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How do you size the circuit breaker feeding a soft starter for a 195A full load current induction motor?
Wiki User
∙ 16y ago
Sizing circuit breakers for motors falls into a different category. Because of the inrush of current when the motor is in the stopped position, the breaker has to be sized to allow for this. Breakers usually are 250% of the nameplate full load amp rating. The wires that feed the motor are sized to 125% of the full load amps of the motor.
Wiki User
∙ 14y ago
Wiki User
∙ 16y agoUse a Ammeter and measure the current passing by and double what you measured. For example you measured 195A multiply by 2, that's 390A.
Wiki User
∙ 8y agoIt will say on the motors label how many amps the motor is. Then go next higher. If it reads 17.2 amps then you size it for 20 amps,
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How do you calculate breaker capacity of 10 hp three phase induction motor?
The first thing you have to do is find the full load amps of the motor. The wire size feeding the motor has to be 125% of the full load current. The breaker is usually 250% of the full load current. If the voltage and amperage had been added to the question the exact breaker size could have been calculated.
What is a circuit breaker?
A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. Circuit breakers are made in varying sizes, from small devices that protect an individual household appliance up to large switchgear designed to protect high voltage circuits feeding an entire city.Types:MCB (Miniature Circuit Breaker)-rated current not more than 100 A. Trip characteristics normally not adjustable. Thermal or thermal-magnetic operation. Breakers illustrated above are in this category.MCCB (Molded Case Circuit Breaker)-rated current up to 2500 A. Thermal or thermal-magnetic operation. Trip current may be adjustable in larger ratings.Fuses - These come in various sizes and make ups. The downside is most fuses need replacing after tripping.
How can you connect current transformer to ammeter in three phase?
You use three CTs, one per line conductor, each feeding a separate ammeter,
What is shunt coil?
A shunt-trip coil is a built-in component of a shunt-trip circuit breaker. It is a magnetic coil that can be energized externally to make the breaker trip to shut off the flow of current. For instance, fire sprinklers are sometimes required in the top of elevator shafts in case of a fire in the shaft. If the sprinklers were to spray water on the electric controls in the elevator cab, people could be hurt or killed, either from electrocution or from the elevator malfunctioning. In these cases, a shunt-trip breaker is installed in the circuit feeding the elevator controls, and the fire alarm system sends a trip signal if it detects waterflow from the sprinkler system. This trips the breaker and removes power from the elevator cab. Once tripped, a shunt-trip breaker requires a person to reset it manually.
What is the main function of an electric circuit?
The purpose of an electrical panel board or electrical distribution panel is to supply individual circuits from the main distribution board. As the board is supplied with one circuit of high capacity , it needs to be broken down into smaller branch circuits. Breakers accomplish this obligation by plugging into the panels main bus-bars. The load side of the breaker then goes to the specific load. The size of the breaker is dependant upon the size of the load of that circuit. The conductor that feeds the load is dependant upon the size of the breaker feeding that load.
How a circuit breaker prevent from too much current flowing into device?
The current (in question) flows through both the circuit AND the circuit breaker [they are in series]. Within the circuit breaker when the current exceeds the preset limit it will open the circuit thus stopping all current flow. There are two common ways of doing this 1) magnetism - a coil pulls a switch open 2) thermal - a bimetallic strip bends away from its contacts, which opens the circuit.
What size amp circuit breaker should be used for a pool light?
The pool light is usually on a 15 amp circuit. The breaker feeding this circuit must have a GFCI rating.
How do you calculate breaker capacity of 10 hp three phase induction motor?
The first thing you have to do is find the full load amps of the motor. The wire size feeding the motor has to be 125% of the full load current. The breaker is usually 250% of the full load current. If the voltage and amperage had been added to the question the exact breaker size could have been calculated.
Can you take a 14 awg wire and hook it to a 12 awg wire?
Yes as long as the breaker feeding the circuit is protected with a 15 amp breaker. The code states that the over current device can be no smaller than that of the smallest current carrying conductor. That will be the #14 wire with a capacity of 15 amps.
How a fuse controls the flow of electric current in a circuit?
A fuse does not control the flow in a circuit, it limits the current in a circuit. If the load in a circuit shorts out the fuse link melts and opens the circuit and stops the current flow and prevents the wires feeding the circuit from melting and catching fire. resist
Why would be no power in bedroom?
Blown fuse or circuit breaker. Wires loose on another outlet in that run feeding that bedroom's outlets.
What is a Circuit Breaker Panel?
A circuit breaker is a overcurrent device. It prevents fire.An electrical circuit is only as strong as its weakest link. When the voltage rating of a device is exceeded, it arcs. Current overloads are less obvious and easier to create. When the current rating of a device is overloaded, the device gets hot, eventually burning up. This can cause a fire.You want your breaker to be your weakest link, because it is designed to safely handle overcurrent situations. If your breaker is not the weakest link, wiring or a wiring device in your home will fail first, possibly setting your home on fire.Some things to remember:A breaker is a safety device. It is there to protect conductors and equipment.Only a Ground Fault Circuit Interrupter (GFCI) breaker will protect people from a shock or electrocution.If it pops, something is wrong. Chances are it is not the breaker! It is against the NEC to reset a breaker unless you know it was an overload condition. If it is a short-circuit, it must be fixed before resetting.Do not replace a breaker with a larger one. The circuit it is feeding cannot handle the extra current and will burn up before the new breaker trips.If a breaker trips frequently, chances are it is overloaded. Look into splitting the circuit it powers into multiple circuits on multiple breakers.If in doubt, call an electrician. Negligence is fatal with electricity.
How do you read breaker box amps?
The main breaker will have marking indicating size of electrical service, or if it is a fuse system....the fuses will have current ratings. If it is a subpanel, it might not have a main breaker. In this case you would have to look in the panel that the feed is coming from and find the size of the breaker that is feeding it. In either case you must look for the manufacturer's label that will have the maximum current the panel can handle, make sure the breaker feeding the panel doesn't exceed this rating.
What is a circuit breaker?
A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. Circuit breakers are made in varying sizes, from small devices that protect an individual household appliance up to large switchgear designed to protect high voltage circuits feeding an entire city.Types:MCB (Miniature Circuit Breaker)-rated current not more than 100 A. Trip characteristics normally not adjustable. Thermal or thermal-magnetic operation. Breakers illustrated above are in this category.MCCB (Molded Case Circuit Breaker)-rated current up to 2500 A. Thermal or thermal-magnetic operation. Trip current may be adjustable in larger ratings.Fuses - These come in various sizes and make ups. The downside is most fuses need replacing after tripping.
How do you fix an electrical dead short in a house?
To avoid any short circuit in a house we suppose to have electrical panel with proper size of circuit breakers. These breakers installed to feed a number of circuits in the house which is controlled by the Electrical Code. The breaker ampacity is depend on the load size (light circuits, outlets, microwave, dryer, furnace, cenral vacuum). The individual circuits are calculated depend on the size of the load (like motors, transformers sucking a lot more power, current when they start) and this will be the base to figure out the proper wire size for feeding the circuit. When a short circuit occurs at the farthers point from the breaker this overcurrent device suppose to open up the circuit to avoid overheating ang fire.
What is the difference between a ground fault breaker and a gfci outlet?
A ground fault breaker is installed in the distribution panel and every device that is connected to the breaker in that circuit is protected. A GFCI receptacle is installed in a outlet receptacle box. They can be wired two ways. Direct wired will protect just the outlet of the box that it is mounted in or (in - out) wired where the GFCI receptacle protects all of the down stream ordinary receptacles in the circuit.They're the same thing."GFCI" is an acronym for "Ground Fault Circuit Interrupter". It "interrupts, or "breaks" the circuit if there is a ground fault.A ground fault is defined as any condition in which current goes somewhere other than the return wire. The GFCI constantly compares the current through the "hot" wire to the current returning through the neutral wire, and if there is any significant difference in the two, the GFCI interrupts the current, potentially saving lives.
What type of circuit has double 20amp breaker going to a separate box at that separate box there is a well pump with another 20amp breaker to that?
Sounds like a 240 volt sub panel feeding a well pump.
