Questions tagged [ampacity]
A portmanteau combining the words for Amperage and Capacity. Defined as the maximum current (Amperage) that a device or conductor can carry without sustaining immediate or progressive deterioration. Defined in some electrical codes.
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questions
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2answers
91 views
Why would this power mosfet be made in a surface mount package?
I’m looking at the CSD17303Q5 power mosfet which boasts a 100A max drain current. It confuses me why they have it in a VSON surface mount package because most pcbs would not be able to handle that ...
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5answers
151 views
Derating ampacity of a wire if it is stranded?
Do I need to derate a wire if it is stranded? Or will a #12 wire have the same ampacity whether or not it is stranded? Is this affected at all by AC versus DC?
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1answer
49 views
Battery connector and wire ampacity
I’m considering using a JST ACH connector with my LiPo, but I don’t understand whether the current rating on the data sheet is for aggregate or for each wire individually (which is my guess since they ...
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4answers
798 views
Ampacity of Conductive Tape
How do I measure ampacity of conductive tape? I want to replace a wired battery to equipment connection with copper adhesive tape because I need a very low profile on the connection.
The maximum ...
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1answer
83 views
Are rated cable ampacities per conductor or per circuit?
I'd like to construct a cable using connectors DigiKey 708-1190-ND to connect a 20A LED to its power supply. The connector is rated "32A". In this example the connector's third pin will not be ...
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1answer
102 views
120 Watts and 7.2 Volts, how many Amps?
For a project I need to switch on a simple handheld vacuum cleaner with an Arduino. I am thinking of using a relay or mosfet.
I opened the case and a 7.4 V 2200 mAh Li-Ion battery powers the motor, ...
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votes
2answers
88 views
Ampacity Testing
Just a simple understanding question.
If I obtained a DC bench power supply that has a current limit, could I test the ampacity of a wire by connecting said wire across the terminals?
So when I slowly ...
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1answer
183 views
Proper supply wiring for CNC router 4.1 kW 3Φ motor and 120 V accessories?
I'm building a CNC router table that has a three-phase 220 V spindle motor, and 120 V computer (and accessories). The spindle's nameplate:
As you can see it tops out at 20.3 A @ 220 V.
The VFD’s (...
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2answers
604 views
Determining safe current and fuse rating for LV LED lighting
My home builder pre-pulled a length of 18-8 solid copper wire (18 AWG, 8 insulated conductors inside single jacket) into the ceiling of a room where I want to use some LED lighting with a remote power ...
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votes
1answer
79 views
Suitable connector/wire for 3A output from PSU
I've searched through the questions that have been asked but none have dealt with this particular problem:
I'm designing a PSU board that will have, among other things, a 12V/3A regulator. I want to ...
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1answer
46 views
PSU for Ampacity test of connection
i have this problem. I have to validate with a test that my connection on my power board can carry the nominal current required by the specs.
For current around 10A the setup I'm using is a ...
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vote
3answers
15k views
How to choose proper size of high power DC cable connections
I can't understand how to properly calculate AWG of a cable working in DC at high current: I found several tables for AC, but I don't know if/how they can be applied to DC.
My system is rated 70V/...
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2answers
1k views
Magnet Wire Insulation
A close examination on magnet wire tables of various manufacturers like `http://www.epicos.com/EPCompanyProfileWeb/Content/CABLES/Magnet%20Wire%20Data%20Sheet.pdf (page 9),shows that the ratio of the ...
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5answers
8k views
Which wire gauge for a 250 amp source?
I have no real experience with this stuff...
I have two 6V 220Ah DC golf cart batteries that I want to put in series to make a 12V 220Ah output that I will connect to a 3000W power inverter, my ...
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vote
1answer
1k views
Calculate gauge of wire with voltage and current
I would like to figure out these two things:
X gauge of wire needed dependent on the current needed, and the length.
X max length of wire dependent on the current, and the gauge.
3
votes
1answer
1k views
Current capacity of copper wires in vacuum
I’d like to know the current carrying capacity of copper wires in vacuum.
The current plan (NPI) calls for sending ~3 amps through the vacuum space of a cryostat.
Has anyone done this? Have any ...
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votes
3answers
15k views
Voltage Drop and Safe Current Load on CAT5 Cable
I am going to use this passive PoE injector cable set to power a Raspberry Pi model B.
The Raspberry Pi model B consumes between 700mA-1000mA (mine will also be powering the RPi Camera Module). Using ...
3
votes
1answer
2k views
3 phase circuit, 3 x single-phase (hot-hot) loads: what ampacity?
I'm not an electrician (thus the question), but I'd like to know what is possible from a specification standpoint.
Let's say we have a standard 3 phase power supply for a commercial building. We want ...
6
votes
2answers
629 views
Allowable ampacity through cable
For an application we are considering pulsing a current through a conductor.
The conductor have an ampacity rating of 12.5A for continuous operation.
During the pulse we get currents around 25A and ...
5
votes
1answer
3k views
Are there any rules of thumb when computing pulse current ratings for PCB traces?
Say I have a surface PCB trace, 4 oz, 50 mils. That trace should be able to carry around 15 amps continuous, according a calculator I'm using. (Obviously your trace ampacity estimates may vary with ...
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1answer
1k views
how to calculate thickness of copper conductor
Can you please explain how to calculate thickness of a copper conductor for the next task:
I would like to use a DC power supply instead of some batteries for my sensors. So we have V volts and AH ...
