hot line reads 20 amps, what is the wattage of the load? - CORRECT ANSWER-
4160 Watts
What is the accepted maximum voltage difference between the name plate
voltage and the supplied voltage? - CORRECT ANSWER- + or - 10%
What is the voltage between any two hot lines of a 230 volt delta power supply? -
CORRECT ANSWER- 230V
what is the voltage between a hot line and ground on a 240 volt delta power
supply - CORRECT ANSWER- No usable voltage
what is the voltage between any two hot lines of a 230 volt grounded delta power
supply - CORRECT ANSWER- 230V
draw a diagram of a 230 volt grounded delta power supply. label all of the
voltages and the wild leg - CORRECT ANSWER-
what is the wild leg? - CORRECT ANSWER- leg with higher than 120v to ground
or neutral
what danger is the wild leg? - CORRECT ANSWER- high voltage that will damage
120v component in the circuit what is the voltage between either of the non wild leg hot lines and neutral in a
230 volt grounded delta system? - CORRECT ANSWER- 115v
how do you determine which hot line is the wild leg in a 250 volt grounded delta
power supply? - CORRECT ANSWER- the one that does not measure 120 volts to
neutral or ground what danger is there when replacing a three phase circuit breaker in a 230 volt
grounded delta power supply? - CORRECT ANSWER- crossing the hot lines and
supplying the wild leg to the wrong terminal in the unit.
Why is a "WYE" power supply so versatile - CORRECT ANSWER- can get 120v and
208v as well as single and three phase
What is the voltage between any two hot lines in a 208 volt WYE power supply? -
CORRECT ANSWER- 208v
What is the voltage between any hot line and neutral or ground in a 208 volt WYE
power supply? - CORRECT ANSWER- 120v
What is the voltage from any hot line to ground or neutral, on a 480 volt WYE
power supply? - CORRECT ANSWER- 277v
if you had a commercial building and you had a three phase supply to your building how many different incoming power supplies would you need if the
incoming three phase supply was three phase delta? - CORRECT ANSWER- 2
can high voltage result in and overheating problem when trying to control the
temp of an oven? - CORRECT ANSWER- yes
how many resistances must you have to have a balanced load? - CORRECT
ANSWER- 3 or a multiple of 3
what is the formula for calculating the current draw from the wattage and voltage
on a three phase balanced load? - CORRECT ANSWER- amperage = wattage /
(voltage X 1.732)
how can you tell if a piece of equipment will be a balanced load or not? -
CORRECT ANSWER- must have 3 or a multiple of three loads
Joe says a convection oven that has three heating elements, and a single phase
blower motor is a balanced three phase load. Jim says it is not. Who is right? -
CORRECT ANSWER- Jim, sing phase motor unbalances the load
Electricity will always follow what path? - CORRECT ANSWER- Path of least
resistance
Why should all equipment be grounded? - CORRECT ANSWER- safety and code
How should the earth ground from the main fuse or breaker panel be connected?
- CORRECT ANSWER- from grounding bus bar to ground rod or metal water pipe
in order for a receptacle to be properly grounded, the ground wire must run to
where? - CORRECT ANSWER- all the way back to the panel
How much resistance should you read from a neutral connection to a ground
connection? - CORRECT ANSWER- 0 ohms
What is the difference between neutral and ground? - CORRECT ANSWER- the
neatural normall carries current, the ground does not Can you get shocked from the casing on a piece of equipment if it is properly
grounded? - CORRECT ANSWER- No
Ground wires must always be what colors? - CORRECT ANSWER- green, green
with yellow tracer, or bare white
How much current does a short circuit draw? - CORRECT ANSWER- Infinite Amps
if a cord on a unit is shorted, can it damage the power switch on the piece of
equipment? - CORRECT ANSWER- No
if a heating element on an electric grill is shorted could it damage the thermostat?
- CORRECT ANSWER- Yes
What is MGS wire made of? - CORRECT ANSWER- Nickel tinned copper, mica
insulated with fiberglass braid
which wire should be used on a pizza oven operating at 650 degrees? - CORRECT
ANSWER- MGS
What is special about SO or SJO cord that makes it desirable in the commercial
food service industry? - CORRECT ANSWER- Grease and oil resistant
Ground wires must always be what color(s)? - CORRECT ANSWER- Green, green
with yellow tracer, or bare metal
Neutral wire(s) must always be what color? - CORRECT ANSWER- White
what size THHN wire should be used for a 20 amp load? - CORRECT ANSWER- 12
gauge
What size TGGT wire should be used for a 30 amp load? - CORRECT ANSWER- 12
gauge
What size SO cord should be used for a 40 amp load? - CORRECT ANSWER- 8
gauge
Give three common reasons for wire failures - CORRECT ANSWER- undersized,
temp rating too low, poor connections
Why must burned or discolored wire be replaced? - CORRECT ANSWER- once
burned or discolored the current carrying capacity drops significantly. Also connections will overheat.
If you put new terminals on discolored wire what will happen? - CORRECT
ANSWER- they will burn off again
Many high temp wire insulations will turn dark, or brown after a short period of
use in high ambient temps. What does this color change indicate? - CORRECT
ANSWER- That the wax coating on the wire has become hot from ambient
conditions. this wire is usually still clean and fully functional.
Standard electric terminal clips are made of what materials? - CORRECT
ANSWER- Copper or brass
What happens to standard terminals when used in high temp applications? -
CORRECT ANSWER- they oxidize, weaken, and burn off
High temp terminals are made of what materials? - CORRECT ANSWER- nickel,
nickel tinned steel, or plain steel
The sharp side of the jaws on a non insulated terminal crimping tool should
always be on what side of the barrel when crimping on a terminal? - CORRECT
ANSWER- the unsemed side
Can standard plastic wire nuts be used in ovens, ranges, etc? - CORRECT
ANSWER- No
In high temp applications, the best wire nuts are made of what material? -
CORRECT ANSWER- Porcelain
Before installing a wire nut, should you twist the wires together or lay them side
by side? - CORRECT ANSWER- Side by side
What do bare wires hanging out of the bottom of the wire nut indicate? -
CORRECT ANSWER- wires were stripped too far back, or the wire nut is too small
How does a split bolt connector work? - CORRECT ANSWER- wires laid inside the
split section and the nut is tightened
Split bolt connectors are normally used when? - CORRECT ANSWER- when wire
nuts are not large enough
After a split bolt connection has been made what else must be done before the
power can be turned on? - CORRECT ANSWER- insulated with tape to prevent
the connection from shorting
How do you know if a switch is motor rated? - CORRECT ANSWER- Has FLA or HP
marked on the swithc
Why are motor rated switches needed? - CORRECT ANSWER- To handle the
higher motor starting amperage
Describe a pilot duty rated switch - CORRECT ANSWER- Switch rated at 1 amp or
less, or rated in VA
Describe a power duty rated switch - CORRECT ANSWER- Switch with heavier
contacts that can handle more than a couple amps
Why cant you use power duty switches all the time even with pilot duty loads? -
CORRECT ANSWER- Power duty contact do not make tight enough if dusty or
oxidized. there is no arc on pilot loads to burn the contacts clean What causes intermittent operation or erratic operation of swithces that are used
on pilot duty loads? - CORRECT ANSWER- oxidation or dirt in the contacts
to be able to turn a light on or off at two separate locations, what kind and how
many switches are needed? - CORRECT ANSWER- 2 three way switches
describe a canopy switch - CORRECT ANSWER- small switch, with a threaded
shaft that mounts through a single hole
to remove a snap in rocker switch it is usually necessary to do what? - CORRECT
ANSWER- squeeze the tabs on the top and bottom
What are the advantages of using lighted rocker switches? - CORRECT ANSWER-
can tell when they are on and saves the cost of a separate indicator light Lighted rocker switches must have how many separate electric lines wired to
them? - CORRECT ANSWER- 2
Why are micro switches so widely used in equipment today? - CORRECT
ANSWER- multi-functional, low cost reliable, come in so many ratings and designs
what different ratings are microswitches available in? - CORRECT ANSWER- pilot,
power, and motor duty
What must you do if the microswitch is going to operate a motor load? -
CORRECT ANSWER- BE sure it is HP rated
What is the proper name for a knife switch with fuses, mounted in a metal
enclosure? - CORRECT ANSWER- Fused disonnect
what ratings are limit switches available in? - CORRECT ANSWER- pilot, power,
and motor rated
what is the main advantage of limit switches? - CORRECT ANSWER- sealed to
prevent dirt, water, oil, etc
the push button or selector portion of a motor switch is referred to as what? -
CORRECT ANSWER- operator
the switching part of a motor switch is referred to as what? - CORRECT
ANSWER- contact block
Can parts of motor switches made by different manufacturers be mixed? why or
why not? - CORRECT ANSWER- no, they will not fit together
to purchase a motor switch what all will you need to specify? - CORRECT
ANSWER- type of operator, contact block ratin needed, and number of N.O. and
or N.C. blocks
Are terminals P and L1 the same connections electrically? - CORRECT ANSWER-
Yes
What will happen if the power line is connected to terminal P - CORRECT
ANSWER- The pilot duty switch contact will melt down
In what voltages are infinite switches available - CORRECT ANSWER- 120,208,
and 240 volt What does the letter "B" in the model number stamped on the side of an infinite
switch signify? - CORRECT ANSWER- Broiler range switch
How does the "B" switch operate differently than a regular infinite switch? -
CORRECT ANSWER- More adjustment at the higher heat range of the curve
When sing an infinite switch, why don't you just connect a pilot light across the
load like you would any other time? - CORRECT ANSWER- the light will
constantly blink and the customer will think there is a problem
What is the max amp rating of an infinite switch? - CORRECT ANSWER- 15 amps.
in a heated area they handle no more than about 12 or 13 amps.
Do infinite switches hold up well when used and the max load rating? - CORRECT
ANSWER- no, the heat derates them
When replacing an infinite switch what else must you do? - CORRECT ANSWER-
replaces the wires and terminals to the switch
What are the two primary causes for failures of infinite switches? - CORRECT
ANSWER- burned wire connections and excessive ambient heat
What are the three critical things that must be matched if you substitute an
infinite switch? - CORRECT ANSWER- voltage, regular or broiler range, and
mounting type
What effect does high ambient temps have on a switch? - CORRECT ANSWER-
derates it, cannot handle the marked amperage If you are servicing a piece of equipment that uses multiple infinite switches, what
will happen if the old switch is "B" rated and the new one is not? - CORRECT
ANSWER- the unit will not heat as hot as it did with the old switch when the knob
is set to the same position
What will happen if the old switch was not "B" rated and the new one is? -
CORRECT ANSWER- the unit will get hotter than it did with the old switch when
the knob is set to the same position
The voltage rating of a fuse must always be greater than or equal to what? -
CORRECT ANSWER- The supplied voltage
