Why will too many electrical devices operating at one time after blow a fuse or trip a circuit breaker?

Why will too many electrical devices operating at one time after blow a fuse or trip a circuit breaker?
by

1 Answer

Answer :

The load exceeds the limit of the breaker or fuse. For example a20 amp breaker on a 120 volt circuit will handle 2400 watts. Exceedthat wattage and the breaker will trip or the fuse will blow.
by

Related questions

A fuse will 'blow' if _____________. A. an electric motor is stopped suddenly by opening a switch B. the flow of current to the protection device is reversed C. the electrical current exceeds the rated value of the fuse D. unequal resistors are connected in parallel

Description : A fuse will 'blow' if _____________. A. an electric motor is stopped suddenly by opening a switch B. the flow of current to the protection device is reversed C. the electrical current exceeds the rated value of the fuse D. unequal resistors are connected in parallel

Last Answer : Answer: C

To remove an alternator operating in parallel with another unit from the main electrical bus, you must FIRST _________. A. adjust the power factor on both units B. set the desired voltage on the outgoing alternator C. open the circuit breaker on the outgoing alternator D. remove the load from the outgoing alternator

Description : To remove an alternator operating in parallel with another unit from the main electrical bus, you must FIRST _________. A. adjust the power factor on both units B. set the desired voltage on ... C. open the circuit breaker on the outgoing alternator D. remove the load from the outgoing alternator

Last Answer : Answer: D

When a fluorescent lamp has reached the end of its useful life, it should be replaced immediately, or the resultant flashing may _____________. A. blow the lamp's circuit breaker B. explode, causing glass to fly in all directions C. short circuit the ballast transformer D. damage the starter and the ballast

Description : When a fluorescent lamp has reached the end of its useful life, it should be replaced immediately, or the resultant flashing may _____________. A. blow the lamp's circuit breaker B. explode, ... fly in all directions C. short circuit the ballast transformer D. damage the starter and the ballast

Last Answer : Answer: D

Which of the following conditions is most likely to occur if a single element fuse were used to replace a blown dual element fuse in a motor controller circuit? A. The fuse will blow when the motor is started. B. The fuse works, but overheats at high motor loads. C. The motor runs at reduced voltage. D. The motor runs normally.

Description : Which of the following conditions is most likely to occur if a single element fuse were used to replace a blown dual element fuse in a motor controller circuit? A. The fuse will blow when the motor ... overheats at high motor loads. C. The motor runs at reduced voltage. D. The motor runs normally.

Last Answer : Answer: A

What is the difference between a fuse and a circuit breaker ?

Description : What is the difference between a fuse and a circuit breaker ?

Last Answer : Fuse : It is a type of soft metal wire which, when more than the required current flows through the wire, burns it, disconnects the electrical circuit from the source and protects the valuable ... or fault in the power supply line . This breaks the static contact and protects it from accidents.

The schematic diagram shown in the illustration uses symbol 'A' to represent a/an _________. EL-0011 A. non-renewable fuse link B. circuit breaker coil C. overload relay coil D. thermal overload heater

Description : The schematic diagram shown in the illustration uses symbol 'A' to represent a/an _________. EL-0011 A. non-renewable fuse link B. circuit breaker coil C. overload relay coil D. thermal overload heater

Last Answer : Answer: D

In order to safely carry out repairs to a generator circuit breaker, it must be isolated from the bus. This is accomplished by opening the _____________. A. reverse power relay B. bus disconnect link C. generator bus fuse connections D. power directional relay

Description : In order to safely carry out repairs to a generator circuit breaker, it must be isolated from the bus. This is accomplished by opening the _____________. A. reverse power relay B. bus disconnect link C. generator bus fuse connections D. power directional relay

Last Answer : Answer: B

If an electric motor fails to start, you should FIRST check the _____________. A. phase sequence B. ampere load C. fuse or circuit breaker D. line frequency

Description : If an electric motor fails to start, you should FIRST check the _____________. A. phase sequence B. ampere load C. fuse or circuit breaker D. line frequency

Last Answer : Answer: C

When an AC or a DC motor fails to start, the FIRST step in troubleshooting should be to check the ____________. A. motor windings for obvious opens B. motor controller leads for continuity C. fuse or circuit breaker D. motor controller leads for grounds

Description : When an AC or a DC motor fails to start, the FIRST step in troubleshooting should be to check the ____________. A. motor windings for obvious opens B. motor controller leads for continuity C. fuse or circuit breaker D. motor controller leads for grounds

Last Answer : Answer: C

A circuit breaker differs from a fuse in that a circuit breaker _____________. A. melts and must be replaced B. is enclosed in a tube of insulating material with metal ferrules at each end C. gives no visual indication of having opened the circuit D. trips to break the circuit and may be reset

Description : A circuit breaker differs from a fuse in that a circuit breaker _____________. A. melts and must be replaced B. is enclosed in a tube of insulating material with metal ferrules at each end C. gives no visual indication of having opened the circuit D. trips to break the circuit and may be reset

Last Answer : Answer: D

A circuit breaker and a fuse have a basic similarity in that they both _____________. A. can be reset to energize the circuit B. should open the circuit when overloaded C. will burn out when an over current flow develops D. all of the above

Description : A circuit breaker and a fuse have a basic similarity in that they both _____________. A. can be reset to energize the circuit B. should open the circuit when overloaded C. will burn out when an over current flow develops D. all of the above

Last Answer : Answer: B

Differentiate between a fuse and a circuit breaker.

Description : Differentiate between a fuse and a circuit breaker.

Last Answer : Fuse is a low current interrupting device. It is a copper or an aluminium wire. Circuit breaker is a high current interrupting device and it act as a switch under normal operating conditions.

Which of the following is the least expensive protection for overcurrent is low voltage system ? (a) Rewireable fuse (b) Isolator (c) Oil circuit breaker (d) Air break circuit breaker (e) None of the above

Description : Which of the following is the least expensive protection for overcurrent is low voltage system ? (a) Rewireable fuse (b) Isolator (c) Oil circuit breaker (d) Air break circuit breaker (e) None of the above

Last Answer : (a) Rewireable fuse

How will a molded-case circuit breaker react after it has tripped, as a result of an overloaded circuit? A. The breaker will trip again if immediately reset. B. The breaker handle will lock in the OFF position. C. The breaker handle will lock in the tripped position until the thermal element cools down. D. The breaker handle cannot be moved to the OFF position until the thermal element cools down.

Description : How will a molded-case circuit breaker react after it has tripped, as a result of an overloaded circuit? A. The breaker will trip again if immediately reset. B. The breaker handle will lock in ... down. D. The breaker handle cannot be moved to the OFF position until the thermal element cools down.

Last Answer : Answer: A

My current microwave oven causes my circuit breaker to trip if I use it at the same time as my toaster oven. Will this microwave solve that problem?

Description : My current microwave oven causes my circuit breaker to trip if I use it at the same time as my toaster oven. Will this microwave solve that problem?

Last Answer : It's doubtful; I wouldn't be able to answer that for sure unless I knew the particulars of your set-up (what is your microwave/toaster's draw? what kind of breaker do you have? etc.), but I don't see any reason why this microwave would help that situation.

Fuses placed in series with a thermal trip-type circuit breaker are used for _____________. A. time-delay protection B. short-circuit protection C. short duration surge protection D. sustained overload protection

Description : Fuses placed in series with a thermal trip-type circuit breaker are used for _____________. A. time-delay protection B. short-circuit protection C. short duration surge protection D. sustained overload protection

Last Answer : Answer: B

With which of the following, a circuit breaker must be equipped for remote operation ? (a) Inverse time trip (b) Time-delay trip (c) Shunt trip (d) None of the above (e) All of the above

Description : With which of the following, a circuit breaker must be equipped for remote operation ? (a) Inverse time trip (b) Time-delay trip (c) Shunt trip (d) None of the above (e) All of the above

Last Answer : (c) Shunt trip

An instantaneous-trip-type fuse will _____________. A. open as soon as the load current exceeds its set point B. allow a preset delay between overcurrent and melting C. open a circuit by using a time delay element with a magnetic trip D. reset itself when the overcurrent is corrected

Description : An instantaneous-trip-type fuse will _____________. A. open as soon as the load current exceeds its set point B. allow a preset delay between overcurrent and melting C. open a circuit by using a time delay element with a magnetic trip D. reset itself when the overcurrent is corrected

Last Answer : Answer: A

A circuit breaker for a 300 KW alternator is rated at 470 amperes of full continuous load. The amount of overcurrent allowed is 125%. Which of the following conditions will trip the breaker? A. Sustained current flow of 470 amperes. B. Sustained current flow of 500 amperes for 10 minutes. C. Momentary starting load of 550 amperes. D. Sustained current flow of 590 amperes.

Description : A circuit breaker for a 300 KW alternator is rated at 470 amperes of full continuous load. The amount of overcurrent allowed is 125%. Which of the following conditions will trip the breaker? A. ... 10 minutes. C. Momentary starting load of 550 amperes. D. Sustained current flow of 590 amperes.

Last Answer : Answer: D

If a circuit breaker that utilizes built-in, current limiting fuses (CLF's) cannot be closed, the problem may be traced to __________. A. a blown CLF plunger holding the trip bar in the open position B. a missing CLF C. a misaligned limiter housing assembly D. all of the above

Description : If a circuit breaker that utilizes built-in, current limiting fuses (CLF's) cannot be closed, the problem may be traced to __________. A. a blown CLF plunger holding the trip bar in the open position B. a missing CLF C. a misaligned limiter housing assembly D. all of the above

Last Answer : Answer: D

Undervoltage trips are frequently installed on switchboard circuit breakers to trip ____________. A. out generators in the event of severe arcing or sparking B. out generators when there is reversal of power in the main circuit C. the breaker if the generator overspeeds by 5%, but continues to run D. out generators when there is low voltage in the main circuit

Description : Undervoltage trips are frequently installed on switchboard circuit breakers to trip ____________. A. out generators in the event of severe arcing or sparking B. out generators when there is reversal of power ... , but continues to run D. out generators when there is low voltage in the main circuit

Last Answer : Answer: D

You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0°. If you close the circuit breaker at this moment _____________. A. the incoming machine will accept all of the load B. the incoming machine will trip out on low voltage release C. a hazardous condition will be created by the cross current between the machines D. a hazardous condition will be created by the incoming machine being at a higher frequency than the bus

Description : You are attempting to parallel two AC generators and the synchroscope pointer stops at a position other than 0°. If you close the circuit breaker at this moment _____________. A. the incoming ... hazardous condition will be created by the incoming machine being at a higher frequency than the bus

Last Answer : Answer: C

The arc resulting from the tripping of a circuit breaker is prevented from damaging the contacts by _____________. A. designing the contacts to open slowly B. directing the arc into an arc chute C. an inverse timed thermal trip for short circuit currents D. instantaneous magnetic trip for overload currents

Description : The arc resulting from the tripping of a circuit breaker is prevented from damaging the contacts by _____________. A. designing the contacts to open slowly B. directing the arc into an ... an inverse timed thermal trip for short circuit currents D. instantaneous magnetic trip for overload currents

Last Answer : Answer: B

The purpose of a main switchboard circuit breaker's reverse-power trip is to _____________. A. prevent main circuit overload B. protect the circuit breaker blowout coil C. prevent alternator motorization D. prevent low voltage tripout

Description : The purpose of a main switchboard circuit breaker's reverse-power trip is to _____________. A. prevent main circuit overload B. protect the circuit breaker blowout coil C. prevent alternator motorization D. prevent low voltage tripout

Last Answer : Answer: C

Magnetic circuit breaker has ______ trip action. (a) delayed (b) instantaneous (c) both of the above (d) none of the above

Description : Magnetic circuit breaker has ______ trip action. (a) delayed (b) instantaneous (c) both of the above (d) none of the above

Last Answer : (b) instantaneous

Thermal circuit breaker has (a) delayed trip action (b) instantaneous trip action (c) both of the above (d) none of the above

Description : Thermal circuit breaker has (a) delayed trip action (b) instantaneous trip action (c) both of the above (d) none of the above

Last Answer : (a) delayed trip action

Where should you use a trip-free circuit breaker?

Description : Where should you use a trip-free circuit breaker?

Last Answer : In current sensitive or nonemergency systems.

What is a trip-free circuit breaker?

Description : What is a trip-free circuit breaker?

Last Answer : A circuit breaker that will trip even if the operating mechanism is held ON.

What are the three types of circuit breaker trip elements?

Description : What are the three types of circuit breaker trip elements?

Last Answer : Thermal, magnetic, and thermal-magnetic

Magnetic circuit breaker has ______ trip action.

Last Answer : Magnetic circuit breaker has instantaneous trip action.

The voltage appearing across the contacts after opening of the circuit breaker is called______voltage. (a) recovery (b) surge (c) operating (d) arc (e) none of the above

Description : The voltage appearing across the contacts after opening of the circuit breaker is called______voltage. (a) recovery (b) surge (c) operating (d) arc (e) none of the above

Last Answer : (a) recovery

In addition to short circuits and sustained overloads, fuses are likely to blow due to _____________. A. loose fuse clips B. low ambient temperatures C. low contact resistance D. all of the above

Description : In addition to short circuits and sustained overloads, fuses are likely to blow due to _____________. A. loose fuse clips B. low ambient temperatures C. low contact resistance D. all of the above

Last Answer : Answer: A

A fuse will blow for all the listed reasons EXCEPT ________. A. excessive vibration B. extremely hot surroundings C. loose fuse clips D. low contact resistance within the fuse

Description : A fuse will blow for all the listed reasons EXCEPT ________. A. excessive vibration B. extremely hot surroundings C. loose fuse clips D. low contact resistance within the fuse

Last Answer : Answer: D

Electrical jellies! Got a circuit breaker (home) that has popped and won't reset. Suggestions?

Description : Electrical jellies! Got a circuit breaker (home) that has popped and won't reset. Suggestions?

Last Answer : My husband, who was a master electrician, said you need to call a professional. You either have a bad breaker or the breaker that refuses to reset is saving your life because you have a dead short some place and your house would burn down if ithe breaker wasn’t tripped.

What are the common sizes of circuit breaker panel for all electrical home?

Description : What are the common sizes of circuit breaker panel for all electrical home?

Last Answer : 200 amp is the most common size used in most homes.

Before any work on electrical or electronic equipment is performed, which of the following precautions should be carried out? A. De-energize the applicable switchboard bus. B. Bypass the interlocks. C. Secure and tag the supply circuit breaker in the open position. D. Station a man at the circuit supply switch.

Description : Before any work on electrical or electronic equipment is performed, which of the following precautions should be carried out? A. De-energize the applicable switchboard bus. B. Bypass the interlocks. C. ... supply circuit breaker in the open position. D. Station a man at the circuit supply switch.

Last Answer : Answer: C

A ground in an electrical circuit outside the engine room _____________. A. cannot be detected under normal conditions B. is of no consequence to engineering personnel C. is indicated at the branch circuit breaker panel D. is indicated by the ground detecting lamps on the main switchboard

Description : A ground in an electrical circuit outside the engine room _____________. A. cannot be detected under normal conditions B. is of no consequence to engineering personnel C. is indicated at the branch circuit breaker panel D. is indicated by the ground detecting lamps on the main switchboard

Last Answer : Answer: D

Electrical circuits are protected against overheating by means of a/an ______________. A. circuit breaker B. amplifier C. diode D. capacitor

Description : Electrical circuits are protected against overheating by means of a/an ______________. A. circuit breaker B. amplifier C. diode D. capacitor

Last Answer : Answer: A

A ground can be defined as an electrical connection between the wiring of a motor and its ____________. A. shunt field B. circuit breaker C. metal framework D. interpole

Description : A ground can be defined as an electrical connection between the wiring of a motor and its ____________. A. shunt field B. circuit breaker C. metal framework D. interpole

Last Answer : Answer: C

A circuit breaker is designed to protect an electrical circuit from damage caused by :

Description : A circuit breaker is designed to protect an electrical circuit from damage caused by :  (A) Over load (B) Short circuit (C) Over current (D) All of the above

Last Answer : A circuit breaker is designed to protect an electrical circuit from damage caused by :  (A) Over load (B) Short circuit (C) Over current (D) All of the above

In an electrical circuit, a fuse is connected (a) in the live wire (b) in the neutral wire (c) in the earth wire (d) anywhere—it makes no difference

Description : In an electrical circuit, a fuse is connected (a) in the live wire (b) in the neutral wire (c) in the earth wire (d) anywhere—it makes no difference

Last Answer : Ans:(a)

The function of fuse in an electrical circuit is (a) avoid electric shocks (b) regulate the flow of current (c) break the circuit in case of overloading or short circuiting (d) switch off current

Description : The function of fuse in an electrical circuit is (a) avoid electric shocks (b) regulate the flow of current (c) break the circuit in case of overloading or short circuiting (d) switch off current

Last Answer : Ans:(c)

A device which is used to limit the current in an electrical circuit is called a - (1) Grid (2) Fuse (3) Hub (4) Conductor

Description : A device which is used to limit the current in an electrical circuit is called a - (1) Grid (2) Fuse (3) Hub (4) Conductor

Last Answer : (2) Fuse Explanation: A fuse places a limit on the amount of current that can be drawn by an electric circuit by opening (blowing or melting) when the current exceeds a preset limit. This protects the circuit and the surroundings from fire or damage in the case of an overload or short circuit.

A device which is used to limit the current in an electrical circuit is called a (1) Grid (2) Fuse (3) Hub (4) Conductor

Description : A device which is used to limit the current in an electrical circuit is called a (1) Grid (2) Fuse (3) Hub (4) Conductor 

Last Answer : Fuse

An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. cause the slip rings to melt C. cause a low voltage differential to develop between the armature and the bus D. cause high currents to be induced in the field windings

Description : An AC generator operating in parallel loses its excitation without tripping the circuit breaker. This will __________. A. not affect the faulty generator due to the compensation of the other generators B. ... between the armature and the bus D. cause high currents to be induced in the field windings

Last Answer : Answer: D

When the operating handle of a molded case circuit breaker is in the mid-position, it indicates the circuit breaker is _____________. A. in the 'opened' position B. in the 'closed' position C. tripped D. reset

Description : When the operating handle of a molded case circuit breaker is in the mid-position, it indicates the circuit breaker is _____________. A. in the 'opened' position B. in the 'closed' position C. tripped D. reset

Last Answer : Answer: C

When the operating handle of a molded-case circuit breaker is in the mid-position, the circuit breaker is indicated as being ____________. A. in the 'closed' position B. in the 'opened' position C. tripped D. reset

Description : When the operating handle of a molded-case circuit breaker is in the mid-position, the circuit breaker is indicated as being ____________. A. in the 'closed' position B. in the 'opened' position C. tripped D. reset

Last Answer : Answer: C

When the operating handle of a molded-case circuit breaker is in the mid-position, this indicates that the circuit breaker is _____________. A. on B. off C. reset D. tripped

Description : When the operating handle of a molded-case circuit breaker is in the mid-position, this indicates that the circuit breaker is _____________. A. on B. off C. reset D. tripped

Last Answer : Answer: D