Hdr 68 30 Joule
Kristin Klodzinski
The joule is named after James Prescott Joule. As with every SI unit named for a person, its symbol starts with an upper case letter (J), but when written in full, it follows the rules for capitalisation of a common noun; i.e., joule becomes capitalised at the beginning of a sentence and in titles but is otherwise in lower case.[7]
At the second International Electrical Congress, on 31 August 1889, the joule was officially adopted alongside the watt and the quadrant (later renamed to henry).[9]Joule died in the same year, on 11 October 1889.At the fourth congress (1893), the "international ampere" and "international ohm" were defined, with slight changes in the specifications for their measurement, with the "international joule" being the unit derived from them.[10]
In 1935, the International Electrotechnical Commission (as the successor organisation of the International Electrical Congress) adopted the "Giorgi system", which by virtue of assuming a defined value for the magnetic constant also implied a redefinition of the Joule. The Giorgi system was approved by the International Committee for Weights and Measures in 1946. The joule was now no longer defined based on electromagnetic unit, but instead as the unit of work performed by one unit of force (at the time not yet named newton)over the distance of 1 metre. The joule was explicitly intended as the unit of energy to be used in both electromagnetic and mechanical contexts.[11] The ratification of the definition at the ninth General Conference on Weights and Measures, in 1948,added the specification that the joule was also to be preferred as the unit of heat in the context of calorimetry, thereby officially deprecating the use of the calorie.[12] This definition was the direct precursor of the joule as adopted in the modern International System of Units in 1960.[citation needed]
I got a BR1500LCD APC ups for my game PC and adore it. (* _index.cfm?base_sku=BR1500LCD&tab=models*) and I was thinking about buying another to use with my xbox 360/ps3 HDTV ETC Or the new model I saw of it *( _index.cfm?base_sku=BX1500G) BX1500G* I assume it is the updated model. The 800va UPS I got somewhere cheep from another maker just don't cut it with my HDTV/ps3/xbox 360 set up it cant power them enough.
So looking I just noticed the Joules rating on both is a rather tiny around 340 Joules. Is that really enough for a somewhat costly $199 Ups to have? It's not a ultra high end model but it is not a $99 entry level either. I have seen some cheeper models from APC and others with higher Joules ratings and APC's $30 surge protectors seem to have higher Joules ratings.
I mean really Is that enough to provide at least decent protection?
Am I going to have to start plugging surge protectors into the UPS sockets and hope one stops a really large surge? I try to unplugg all my junk around thunderstorms as a rule when I am home but I am not always at home and I like to leave somethings on sometimes or have too leave them on is 340 joules going to at least give me a small chance of safety here?
Basically with surge protectors, surge protection is their primary feature so surge protection is beefed up as much as possible. With the UPSs, the primary function is to provide runtime and be a battery backup. Surge protection is an added feature of that but the surge protection in the UPSs still meets the specs of UL1449 certification.
also, on some surge protectors and UPSs, you may see eP joule ratings versus just joule ratings..in regards to that..
APC uses the eP Joule Rating because we do not simply 'absorb' the surge like some other surge products might. Our products are designed to redirect the surge back to ground instead of absorbing it and incorporate a let through voltage, which is the maximum transient voltage the attached equipment will be subjected to above the normal RMS voltage. Any remaining voltage is redirected to ground.
The reason we even list the eP rating is for comparison with our competitors products. If we just listed the standard Joule rating, it would in most cases be lower than the competitors, because we aren't relying on absorbing the impact with a MOV, we're redirecting excessive voltage away from your equipment and safely back to ground.
From my understanding, we come up with the eP Joule rating by performing real world tests with both our equipment and the competitors. Based on these results, we can see how many Joules of absorbtion our units are equivalent to.
hope this helps
The joule (J) is the derived SI unit of energy quantity. One joule represents the work exerted by a force of one newton acting over a distance of one meter in the direction of that force.