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# Activity Stream

• 3 Days Ago
Power Factor Calculator - Enter circuit information to get power factor and reactive power values along with capacitor size for correction to desired PF. TCC Calculator - Generate trip times and tolerance ranges for LSIG trip units.
1 replies | 1380 view(s)
• 4 Days Ago
I found an app called Quizlet that helped me learn the device numbers. I created a prep quiz in the app for called ANSI Device Numbers that is open to everybody. I t really helped me with memorizing the the device numbers. There are other tests on there that will help also. Good luck.
8 replies | 4399 view(s)
• 5 Days Ago
We are pleased to announce the upcoming release of a new app for Android designed specifically for test technicians in the field. The TestGuy Android app features the most popular references found on testguy.net along with new information and unique calculators. Get the best of TestGuy in your back pocket anytime, even when offline! Here is just a short...
1 replies | 1380 view(s)
• 5 Days Ago
This gives a good list of relays to know and how to test each element specifically as to what they sense. https://testguy.net/content/290-Protective-Relay-Protection-Element-Tests
8 replies | 4399 view(s)
• 1 Week Ago
Impedance must be calculated for each component (i.e. the capacitive impedance, inductive impedance and resistive impedance) to calculate the total reactance of the circuit. Without the frequency, you cannot determine the reactance of the circuit as inductors and capacitors react differently at different frequencies. This page explains it alot better...
9 replies | 1745 view(s)
• 1 Week Ago
Well, that throws a wrench in the works but, the question was not looking for the impedance of the circuit but simply the reactive component of the circuit at 60 hz. While the math is correct about the phase angles, I'm not sure what the exact wording of the question was or what 4 choices were available, wish I knew.
9 replies | 1745 view(s)
• 1 Week Ago
I did not know this. Thank you for the information!
9 replies | 1745 view(s)
• 1 Week Ago
Thank you for the catch. I see on the formula sheet that they have the formula for Z and you are very correct. Z= the square root of R squared plus (XL-Xc) squared
9 replies | 1745 view(s)
• 1 Week Ago
I disagree with the above post, the math is almost good. Only problem I see is you cannot just add Capacitive Impedance and Inductive Impedance together, remember the phase angles are up to 180 degrees apart. ZT2=XR2+(|XL-XC|)2 So, since there is no XR ZT=(236-76)=160 Ohms
9 replies | 1745 view(s)
• 1 Week Ago
Yes the math does work out. However as stated, two inductors in parallel of equal value = 1/2 the inductance of both and 2 capacitors in series of equal value, likewise = 1/2 the capacitance of both. No need for the math. Whiskers
9 replies | 1745 view(s)
• 1 Week Ago
Your math all works out to me. A time saver when performing this and from my experience with similar questions on the test is that they will use two identical, in this case capacitors in series and reactors in parallel, values. When this is the case the calculated value is half of one of the identical capacitors. Capacitor Example: Look at Rofo42's...
9 replies | 1745 view(s)
• 1 Week Ago
I think you're correct up to this point. Looking at the equation sheet, it should be XL - XC So doing that I get 160 ohms. I'd be willing to bet that both 160 and 312 are possible answers on the test.
9 replies | 1745 view(s)
• 1 Week Ago
21, 24, 25, 27, 32, 43, 49, 50, 51, 52, 59, 67, 72, 79, 81, 87 I would at least have these memorized. Start paying attention to the schematics laying around at any job or device numbers posted on switchgear covers, relays etc. It's actually pretty important to have these in your head. Also, its equally important to have a general idea of how each device...
8 replies | 4399 view(s)
• 1 Week Ago
He said no dice. You would still have to sit the NICET exams
5 replies | 5166 view(s)
• 1 Week Ago
Very interested to find out a definitive answer.
5 replies | 5166 view(s)
• 1 Week Ago
My buddy sits on both committees, I will ask him.
5 replies | 5166 view(s)
• 1 Week Ago
The MAC test is now an optional test in both the ATS and MTS. Several utilities require it , we do it on every VCB we touch.
9 replies | 5516 view(s)
• 1 Week Ago
We have some customers that require it on Magneblast bushings but usually not the norm.
9 replies | 5516 view(s)
• 1 Week Ago
I'll take a stab at this... Capacitors in series are found using the reciprocal or product over sum method. This gives a total of 10 uF. (20*20 = 400. 400/40=10) Capacitors in parallel are added together. 10 uF + 25 uF = 35 uF Capacitive Reactance (Xc) = 1 / 2*pie*F*C ( 2 * 3.14 * 60 * .000035 = .013188) 1/.013188 = 75.82 Xc = 76 Inductors in...
9 replies | 1745 view(s)
• 1 Week Ago
Thank you for the kind feedback, this typo has been corrected.
2 replies | 20615 view(s)
• 1 Week Ago
This question appeared on the NETA III exam. Find the total reactance in this circuit. I distinctly remember it because it was the very first question to hit me and I said "Gee thanks alot". I wasn't quite ready for it.
9 replies | 1745 view(s)
• 1 Week Ago
The only breakers I have used power factor testing for is oil field breakers. On vacuum breakers we just use the over potential test for vac integrity and insulation integrity. Things like this are interesting though. I'll have to do some research now.
9 replies | 5516 view(s)
• 1 Week Ago
I wonder if that is more of a factory test? The arrestors I've tested we have just single shot them with the Doble in GST mode. Leakage to ground and go to the next one.
4 replies | 1188 view(s)
• 2 Weeks Ago
As usual, your information is extremely valuable and written so that electricians, technicians and maintenance personnel can follow right along. I call it "from the field" approach, not attempting to talk over our heads or trying to impress someone. I did notice that you said "racking mechanisms are sometimes referred to as leveling mechanisms". I believe...
2 replies | 20615 view(s)
• 2 Weeks Ago
This is what I found after a Google search: Power Frequency Sparkover Test: This is routine test. This test is conducted using a series resistance to limit the current in case a sparkover occurs. The arrester has to withstand at least 1.5 times the rated value of the voltage for five successive applications. The test is generally done under dry and wet...
4 replies | 1188 view(s)
• 2 Weeks Ago
Hipot seems like a good idea. If you figure it out please share.
4 replies | 1188 view(s)
• 2 Weeks Ago
I need to assemble a device to operate a 120VAC 1/8hp fan motor triggeded by one of 2 120VAC switching devices. One device will be a standard IR motion sensor; the other, a countdown single pole switch. I am assuming that most motion sensors are not equipped to handle voltage on the load side (supplied by the countdown timer) when the motion sensor is...
0 replies | 1573 view(s)
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