View Full Version : What test set or method you are using for testing turns ratio on CCVTs?
scottxclark
November 5, 2016, 03:40 PM
Can any of you tell me what test set or method you are using for testing turns ratio on CCVTs? Are you guys applying a high voltage to the high voltage terminal, and measuring the secondary, or are you using a test set? My understanding is a standard TTR test set will record too high of an error due to the voltage decay in the capacitor stack. Vanguard's CTV-765 seems like a simple and fast test set. Any feedback is appreciated. Thanks!
Sanjayo
November 6, 2016, 09:00 AM
Most simple method I think is using a power factor test set as a power supply to the HV terminal and measure the secondary voltage.
lester mcmanaway
November 6, 2016, 07:20 PM
Most simple method I think is using a power factor test set as a power supply to the HV terminal and measure the secondary voltage.
totally agree with Sanjayo, just did some a few months back, 80kv-120v I believe. we put 10kv on the high side with our omicron cpc100/td1 and measured 15v on the low side
randywright
November 7, 2016, 11:01 AM
Could you use an AC hipot if you don't have a power factor set?
lester mcmanaway
November 7, 2016, 02:53 PM
Could you use an AC hipot if you don't have a power factor set?
Never tried that... not sure honestly. I don't see why not.
randywright
November 7, 2016, 03:18 PM
Hipots usually trip out on very low levels of current.
Never tried that... not sure honestly. I don't see why not.
lester mcmanaway
November 7, 2016, 03:57 PM
Hipots usually trip out on very low levels of current.
Very true. Yep, not likely you would be able to use a hipot. Good call. Depending on the ratio, I've used just a small power source.
trn8ochaser
November 15, 2017, 11:17 AM
I personally use an M4100 to apply 10kV to the top and measuring at the bottom with a voltmeter. However, this will either be at 57 or 63 Hz, which I've recently been concerned about effecting the accuracy.
NWILLJR1020
November 16, 2017, 09:16 AM
Can any of you tell me what test set or method you are using for testing turns ratio on CCVTs? Are you guys applying a high voltage to the high voltage terminal, and measuring the secondary, or are you using a test set? My understanding is a standard TTR test set will record too high of an error due to the voltage decay in the capacitor stack. Vanguard's CTV-765 seems like a simple and fast test set. Any feedback is appreciated. Thanks!
We use a DOBLE M4000 power factor test set
wooddy
January 16, 2018, 01:24 PM
I personally use an M4100 to apply 10kV to the top and measuring at the bottom with a voltmeter. However, this will either be at 57 or 63 Hz, which I've recently been concerned about effecting the accuracy.
wooddy
January 16, 2018, 01:30 PM
We use a DOBLE M4000 power factor test set i use this method as well, to deal with the 57 to 63hz question, go to instument settings and change from automatic ramp up to manual ramp up, then use the arrow keys to bring the ccvt to 10kv, read voltage on the secondary, this will give u the ratio as well as be a stable setting at 60hz
wooddy
January 17, 2018, 11:50 AM
go into the insturment settings of the m4100 and change the ramp up from automatic to manual, then use the page up and page down keys to raise the voltage to 10kv on the top terminal of ccvt, read the voltage on the secondary, this will eliminate the machine from ranging from 57 to 63hz but rather give you stable readings at 60hz,
Chipperk
June 26, 2018, 07:45 PM
Most simple method I think is using a power factor test set as a power supply to the HV terminal and measure the secondary voltage.
I use the power factor test set. Read the ratio off the secondaries.
hy3533
July 5, 2018, 09:03 PM
go into the insturment settings of the m4100 and change the ramp up from automatic to manual, then use the page up and page down keys to raise the voltage to 10kv on the top terminal of ccvt, read the voltage on the secondary, this will eliminate the machine from ranging from 57 to 63hz but rather give you stable readings at 60hz,
Very helpful. Thank you for the info.
baccuskt
June 4, 2019, 05:39 PM
Can any of you tell me what test set or method you are using for testing turns ratio on CCVTs? Are you guys applying a high voltage to the high voltage terminal, and measuring the secondary, or are you using a test set? My understanding is a standard TTR test set will record too high of an error due to the voltage decay in the capacitor stack. Vanguard's CTV-765 seems like a simple and fast test set. Any feedback is appreciated. Thanks!
I believe Omicron makes a special test set for this. I have used their CPC-600 (not sure I remember correct number) to test these also. You could also probably use a variac although it depends on the ratio if you can get a high enough voltage to measure secondary.
ChuckEnglish8
July 11, 2019, 08:39 AM
I use the power factor test set. Read the ratio off the secondaries.
same here
FadakHamady
November 13, 2019, 09:21 AM
Can any of you tell me what test set or method you are using for testing turns ratio on CCVTs? Are you guys applying a high voltage to the high voltage terminal, and measuring the secondary, or are you using a test set? My understanding is a standard TTR test set will record too high of an error due to the voltage decay in the capacitor stack. Vanguard's CTV-765 seems like a simple and fast test set. Any feedback is appreciated. Thanks!
Use CPC100
backpack96
October 3, 2020, 09:48 AM
I personally use an M4100 to apply 10kV to the top and measuring at the bottom with a voltmeter. However, this will either be at 57 or 63 Hz, which I've recently been concerned about effecting the accuracy.
Great that you are performing a voltage ratio tests as a TTR will not provide the results.
Have never seen where line frequency modulation mode will affect the voltage. You can change the test mode to line sync reversal and the frequency will remain at 60 hz.
The line frequency modulation test mode was a great idea to eliminate electro-static interference from the overhead power lines in a sub.
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