What and how do we know what IS ‘Better’?
or
It’s all in our heads, or is it?
Part 23-A ASCC test results, Wait, What?
As I stated in Part 22, this topic is somewhat dependent upon what I mentioned about fuses and current flow.
And
ASCC is ALL about current flow.
So what is
ASCC?
It stands for Available Short Circuit Current.
Available Short Circuit Current is an electricians proof of performance test of the ‘health’ of electrical power systems. It seems to be used mostly with branch circuits found in commercial buildings and homes. And it’s mostly used as a diagnostic tool to determine if there are any ‘problems’ in a branch circuit and can be used to troubleshoot where the problems may be found.
This test essentially calculates the ability of the circuit under test, to deliver near instantaneous amounts of current during a hot-neutral ‘dead short’ (aka. “bolted fault”).
ASCC test results are calculated by dividing the line voltage by the circuit’s line impedance, (by adding the Ω of the hot + neutral wires together).
This test is useful in that it determines how much power the selected branch circuit can deliver, but doing so without even the possibility of tripping the circuit breaker.
Note: a circuit breaker trips, not by over heating then melting a wire like a fuse does, but by building enough magnetic energy in a coil to ‘trip’ its internal ‘breaker switch’. This process takes more time and energy than a fuse and so behaves differently. And one of these behavioral differences is the ability of a breaker to pass large amounts of current, for a short duration. This salient fact is of interest to us because of this ability to deliver short duration high amplitude current bursts, without tripping (circuit breaker) or self destructing (fuse), and this behavior specifically matches the needs of our diode bridge switched power supplies quite well.
But for our uses,
ASCC tests will tell us how much current can be dumped into the power supply, VERY quickly, like in mS, before that coil in the circuit breaker trips.
This ability to dump current quickly becomes much more significant when we delve into fuses and how they respond to current and also what criteria the manufacturers use to rate their fuses.
This amount of current flow is the ‘raw’ power that the duplex receptacle we are plugged into can deliver when asked for.
So the question then becomes how much current can be ‘delivered’ in a very minuscule amount of time, coincident with the question of how much is ‘enough’? And is moar always better?
So the next series of related experiments were aimed at generating further data.
Namely, how much current is available at the duplex receptacle we plug our gear into?
And
Can a power cable alone make any measurable difference?
And
Does the amount of available current have any correlation with the SQ of our systems?
Note: I originally saw this test performed by Caelin Gabriel of Shunyata Research in one of their online videos. I then researched the tool he used and found a less expensive and readily available tester to use for my experiments.
And since I have been tweaking/modifying my dedicated branch circuit that feeds my audio system, it was easy to also measure the ‘standard’ branch circuits in my house to see what, if any, differences could be found with them as well.
And as I continued to generate test results, a pattern emerged from the data, as I dove into the deep end of this pool while using the EXTECH CT-70 Circuit Analyzer to perform the ASCC and other relevant tests. And I performed multiple tests over many days as a means of verifying the readings.
The comparison between my house’s built in power distribution vs. the dedicated lines I added (computer & audio), did reveal differences between these different branch circuits. And then there is the progression of the measurements starting with the standard appliance cord (
AppCord see below), and my DIY G-1 & G-4 cables and and also my Shunyata (Python & A-D) and Marigo cables, and a cable I used as a reference.
So this is but the first of several such data extractions from all of the data I collected. And the thing is since I couldn’t get this Analyzer calibrated I must assume that the absolute values of these test result numbers are suspect and the rated 2.5% +0.2% accuracy as listed by EXTECH is ‘close’ enough. And really all I am expecting to see are trends and ∆ change comparisons.
The layout I came up with displays all of the data I collected under the conditions as listed.
This first graphic is a ‘narrow view’ of just 2 locations in my house, the
bathroom CFGI receptacle and a standard duplex receptacle in the wall in the living room.
I’ll start by filling in much of the significance and meaning behind this layout and add more later as we drill further down into all of this.
So starting in the upper left hand corner is
Cable # and then as we move right in that row we see
REF cable (twice).
Note:
REF cable means the supplied by EXTECH 14gauge
Stubby (12”) appliance type cable. This is a good choice because it’s short and 14gauge. These 2 factors will be more relevant later.
Then next we have, (as we move down the left side one row)
Cable Name and in that row we see
Stubby - 14g, G-4-r - 13g, and AppCord - 18g.
These are the 3 cables I used during testing at these 2 initial locations (see next row description).
The
Stubby has been explained above and the
AppCord is a standard appliance power cable that comes with our gear.
But the
G-4-r is my DIY 4th generation cable with rhodium connectors that has been cryo treated and cooked.
Next row down is,
Location all equipment was running which shows 2 locations,
bathroom CFGI and
Standard duplex recept post & pilr rev pol.
The
bathroom CFGI is self explanatory but the “
Standard duplex recept post & pillar rev pol” means a standard in the wall duplex receptacle being fed by post and pillar wiring that is reversed polarized (hot - neutral reversed and has no ground connection).
And these tests were made with a normal household electrical load running my computer and audio system etc., (nothing was shut down to ‘help’ the readings).
And this condition of running with the normal electrical load while making these tests applies to all of the measurements I took.
Next row down is where we start listing test results, starting with,
Voltage tests L-N (line to neutral) voltage measurement
units in
AC Volts N-G (neutral to ground) this should be at or near 0.3 volts, the minimum resolution
Peak (not rms voltage)
Then we have,
Voltage Drop 12a These readings are indications of this circuits performance where a 5% or greater
units in
% 15a drop in voltage during the test is considered ‘poor’, and where the Analyzer ‘loads’
20a the circuit with 3 levels of current ‘demand’.
Next is,
Impedance Z-L (Hot Ω) These are calculated resistance readings that are a
units in
Z-Ω Z-N (Neutral Ω) reflection of the amount of resistance that each of these 3
Z-G (Ground Ω) wires have.
And finally the whole enchilada,
Kilo-Amps ASCC These are calculated results showing how much current is
available based upon the
ASCC test procedure.
Now what does any of this mean you ask?
Well a more complete analysis, let alone any conclusions, will follow, in Part 23-B thru E of this ‘Better’ series.
But for now lets just say that the post and pillar wiring in my house is ‘poor’ and so the ‘need’ for dedicated runs to power my computer and my audio system was sorely needed.
And this is a good place to start and establish a baseline set of readings to use to compare with other tests.
JJ
End Part 23-A
Next up Part 23-B Deeper down the rabbit hole we go
