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Fuse sizing is calculated by the size of the conductor. The conductor is calculated by the amperage to the load.
The above answer is partially right, however in calculating fuse sizes for say a motor load of 10 hp on 208 volts 3 phase. The table in 430.250 list this motor as pulling 30.8 amps. Conductor size would be 30.8 times 1.25 or 38.5 amps. This value would lead you to wire table 310.15(B)(16) and a conductor size of number 8THWN. This conductor is listed for 50 ampacity, however due to the starting current of the motor. A fuse could be sized at 30.8 times 1.75 or 53.9 amps. The next standard size would be 60 amps. the fuse size is above what the conductor is rated for, but because of motor overload protection the conductor is protected. If breakers were used instead of fuses, a breaker would be sized at 30.8 times 2.5 or 77 amps or 80 amp next standard size.
Wiki User
∙ 12y ago
Wiki User
∙ 12y agoIt needs to match the rating of the service and the panel itself. The panel will have an amperage rating and you should not exceed this.
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What is MSB in electrical wiring?
main switch board
Which type of Electrical wiring is used in your homes and offices?
Parallel for main circuits and series parallel for lighting circuits.
What are the required for electrical panel?
The main items required for an electrical panel include the panel box itself, fuses, and wiring. The wires are fed into the box and attached to a series of circuit breakers to allow electricity to be directed as needed.
How do you avoid overheating of the electrical wiring of the equipment?
Overheating of electrical wiring is overcome by installing the correct size conductors to carry the load amperage of the equipment. Use a larger size wire to the load. The main purpose of the breaker is to protect the wire that is connected to it. If the wire becomes overloaded due to a high current flow the breaker will trip.
What are mains sockets?
"Main sockets" is referring to fuse sockets, particularly the main fuse sockets for a fuse panel.
What is MSB in electrical wiring?
main switch board
What are practical uses of copper?
The main use is in electrical wiring.
What does the 75A battery fuse on a 96 Nissan altima control?
That is the main fuse. It protect all the wiring in the vehicle.
Is there a main fuse in a Hyundai Elantra?
Yes, a main fuse is located in the Hyundai Elantra engine bay fuse box. The main fuse is used for the alternator just in case the alternator experiences a power surge. It protect the rest of the electrical components.
Why does the main fuse on your Mazda bongo keep blowing?
More than likely a short in the wiring.
Can a fuse stop a 1991 Honda Accord from starting?
Yes, a blown main fuse will cut all electrical power to the vehicle.
How does a automotive fuse box work?
It's a central location for all electronics essentially. The main design of a fuse box is to hold fuses in a central location and a good testing/ diagnosing point for electrical problems. So you won't be chasing fuses and wiring all around the vehicle everytime you diagnose it.
Which IS a common sense safety procedure that can help prevent electrical accidents?
The main safety rule is to switch off at the mains before working on electrical equipment and wiring.
What are the main requirements for the house wiring?
SAFETY. Don't let any one that is not qualified to touch your home electrical system!
2002 KIA sportage and the main headlight fuse keeps blowing what could be wrong?
If the main headlight fuse keeps blowing out on a 2002 Kia Sportage, check for a short in the wiring. Also check to make sure there is no moisture in the headlight holder.
Which type of Electrical wiring is used in your homes and offices?
Parallel for main circuits and series parallel for lighting circuits.
Is there a fuse for the main electrical system when you turn the key on for a 97 sierra 1500?
I'm not quite sure what you mean by "Main electrical system"? Thier is a fuse linking to certain features and to other fuses specificaly for when the key is turned. You'll find this fuse in the main panel under the hood, and a separate but equal fuse in the panel in the cab of the pickup, It will be labled as IGN for ignition. As far as the "Main electrical system", No, for the battery, the computer, and most other "MAIN" items, these items do not care if the key is turnned or not. If this doesn't answer your question. Please re ask your question being more specific about what you mean by "Main Electrical System" and even go further by telling me what your actually having trouble with that would lead you to believe that you needed to know about a fuse and tell me what your ending goal is. What's broke. I can fix that easier than fixing a problem that you don't know why it needs fixing. Happy Hunting.
