How many watts / amps for LED light bar?

[JethroB]

A poster once mentioned the great quantity of bugs a ROPs mounted light bar attracted. That would be a concern if I ever considered them. Any others with that issue?

 

[WranglerX]

Keep in mind Ohms Law..

Volts time Amps equal Watts....Or V x A = W

Or

Watts divided by Volts equals Amps... Or W / V = A

Voltage will always be a constant in calculation whether a 12 or 24 volt vehicle system or 120 volt shop lighting system...

Any lamp source that does not state actually electrical draw is not much help.... The "equivalent watts" or stated "lumens" as a relative description to light output, and may not have any actual relevancy for actually electrical draw....

Ohms Law Calculator

This free Ohm's Law calculator solves for any of the variables in the Ohm's Law equation using various units of measurement and gives out the solving steps.

www.calculator.net

 

[CoyPatton]

One note here that I believe is worth pointing out is that watts, amps and voltage are all electrical terms. They really do not describe brightness.
That is mot to dismiss the need to understand the importance of these electrical terms to the health of your tractors electrical system.
While watts of an incandesce bulb had a bearing on brightness back it the day, as florescent light became popular, the color of the bulb had more influence on thus than wattage.
Now with LED’s wattage has to fo with the start up power required and nothing to do with brightness.
Brightness is now discussed in terms of lumens. And is a more comparable measurement.
Hope this helps.

 

[ededic]

I just wired my refurbished curtis cab with LED lights and the factory cab lights, I used relays and switches as it would be done in the factory. I have used 10 amp fuses for any of the LED lights. I use 20 amp fuses on the wipers and original cab lights. The lights I have are SMD3030 chips emitting 6500K bright light and 3000K super yellow light, providing 120w and 12000lumen.

One thing I would think about is the new LEDs that offer not just the white but the amber light. My light bar that I had installed on the ROPS before the cab was so bright, no one could work in front or in the rear of the tractor without being blinded. I now replaced them with the multi mode LEDs that have Bright white, Amber, Bright white with Amber, White Flash, Amber Flash and Bright White/Amber Alternating Flash. I hooked up a momentary switch to the yellow wire on the lights and change them with a simple bump. The amber light is a nice bright soft yellow the illuminates and does not blind anyone great for working at night with people around the bucket and the back hooking stuff up.

Just a thought.

 

[WranglerX]

I just wired my refurbished curtis cab with LED lights and the factory cab lights, I used relays and switches as it would be done in the factory. I have used 10 amp fuses for any of the LED lights. I use 20 amp fuses on the wipers and original cab lights. The lights I have are SMD3030 chips emitting 6500K bright light and 3000K super yellow light, providing 120w and 12000lumen.

One thing I would think about is the new LEDs that offer not just the white but the amber light. My light bar that I had installed on the ROPS before the cab was so bright, no one could work in front or in the rear of the tractor without being blinded. I now replaced them with the multi mode LEDs that have Bright white, Amber, Bright white with Amber, White Flash, Amber Flash and Bright White/Amber Alternating Flash. I hooked up a momentary switch to the yellow wire on the lights and change them with a simple bump. The amber light is a nice bright soft yellow the illuminates and does not blind anyone great for working at night with people around the bucket and the back hooking stuff up.

Just a thought.

View attachment 696673

A sort of yes, here.... A lot of LED come in different color temperatures expressed in kelvin and I believe 5500/6000 k. is equivalent to sunlight... Anything with larger number tend to be into the bright blue spectrum, where lesser numbers tend to be on the softer brown tones.... The brighter blue spectrum as actually harder on the eyes than the softer shades of brown...

 

[CobyRupert]

Do we know if wattage stated is the actual consumed wattage (Wattage= Volt x Amps) of the lamp, or a measure of its light (lumen) output when compared to an incandescent lamp (of that wattage)?

The voltage of the system might vary between 12.0-14.6V.

Incandescents are like heater elements that glow. LED’s are non-linear devices. Meaning their impedance (resistance) depends on the voltage it’s being measured at, or said another way: the voltage across it. (Sidebar: Most materials act like heater elements when it comes to conducting electricity (unless you coil them or make electrostatic plates). Using ohms law you can determine a materials resistance. Once measured, it’s close to being set like stone. Doesn’t matter what voltage you used to measure. Comparable to a pipe you’re conducting water through. Changing the pressure doesn’t change the physical characteristics of the pipe. It’s still a 1” pipe! LED’s are more like a flexi-hose than a pipe. Mankind has really been able to exploit the non-linear characteristics of LED’s, diode’s (transistors), etc..
..I digress)

“Efficacy” is the measure on how efficiently a lamp produces light from the energy supplied. It is usually measured in lumens/Watt. Incandescents are really poor at this. LED’s are really good.

Light bar vs. floodlight: If they produce the same lumens, then it’s just a matter of how the light is distributed. (Wide, narrow, up, down, etc..)

Remember nothing is free: Just as lighting makes some areas brighter, it makes other areas darker. Lighting is sometimes more about perception than illumination.

 

[SmallChange]

Do we know if wattage stated is the actual consumed wattage (Wattage= Volt x Amps) of the lamp, or a measure of its light (lumen) output when compared to an incandescent lamp (of that wattage)?

The voltage of the system might vary between 12.0-14.6V.

Incandescents are like heater elements that glow. LED’s are non-linear devices. Meaning their impedance (resistance) depends on the voltage it’s being measured at, or said another way: the voltage across it. (Sidebar: Most materials act like heater elements when it comes to conducting electricity (unless you coil them or make electrostatic plates).

Yes, the question about whether it's actual consumed wattage is a good one! I just finally ordered some small light bars, but it was actually a bit challenging to get this question clear on many of the products I was choosing between. The old incandescent bulbs were convenient to choose based on wattage when you really were interested in choosing the brightness, but newer more efficient lights throw this not-very-correct method of picking them way off.

About lights being like heater elements that glow: there's one very big difference, that impacts electrical resistance and power supply issues. Heater elements are almost always made with an alloy like Nicrome that was designed to have a nearly constant electrical resistivity over all temperatures. But incandescent light bulbs are not, because they operate too hot. Instead, they use elemental metals, almost always tungsten. A single element metal generally has a resistance that is proportional to the absolute temperature, which means its resistance when running is 10X higher than it is when off. If you measure the cold resistance, you'll predict ten times more current draw than it will actually use when it is on -- except during the fraction of a second when you first turn it on before it comes up to temperature. In fact, you need special circuit breakers to handle this very short term inrush of current. That's what they mean by "tungsten rated" on a breaker.

And about LEDs being non-linear devices: the literal LED device itself is very nonlinear, yes. If you buy an LED component from an electronic parts wholesaler you must deal with this. But the products we buy in lamp assemblies have power conditioning circuits to manage this. In fact, if you look on Amazon for 12 V LED light bulbs, you will see even the little bulbs have tiny circuit boards visible inside them, which take care of all that. It may be hard to guess what such an assembly looks like when you measure voltages and currents for it.

 

[Pete O]

I'd be having a long hard think about what you want the lights for; i.e. what you need to illuminate. Lighting up the working envelope of a FEL, for instance, is very different to needing to avoid wildlife on an outback road when travelling at 120km/hr (here it's kangaroos and emus, for you maybe black bear?!). The LED lightbars I use on my vehicle for that purpose are fantastic but would cause a public nuisance and a traffic hazard if I was using them on my tractor around my small property. Anyone working with you, be they on the ground or on other machines (like when harvesting into a towed bin), will be looking into your lights at least some of the time. A few well-placed LED work lamps of modest output would probably more suited to the purpose, and well within the 10a draw.

 

[Helogabals]

I have recently gone trough that
At the end bought this osram

1. it's "combo" beam
2. 30 W = 2... 3 A
3. 1 Lx = 360 m
4. not so big, really tough body. on my ROPS already was holes, this ledbar fit there without drilling anything

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[Williy]

No trouble with bugs at they don't like the
amber lights

willy