Powering on 10 x 250w at once from one socket.

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George2324

Well-Known Member
Abiqua said:
fuses are current limiting as well and much cheaper.....
sorry meant to replyto @George2324
Click to expand...
But a fuse will blow if you go above that current.

We know the current could reach 15A due to inrush current.
If we use a thermistor instead of a fuse the device will attempt to draw 15a of inrush current but the resistance would be high on startup due to cooler temp. Keeping the amps down below 2A when the current continues to drAw through the thermistor for 5-10 seconds the heat will be hot enough so that the normal current draw that is required flows stopping the inrush
 
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George2324

Well-Known Member
The fuse will blow however we know that inrush current will always be above the fuses rating. So will blow the fuse every time?

Why would we need a resettable switch?

The thermistor on startup is at room temp and high resistance the start up current is limited due to this high resistance the thermistor heats up and then has no resistance and normal flow occurs.

Led driver turns off starts to cool down thermistor and 12 hours later comes back on when thermistor has reset back to room temp
 
DaveInCave

DaveInCave

Well-Known Member
George2324 said:
The fuse will blow however we know that inrush current will always be above the fuses rating. So will blow the fuse every time?

Why would we need a resettable switch?

The thermistor on startup is at room temp and high resistance the start up current is limited due to this high resistance the thermistor heats up and then has no resistance and normal flow occurs.

Led driver turns off starts to cool down thermistor and 12 hours later comes back on when thermistor has reset back to room temp
Click to expand...
But you don't know if the fuse will blow.
Again, the Amperage is not only parameter that is important. It is also important for how long this amperage will flow in the component, be it the wires, fuses, circuit breakers or LED driver. Nothing burns instantly. If the inrush current will be above the limit 2 micro seconds and decrease to working current immediately, then things will work ok.
You can't really know without trying. But when you do try, do it safely so you don't kill yourself, or worse, other people if something fails.
 
Abiqua

Abiqua

Well-Known Member
George2324 said:
The fuse will blow however we know that inrush current will always be above the fuses rating. So will blow the fuse every time?

Why would we need a resettable switch?

The thermistor on startup is at room temp and high resistance the start up current is limited due to this high resistance the thermistor heats up and then has no resistance and normal flow occurs.

Led driver turns off starts to cool down thermistor and 12 hours later comes back on when thermistor has reset back to room temp
Click to expand...
big ifs....you size the fuze accordingly aka slow blow fuse and what guarantees thethermistor from coming back on inadvertantly, again? thats the problem...you need a thermistor that will immediately heat up to provide resistance, and a lot because its inrush and then go near zero resistance (which is near impossible for Ntcs) and then on top of that, depending on the thermistor it might affect the ac sine as well....
it happens. thats why i suggested reviewing code. read that at least a bit beforeattempting these things
 
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Abiqua

Abiqua

Well-Known Member
this a really good article from rod ar ESP
essiantially it is a soft start circuit for power amps, but works here too....also explains the difference and how to choose a resistor / thermistor in greater detail....

http://sound.whsites.net/project39.htm


maybe @stardustsailor will grace us and help further.....maybe he can explain the methods he is currently using ......which seems to have replaced the timer offset board you built in 2015?
 
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George2324

Well-Known Member
Abiqua said:
big ifs....you size the fuze accordingly aka slow blow fuse and what guarantees thethermistor from coming back on inadvertantly, again? thats the problem...you need a thermistor that will immediately heat up to provide resistance, and a lot because its inrush and then go near zero resistance (which is near impossible for Ntcs) and then on top of that, depending on the thermistor it might affect the ac sine as well....
it happens. thats why i suggested reviewing code. read that at least a bit beforeattempting these things
Click to expand...
I think you didn't understand the point of the thermistor?

You don't need it to immediately heat up.

It provides HIGH resistance at ROOM temp.
So when the device first turns on before wire has heated up from electricity the first initial second of inrush it provides high resistance. The continuos electricity for more than a few seconds will increase temp of wire and the resistant will be 0.

Obviously if you are turning the device on and off every 5 minutes the wire won't have cooled and it would trip your breaker.

But if you are turning on and off ever 12 hours the thermistor will have cooled down and when you turn them back on the thermister will be at ROOM temp and HIGH resistance
 
Abiqua

Abiqua

Well-Known Member
George2324 said:
I think you didn't understand the point of the thermistor?

You don't need it to immediately heat up.

It provides HIGH resistance at ROOM temp.
So when the device first turns on before wire has heated up from electricity the first initial second of inrush it provides high resistance. The continuos electricity for more than a few seconds will increase temp of wire and the resistant will be 0.

Obviously if you are turning the device on and off every 5 minutes the wire won't have cooled and it would trip your breaker.

But if you are turning on and off ever 12 hours the thermistor will have cooled down and when you turn them back on the thermister will be at ROOM temp and HIGH resistance
Click to expand...
good luck with that! which thermistor have you chosen.....because i get completely what you are trying to accomplish but you need heat for resistance...finding an ntc with a room temp coefficienct and high current!....just use a resistor vs the thermistor and save yourself hassle
 
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nevergoodenuf

nevergoodenuf

Well-Known Member
I don't know about any other driver, but what I have notice with HLG's, with my kill-a-watt meter, is a soft start. Even with 8+ amps on the meter, the amps never spike and wattage gradually increases. Maybe the Kill-a-watt meter doesn't register the spike or the driver takes care of it.
 
Abiqua

Abiqua

Well-Known Member
nevergoodenuf said:
I don't know about any other driver, but what I have notice with HLG's, with my kill-a-watt meter, is a soft start. Even with 8+ amps on the meter, the amps never spike and wattage gradually increases. Maybe the Kill-a-watt meter doesn't register the spike or the driver takes care of it.
Click to expand...
interesting...i will have to see for myself

you probably are running mutiples of high wattage HLGs? correct @nevergoodenuf
good comparison for the OP
 
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George2324

Well-Known Member
That list says you can only have one hlg-320h-c driver per 16a breaker?

That's only 300w. If that's the case how on earth can LEDS ever be practical
 
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George2324

Well-Known Member
I had a 60a sub panel installed specifically for LEDS.

60a x 220-230v = 13800w
The breaker is a b version 60a
I was planning on using 8000w led and the rest for a couple of pumps...
 
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George2324

Well-Known Member
I could put multiple sub breakers within my sub panel...

My incoming main circuit board has the 60a breaker leading to the sub panel.

The sub panel currently has a 32a breaker and a 16a if I split these breakers up into multiple 8a breakers would it solve the problem or would I have the inrush current still flowing through the sub panel and then tripping the 60a main breaker
 
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