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Old 12-29-2018, 01:59 PM
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Default Electric component ratings AC vs. DC

Electric go karts (electric vehicles in general) need many different "companion" components like switches (on/off, brake lever, 3-way etc.), fuses/circuit breakers, conductors (wires), connectors & also connectors/ports.

They should/really need to be "properly rated" for the particular purpose.

How do you know?
How do you figure the proper rating?

To do it yourself, first you have to establish the parameters of the particular circuit your working on.

You can do this by figuring the (maximum) voltage the circuit will ever encounter
(24VDC = ~26.6VDC, 36VDC = 39.9VDC, 48VDC = 53.2VDC, 60VDC = ~66.5VDC etc.)
(plus usually ~10% for an added safety margin, like 60VDC = ~72VDC)
...the maximum amperage/current that will be flowing thru it
...& also the purpose (very important), what the circuits function is (or being used for) like for a power carrying circuit, signal/control circuit, simply connecting or whatever.

Once you have established these parameters you can properly match components that meet those requirements.


What's that got to do with AC vs. DC?

In the DIY world we repurpose a lot of stuff, for a variety of reasons. (cost, availability etc.)

Looking around (for years) there is literally tons of stuff made for use with AC circuits & rated as such.
(mostly 110VAC here in the USA & ~220VAC in Europe & most Asian countries)
...but, most everything with DC ratings is for automotive/marine use. (12VDC)

So, what do you use with 36VDC, 48VDC, 60VDC etc. systems?

Lets look into it, here is some good info to begin the conversation

https://www.mouser.com/blog/which-sw...f-its-ac-or-dc
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Old 12-30-2018, 08:03 AM
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Default Types of Loads & DC Rule of Thumb

I found some really good info & wanted to share

Types of Loads
An electric load is the amount of electric power delivered or required at any specific point or points on a system. The requirement originates at the energy consuming equipment of the consumers. More simply put, a load is the piece of equipment you turn on and off.

Resistive loads primarily offer resistance to the flow of current. Examples of resistive loads include electric heaters, ranges, ovens, toasters, and irons. If the device is supposed to get hot and doesn't move, it's most likely a resistive load.

Inductive loads are usually devices that move and normally include electric magnets, like an electric motor. Examples of inductive loads include such things as power drills, electric mixers, fans, sewing machines, and vacuum cleaners. Transformers also produce inductive loads.

High Inrush loads draw a higher amount of current or amperage when first turned on, compared to the amount of current required to continue running. An example of a high inrush load is a light bulb, which may draw 20 or more times its normal operating current when first turned on. This is often referred to as lamp load. Other examples of loads that have high inrush are switching power supplies (capacitive load) and motors (inductive load).
https://www.carlingtech.com/amp-hp-volts

DC Rule of Thumb
For those switches that list an AC voltage rating only, the "DC Rule of Thumb" can be applied for determining the switch's maximum DC current rating. This "rule" states the highest amperage on the switch should perform satisfactorily up to 30 volts DC. For example, a switch which is rated at 10A 250VAC; 15A 125VAC; 3/4HP 125-250VAC, will be likely to perform satisfactorily at 15 amps up to 30 volts DC (VDC).
https://www.carlingtech.com/amp-hp-volts#3

...a lot more interesting info
https://www.carlingtech.com/switch-learn-more
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Old 12-30-2018, 11:07 AM
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Default Whats it all mean

In an effort to confirm this info, I rounded up the battery box off an old Razor scooter & looked at what components the factory used.

It's a Razor E100 24VDC battery box with an on/off switch & a round 3-pin charge port mounted/glued to it.
The switch is labeled:
KCD1
16A 125VAC
16(4)A 250VAC T85

Which means,
@ 125VAC, 16 = resistive load amperage; A= amperage;

@250VAC, 16 = resistive load amperage; (4) = inductive load amperage; A= amperage; T85= Maximum operating temperature in centigrade

* the charge port looks to be a standard round 3-pin (female connector with male pins) & doesn't have any label or markings.

So, if the Razor factory used a switch with these ratings, it seems to confirm the afore mentioned "DC Rule of Thumb"


Ok, that gives us info on using AC rated components on DC systems, but only on systems up to 30VDC.
& that would really be mostly for (up to) 24VDC systems like Power Wheels & kids toys.
(13.3VDC x 2 = 26.6VDC + 2.6VDC (10% safety margin)= 28.9VDC)

What about our bigger "toys"?
...like 36VDC, 48VDC or 60VDC systems?

Well, lets look into that.
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Old 01-01-2019, 10:04 AM
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Default

Quote:
Originally Posted by Functional Artist View Post

What about our bigger "toys"?
...like 36VDC, 48VDC or 60VDC systems?
This is (I quickly found) where things get "controversial"
While doin' research, over the last couple of months & asking questions on various forums about "the proper components for a 60VDC system", I received "vague" answers like, "you gotta use the properly rated stuff" & "you can't just guess that a switch rated for AC use will work on a DC circuit".

OK, but why?
Wanting to know more, I started digging deeper & asked:

"So far, I have found a few 72VDC rated switches like this:
An on-off switch (72VDC 16A) for the (power lock) ~$10.00
https://www.mouser.com/ProductDetail/633-JWL21RA1A
or
an on-off-on switch (250VDC 15A) for the (3-speed function) ~$13.00 https://www.mouser.com/ProductDetail/611-PT103SSQ
...& still looking for a compatible off-(momentarily) on switch for the (reverse function)
But, they seem way "over built" to control simple "signal" circuits.
Yes, these circuits are "pack voltage" (60VDC) but, they should not carry much (if any) "actual" current.
This speed controller should only draw maybe ~250mA
...& I don't think there should not be much of an amp draw from the reverse & 3-speed circuits at all.
Only the "big power" wires will ever carry the high amperage. (up to 35A)
The thick red (+) & thick black (-) "Power" / "Battery" wires, "carry the current" from the battery pack to the speed controller
...& the thick blue, thick yellow & thick green "Motor" / "Power" wires, "carry the current" from the speed controller to the motor.

So, "thinkin' it thru" & "outside of the box" even, I was thinking, what is the "worst case scenario" if any one of these switches ever failed?
1.) On/off switch:
If it failed in the "open" position, the speed controller would not turn on.
If it failed in the "closed" position, the speed controller would not turn off.
2.) Reverse switch:
If it failed in the "open" position, the speed controller would not activate the reverse function.
If it failed in the "closed" position, the speed controller would be stuck in reverse mode.
3.) 3-Speed switch:
If it failed in the "open" position, the speed controller would operate (in default mode) at med speed.
If it failed in the "closed" position, the speed controller would be stuck in either low or high speed.
I don't see where, if any of these switches failed, it would or could cause an unsafe or "runaway" situation.
But, I figured I'd run it by you guys to get some input from electronic experts.
Thanks again, Kevin"

& was told:

"If the control switches are really only operating 'functions' and not controlling the main power feed (in or out) directly then they can be 'any' switch that provides the required function. Only the 'power' and 'motor' cables carry high currents.
Use an isolator switch and a fuse for the power (from the battery) and connect the motor directly to the control unit. You could even use a large contactor to switch the power on/off (defaulting to off when power is removed) which would be easier to source than a switch at those ratings. The contactor itself would be controlled by a small switch. This would even allow you to fit an emergency stop button (big red mushroom) in the event of problems or even act as a 'dead mans switch' by virtue of a cord-operated switch to shut off power if the driver falls out etc.
The remaining control voltages are just that - control - and you can use any switch (such as those rated at 12V, 125V or 250V etc) as they carry minimal current."

I replied:
"Yup, that's kinda what I was thinkin'. Thanks

Then, in an effort to confirm this "you can use any switch for control circuits" claim, I posted/shared this info with a couple of other forums
& they totally freaked out!

I was:
...called names (won't even go there)
...told I'm being reckless ("if you love yourself or anyone else, you won't do this")
...got permanently banned from (1) forum (basically, for arguing)
...got my question thread locked on another forum (as, your question has already been answered)
...& even had my entire ~10 page discussion thread on yet another forum totally deleted

* NOT tryin' to bring any drama this way, just lettin' you'all know, how "touchy" of a subject this seems to be
...& that I do lots of research in many directions.

That being said, (important details) lets move on, this seems to pertain to our situation:

"Extra-low voltage (ELV) is an electricity supply voltage in a range which carries a low risk of dangerous electrical shock. There are various standards that define extra-low voltage. The International Electrotechnical Commission member organizations and the UK IET (BS 7671:2008) define an ELV device or circuit as one in which the electrical potential between conductor or electrical conductor and earth (ground) does not exceed 50 V a.c. or 120 V d.c. (ripple free). EU's Low Voltage Directive applies from 50 V a.c. or 75 V d.c."
https://en.wikipedia.org/wiki/Extra-low_voltage

So, it looks like if we keep our systems under 75VDC their considered ELV.
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Old 01-01-2019, 12:25 PM
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Default Standards

"There are various standards that define extra-low voltage."
Standards?
...ya, all electrical components should have established "standards"

Standard
1.a level of quality or attainment.
synonyms: quality level grade degree worth caliber merit excellence
2.an idea or thing used as a measure, norm, or model in comparative evaluations.
synonyms: guideline norm yardstick benchmark gauge measure criterion

If we can find/figure the standards that certain components (switches receptacles etc.) are manufactured to meet, it should help us "properly" match appropriate alternatives.

But, then it gets way more complicated because there is Underwriters Laboratories (UL) in the United States; Canadian Standards Association (CSA) in Canada; and European Norms Electrical Certification or ENEC in European countries
& then, there are also IEC International Standard (s)

Such as/for example:
"IEC 1058 standard applies to switches for appliances actuated by hand, by foot or by other human activity for use in, on or with appliances and other equipment for household and similar purposes, with a rated voltage not exceeding 440V and a rated current not exceeding 63A. It also covers the indirect actuation of the switch when the function of the actuating member is provided by a part of an appliance or equipment, such as a door."

...much more to come
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Old 01-02-2019, 09:43 AM
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Default Why not just use the right stuff?

One may ask, If the properly rated components are available, why look for or use anything else?
Some of the main factors include:
...cost (specialty stuff always costs more)
...availability (may already have stuff, like a a box of switches etc.)
...creativity (different styles, types or combinations for different situations)
...or functionality (just can't find a "properly rated" component in the right configuration or size for a certain situation)

An electric kart (vehicle) has many electrical components, take the Torsk kart for example: http://www.diygokarts.com/vb/showthread.php?t=38905

It has a (48VDC 1,000W) brushed motor matched with a YK31 (48VDC 1,000W) speed controller
...(4) 12V 12AH SLA batteries
...& uses a 48VDC 2.5A battery charger.

As for companion components it has:
...a throttle (Hall Effect switch) sends a signal to control speed (5VDC ~?mA)
...an on/off switch to switch the speed controller on/off (48VDC ~15mA)
...an on/off switch to switch the Amp/Volt meter on/off (12VDC ~50mA)
...a push button switch to activate the reverse function (5VDC ~?mA)
...a brake lever switch to activate the brake light (48VDC ~?mA)
...a circuit breaker total system protection & main power cut-off switch (48VDC 50A)
...a couple of other small fuses for the small power draw systems (48VDC >5A)
...& a charge port to connect the battery charger (48VDC ~2.5A)

Now, lets take a closer look.

We'll get to the on/off rocker/toggle type switches, but first lets discuss the reverse button.

To operate the reverse function, this circuit needs a normally "Off" (open circuit), momentarily "On" (closed circuit) push button switch.
(this switch is always in the "Off" (open circuit) position until the button is pressed then it's in the "On" position)

This means the system operates 100% (normally) with this button in the "Off" position. It's when this button is engaged (switched "On" to make contact) that it tells the speed controller that you want to operate the motor in "reverse". (turn backwards, when the throttle is operated)

This circuit (as shown above) operates @ 5VDC ~mA? (haven't tested yet to be exactly sure, but IMO probably >20mA)

I wanted to (& it would be super convenient If I could) mount the reverse switch into the top of the left steering wheel hand grip, but I couldn't find any DC rated switches that would fit.
(most DCV rated push button switches, I found, were for "big round" car horn (replacement) buttons (12VDC-low amp) or "super heavy duty" for engine starter (replacement) buttons.(12VDC-high amp)

Then, I remembered reading, a while back that Bob58o mounted a house "doorbell" button into the end of his mini-bike handle bars to use as a "kill switch". I thought that's a brilliant idea because the switch is normally off "open circuit" & when engaged "closed the circuit" it would "kill" shut the motor off.

Then I thought, that's exactly what I need, but they are probably only rated for AC voltage
(nope. I found that some house door bell systems operate by DC voltage but, that's another story)

Ya get the point, I figured that if a door bell switch, for a house, was adequate to use as a "kill switch" (& a perfect fit) on a minibike, why can't I use one to operate the reverse function on a go kart?

* Yup, I did it!
Did it work?- yes.
Is it proper?- were tryin' to/gonna find/figure that out.
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Old 01-02-2019, 10:28 AM
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Default

A switch is unlikely to ever be overkill..

AC and DC ratings are not necessarily related.. there is NO SUCH THING as a "rule of thumb"
The problem lies within material physics of the used contacting points.
and if and how much of an arc can be induced during the switching process.
(and the material being able to tolerate said spark w/o melting)
Some switches happily carry 10Amps @ 250V AC but no more than 150mA at the same voltage DC
Others carry 10Amps at 250V AC and do't care much about 2Amps 250V DC..

The single thing that you can rely on is the manufacturers DC rating.

And yes, DC switches are beefier than AC ones most of the time even slightly bigger
sometimes it's the points size, sometimes just the material.
But truth is.. for every possible voltage and amperage there is a matching switch you can buy and rely on.
ask digikey or mouser, not ebay

'sid

PS and when in doubt, series wire a fuse with whatever mA rating the switch should handle reliably... if it blows you'll still be safe
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Old 01-02-2019, 11:23 AM
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Functional artist- new guy here, some great info your putting out there. Im also building an electric bike at the moment and its been a lot of help reading through these posts. I came across a 22mm or 7/8 bar mount doorbell type switch (for reverse) for my build so Ill be watching to see how yours turns out. Heres the switch Im planning on using (was like $10 bucks) eBay.
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Old 01-02-2019, 12:46 PM
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Default Charging ports

Now, lets look at that last component, the charge port.

To get specific, this is the battery charger I have/use for my 48V karts:
https://www.ebay.com/itm/48V-Output-...ed7:rk:16:pf:0
Its rated 48VDC 2.5A & designed for use with lead acid batteries.
It has a regular 2-prong wall AC input plug, operates on standard 110VAC (house current) & has a C15 (male) DC output plug.

So, we need to find a matching/mating charge port to mount on the vehicle
...& also, connect to the battery pack, that can handle ~2.5A @ 48VDC

Searching around & doing research, it looks like these connectors come as C-13 (male) & C-14 (female) or C-15 (male) & C-16 (female) & both types seem to have the same ratings. (125VAC 16A/250VAC 10A)

It looks like the C-13 & C-14 connectors for home appliances with removable power cords, like computers & other small appliances.

Only appliances that get hot seem to come with or have the C-15 & C-16 connectors, like "kettle cookers" deep fryers & slow cookers. (& battery's/chargers too)

* The only visible difference that I see between the different types is a notch, which looks like it's designed to block/stop a C-13 (low temp rated) plug from being inserted into a C-16 (high temp rated) receptacle.

Since it came with a C-15, as a, DC output plug, it looks like my battery charger was designed to be used with a C-16 input receptacle
...but, 99% of these type receptacles, that are available, are of the C-14 style.
(which will plug in/work & are (electrically) rated about the same but, they just don't have the high temp rating)

* It looked/seemed like a C14 receptacle would work so:
Yup, I tried one!
Did it work?- yes.
Is it proper?- that's another thing were tryin' to/gonna find/figure out.

Here is more info on these receptacles.

https://www.ebay.com/itm/1PC-10A-250...1180:rk:5:pf:0

https://uk.rs-online.com/web/p/products/3521831

https://docs-emea.rs-online.com/webd...6b8152c07f.pdf

https://cpc.farnell.com/schurter/610...tab/dp/CN20000

http://www.farnell.com/datasheets/1968851.pdf
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Old 01-02-2019, 05:00 PM
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Quote:
Originally Posted by itsid View Post
A switch is unlikely to ever be overkill..

AC and DC ratings are not necessarily related.. there is NO SUCH THING as a "rule of thumb"
The problem lies within material physics of the used contacting points.
and if and how much of an arc can be induced during the switching process.
(and the material being able to tolerate said spark w/o melting)
Some switches happily carry 10Amps @ 250V AC but no more than 150mA at the same voltage DC
Others carry 10Amps at 250V AC and do't care much about 2Amps 250V DC..

The single thing that you can rely on is the manufacturers DC rating.

And yes, DC switches are beefier than AC ones most of the time even slightly bigger
sometimes it's the points size, sometimes just the material.
But truth is.. for every possible voltage and amperage there is a matching switch you can buy and rely on.
ask digikey or mouser, not ebay

'sid

PS and when in doubt, series wire a fuse with whatever mA rating the switch should handle reliably... if it blows you'll still be safe
Yup, I have to agree with (most) everything you just said.
Yes, it's always best to use components that are properly rated (by the manufacturer) for the task.

I also understand that AC voltage ratings don't easily "cross reference" with (or over to) DC voltage ratings, for many reasons. (design, housing materials, contacts materials etc.)

But, what if there isn't an "actual" manufacturer DC rating on a component? (example: C-14/C-16 receptacles)

I have found some info on "rerating" for different loads with a notice about "DC cross referencing":
"AC 250V Current rerating for different loads
Inductive Load: 5.6A
Lamp Load: 2.88A
Motor Load: 3.2A
Capacitive Load: 2.88A
Very Important Notice:
Ratings on the switch label are only for Purely Resistive AC load, for other types of loads please refer to the ratings above.DC load Current ratings are much lower than AC load,if you need to use this switch with more than 0.5A DC load,contact us for compatibility at first."

But, @ what voltage is that .5A DC load rating applicable? ...250VDC?

I guess what I'm tryin' to figure out is:
...how to tell if a (given) component/switch (built to certain standards, like having a 250VAC/16A rating) would be safe to use @ (lets "top out" the ELV max & say) ~72VDC & switching a max of ~2.5A of direct current?


* I'm also glad you brought up using a fuse, wired in series.

Again, with potentially using a C-14 or C-16 receptacle as a DC input to charge the battery pack as an example:

I have found there are plain C-14/C-16 type receptacles (~$2.00)
https://www.ebay.com/itm/1PC-10A-250...ZDk:rk:20:pf:0

...then, there are ones that have a fuse holder built into the housing (~$3.00)
(that would be perfect for adding an appropriate fuse to the charging circuit)
https://www.ebay.com/itm/1Psc-IEC320...S!-1:rk:1:pf:0

…others have an On/Off switch built into the housing (~$4.00)
(perfect for switching the port Off when not in use)
https://www.ebay.com/itm/IEC320-C14-....c100005.m1851

…& then, I've also seen some with both a fuse holder & an On/Off switch built right. (~$6.00)
https://www.ebay.com/itm/3Pin-iec320...lvP:rk:14:pf:0

...or even some of the 3-way combo units for as low as (~$.75)
https://www.ebay.com/itm/NEW-3-Pin-I...hrm:rk:19:pf:0
...just gotta wait til March to get 'em.

* …& they all look/seem to have the exact same 250VAC10A/125VAC 15A ratings.
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Old 01-02-2019, 07:57 PM
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Simple if there is NO DC rating on such component.. you CAN'T!

You could buy two and test one to know the limits for the other.. but you cannot just guess or calculate much less take anyone's fictive conversion rate and rely on that.

sparkarresting connectors are less critical than switches for the most part,
since any connection/disconnection process is what makes the contact fail..
once properly connected all you need to take care of is conductivity (low resistance)

Again:

skip ebay and crap and turn to people that actually know their stuff
like Digikey mouser RC Components and whatnot...
they all provide nice filters where you can set the voltage (ac or dc) and the curents needed and provide you with parts that match your query.
No keywordspamming, no false information (everything is backed up with manufacturer datasheets) and no fricking guesswork.

'sid
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Old 01-02-2019, 08:50 PM
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Here is some more info on these IEC 320 C-14 (3-way combo) receptacles
...I ordered a few different ones to inspect & test

It's a nice-n-compact panel mount unit that has a C-14 (female) receptacle, a fuse holder & a switch.

On the back it has (3) different ratings marked/molded into the housing.

The top one reads (10A 250V~)
...this ones probably the rating for the receptacle itself (it's at the top)

In the middle it also says (10A 250V~)
...this ones probably for the fuse contacts (it's in the middle)

The bottom one reads a little differently (250V~ 6.3A 2.5W)
…& this one is probably for the switch (it's at the bottom)
* This last one has different/lower ratings probably due to the fact that it is for a switch & that switch has to be able to "break" the flow of current.
Where as the other (2) components just have to be able to carry the current, NOT actually switch or "break" the flowing current.


I "really" like the idea of using a fuse to protect the charge port circuit.
...I didn't on the Torsk kart but, now I know that ALL circuits that carry current should/must be protected
...so, I'ma gonna fix that soon.

I also like the idea of being able to switch the charge port "Off" when not being used.

Becaues, after installing the simple C-14 receptacle on the Torsk kart I noticed the wide "open terminals" & thought:

What if someone (especially a kid) sticks their finger in there?
...could they get shocked?

What if someone (especially a kid) sticks something (metal) in there?
…& "Dead Shorts" the battery pack?

What if it just fills up with water?
…could water carry enough current to short the battery pack?

Wow!, I just kinda "freaked" myself out I gotta get that fixed pronto
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Old 01-02-2019, 11:10 PM
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Default

Quote:
Originally Posted by itsid View Post
Simple if there is NO DC rating on such component.. you CAN'T!

You could buy two and test one to know the limits for the other.. but you cannot just guess or calculate much less take anyone's fictive conversion rate and rely on that.

sparkarresting connectors are less critical than switches for the most part,
since any connection/disconnection process is what makes the contact fail..
once properly connected all you need to take care of is conductivity (low resistance)

Again:

skip ebay and crap and turn to people that actually know their stuff
like Digikey mouser RC Components and whatnot...
they all provide nice filters where you can set the voltage (ac or dc) and the curents needed and provide you with parts that match your query.
No keywordspamming, no false information (everything is backed up with manufacturer datasheets) and no fricking guesswork.

'sid
Yes sir, I have looked at some of the components & switches available on Digikey & Mouser.

I found a (plain) C-14 receptacle (~$7.00) rated 250VAC/DC 3A
https://www.digikey.com/products/en?...0003A000&v=495
...a C-14 receptacle with fuse holder (~$15.00) rated: 250VAC/DC 4A
https://www.digikey.com/product-deta...296-ND/4945166
…& also a 3-way C-14 receptacle, fuse holder & switch combo (~$22.00) rated: 250VAC/DC
Power Entry Connector Receptacle, Male Blades - Module IEC 320-C14 Panel Mount, Flange (~$22.00)
https://www.digikey.com/product-deta...303-ND/4945036
Detailed info/Data sheet:
https://en.tdk.eu/inf/30/db/emc_2014/B84776.pdf

* I (mostly) understand what your saying, it's just that ALL of these components are rated to handle 250VDC
...& were only discussing ELV systems (<75VDC)

That's quite a big difference in the amount of voltage a component is required to be able carry
...don't you think?

That's why I am trying to "narrow down" the requirements for this specific situation:
An appropriate/acceptable receptacle to use for connecting a 48VDC (~54VDC max) @ 2.5A &/or a 60VDC (~72VDC max) @ 2.5A battery charger to a battery pack.
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Old 01-03-2019, 06:56 AM
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Originally Posted by Functional Artist View Post
* I (mostly) understand what your saying, it's just that ALL of these components are rated to handle 250VDC
...& were only discussing ELV systems (>75VDC)

That's quite a big difference in the amount of voltage a component is required to be able carry
...don't you think?

That's why I am trying to "narrow down" the requirements for this specific situation:
An appropriate/acceptable receptacle to use for connecting a 48VDC (~54VDC max) @ 2.5A &/or a 60VDC (~72VDC max) @ 2.5A battery charger to a battery pack.
Sorry.. are you asking why a C14 powercord connector is rated for 250V and not just 60?
Seriously?

I'm sorry.. but that's like asking why e27 lightbulbs are not available in 12V DC as much

'sid
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Old 01-03-2019, 08:16 AM
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Originally Posted by itsid View Post
Sorry.. are you asking why a C14 powercord connector is rated for 250V and not just 60?
Seriously?

I'm sorry.. but that's like asking why e27 lightbulbs are not available in 12V DC as much

'sid
No,

If I understand this correctly, a C-14 power cord connector that has an IEC "standardized" rating of 250VAC 16A, it means that the C-14 connector has to be able to handle (up to) 16A @ (up to) 250VAC.

I am trying to figure out if (I guess theoretically) & why a "standard" C-14 power cord connector, rated 250VAC 16A, can handle 2.5A @ 48VDC
...&/or 2.5A @ 60V @ 2.5A

* I pretty much know they can handle 48VDC @ 2.5A because, I have been (naively) using C-14 connectors to charge my 48V karts, every since I've had 48V karts, with NO problems what so ever.
They never even got warm, I checked several times

I also have seen these simple C-14 connectors (they look to be the exact same) charge ports (connectors) available at many scooter parts stores, for use with their battery chargers.
They just call 'em House Battery Charger Connectors.
http://electricscooterparts.com/batt...onnectors.html

& they look to be available on all of the chargers that they sell, Lead & Lithium, their even available on their larger 60V & 72V chargers.

* I also called Electric Scooter Parts.com (1-800-908-8082) & asked if their #CNX 605 (3-pin) House Charger Port ($4.95) was the proper mating connector to use with their #CHR-72V2 5AHS 72V 2.5 Amp charger with 3-pin house plug ($159.95)?

They told me "yes it is"

Then I asked, if they had any info/DC rate data on these C-14 connectors or if they knew if they were "properly" rated for use with 72V systems?

They said, they don't have any DC rate data available but, these are the ones that they sell, for use with their battery chargers.

I am NOT tryin' to argue, just (hopefully) learnin' & tryin' to maybe confirm some info.
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Old 01-03-2019, 10:50 AM
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Originally Posted by Functional Artist View Post
No,

If I understand this correctly, a C-14 power cord connector that has an IEC "standardized" rating of 250VAC 16A, it means that the C-14 connector has to be able to handle (up to) 16A @ (up to) 250VAC.

I am trying to figure out if (I guess theoretically) & why a "standard" C-14 power cord connector, rated 250VAC 16A, can handle 2.5A @ 48VDC
...&/or 2.5A @ 60V @ 2.5A
...
Ahh I guess I see where your confusion comes from...
The CONNECTOR is a totally different animal than the SWITCH

The Connector (the C14 part) is actually able to handle up to 20Amps @ 250V DC
(according to the manual it's been tested to 1100 Volts DC @ 20Amps)
[B84771A0020A000 or B84771M0020A000] [M being the medical version]
as can be seen in it's datasheet:
https://en.tdk.eu/inf/30/db/emc_2014/B84771.pdf

The switch on the other hand is limited by the rocker switch inside itself.
https://en.tdk.eu/inf/30/db/emc_2014/B84776.pdf

And that again boils down to the contact points..
and the limits thereof.
that's why it is limited to 10Amps instead
[B84776A0010A000 or B84776M0010A000]

Both of which likely have the same spec connector internally (able to handle 20A w/o issues) and are just restricted by the switch's spark arresting ability.
Ac is self decoupling since by the nature of the current drops to actually zero twice per cycle (no volts == no currents )
for a very brief moment but enough to kill a growing arc.
DC however doesn't do such thing.. thus the arc keeps on growing for as long as it can..
so heat melting points.. welding shut or wearing off the points
to degrade..cause resistance, welding at the next switching cycle.
yadda yadda....

Unfortunately.. the switches have no DC rating that I can see in that datasheet..
simple reason for that is... C14 is actually MEANT for home appliances and wallpower (250V AC)

So we're back at the very same issue..
IF you pick a part that is designed for AC, you'll never get an ideal DC rating.
especially if we talk switches here.

switches in gernal are a PITA for highcurrent DC
(so much so, that it's mostly cheaper and more reliable to use a contactor or relais instead)

But assume you'll find small toggle/rocker switches that do have a DC rating...
(say EOZ Djet 10mm series)
you'll often find something like:
 Switch rating
Voltage Current
220 VAC 1.5 A
110 VAC 2.5 A
48 VDC 1 A
24 VDC 2.25 A
12 VDC 4.5 A

As you can see the higher the voltage the lower the amperage capabilities.
And that's part of the whole issue with arcing and points melting and shirt.

Oh keep in mind while this is a real world example switch, that those numbers are NO indicator for other switches!

'sid
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Old 01-03-2019, 03:58 PM
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At my job we use a lot of AC rated only switches on our 120/240VAC & 24DC powered products. I am also involved in the testing of our products. So I see firsthand the passing and failing of switches, motors, solenoids...etc. We also have many of our products listed under UL, so they have no problem with AC rated only switches being used with DC power, as long as it passes their tests.

It all boils down to what you are doing FA, trial & error. For example, I've seen 5A switches outperform 10A switches that were used in the same application & from the same manufacturer.

We of course test our products before being sent to UL for certification. As stringent as UL may seem, we cycle our products to 1Million cycles and they only cycle them to 250K cycles to meet their standard. Also, UL is a freaking monopoly
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Old 01-04-2019, 10:06 AM
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Originally Posted by Shep1970 View Post
Functional artist- new guy here, some great info your putting out there. I’m also building an electric bike at the moment and it’s been a lot of help reading through these posts. I came across a 22mm or 7/8 bar mount doorbell type switch (for reverse) for my build so I’ll be watching to see how yours turns out. Here’s the switch I’m planning on using (was like $10 bucks) eBay.
Hello & welcome

I am not familiar with that particular switch
...but, it should work fine

IMO & from my research, it looks like most any (decent) (12VDC or even 250/125VAC) switch should work to control the signal circuits, like the reverse function, on these speed controllers.

Because, it's just a ~5VDC signal circuit
...& it's only switching <1A @ that ~5VDC (probably way less than)
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Old 01-04-2019, 12:27 PM
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Default Apples & Oranges

Yes, connectors & switches are very different animals

Kinda like apples to oranges
...but, a bushel basket will hold/carry either one just as well.


I'ma gonna break it down a bit more. (mainly for my own knowledge)

From what (I think) I understand:
Conductors are (most) anything that "conducts" or carry's the voltage &/or amps/current in an electrical circuit. The wires &/or cables are usually the main conductors, in a circuit.

Connectors are basically conductors with "special powers".
They are designed to conduct current but, also be able to be separable, like wire connecting plugs & receptacles, sometimes repeatedly

Switches are also basically conductors too (while maintaining contact anyways) but, they have their own "special powers". They are designed to connect &/or break the flow of current in a circuit, when requested/at the "flip of a switch"

So in essence, receptacles such as the C-14 (&/or many of the other types) are basically conductors
...& IIRC for most conductors, it doesn't make much of a difference if its AC current or DC current running thru it (especially @ ELV levels)

Now, (concentrating on just the receptacle) let's expand this discussion a bit by comparing true DC rated receptacles with the AC (only) rated receptacles.

The AC rated C-14 "house hold" receptacles are rated to be able to handle (up to) 10A @ (up to) 250AC
...& The TDK DC rated C-14 receptacle is rated to be able to handle (up to) 10A @(up to) 250VAC (or) DC

But, in this (specific) application (connecting a 48V or 60V battery charger) we are only talking about ELV circuits (up to) 75VDC that will only ever carry ~2.5A

* I understand about having a nice safety margin (usually ~10%-20%)
...but, having that HUGE of a safety margin (for both amp & volt ratings) seems a bit unnecessary

Kinda like using 4g. battery cables (instead of 10g. wires) to supply power from the battery pack to (48V 1,000W) speed controller.

So, (in your opinion/hypothetically) how many amps should an average "house hold" C-14 receptacle with a 250VAC 10A rating be able to handle @ 48VDC?

...how about @ 60VDC?
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Old 01-04-2019, 04:41 PM
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Quote:
Originally Posted by Texan View Post
At my job we use a lot of AC rated only switches on our 120/240VAC & 24DC powered products. I am also involved in the testing of our products. So I see firsthand the passing and failing of switches, motors, solenoids...etc. We also have many of our products listed under UL, so they have no problem with AC rated only switches being used with DC power, as long as it passes their tests.

It all boils down to what you are doing FA, trial & error. For example, I've seen 5A switches outperform 10A switches that were used in the same application & from the same manufacturer.

We of course test our products before being sent to UL for certification. As stringent as UL may seem, we cycle our products to 1Million cycles and they only cycle them to 250K cycles to meet their standard. Also, UL is a freaking monopoly
Yup, that's kinda what I was thinkin'

If we can figure a "rough" DC Volt & Amp range for a potential ACV rated component
& that AC rated component is operated within those "rough/estimated DC parameters
& those parameters exceed the "specific DCV parameters" of a particular circuit.

There shouldn't be any problems

---------- Post added at 05:41 PM ---------- Previous post was at 05:15 PM ----------

Remember, on Star Trek (The next generation), Commander Data's answer when someone asked "how are you doing today"?
He would respond "operating within specified parameters".

That's where I'm coming from, with this, if we can accurately estimate the "specific parameters" of an AC rated component (were talking about conductors only NOT switches)
...& those "estimated parameters" meet or exceed the "specific parameters" of a DC circuit
...then, it seems to make sense (to me) that they should work together just fine.


* Yes, yes, I (now) know their are DC rated components available
...& I will certainly use them (if necessary)

** I am just doing all of this research because, I want to know "for sure" if I/we can "safely" continue to use a standard "house hold" C-14 receptacle (with only an AC rating) to charge the battery pack on my/our 48V & 60V electric karts.
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