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Equi=Core Hum & Other Issues

I’ve owned a Core Power Tech Equi=Core 1800 for 6 months. Recently the transformer has started to hum inside the chassis. It happens when components are on and also when sources are powered down. The transformer hum is intermittent. It ranges from multiple times per day to 3 or 4 days without any hum. I never had DC on my dedicated lines before, so I picked up a Klein Tools AC/DC tester... https://www.kleintools.com/catalog/electrical-testers/electronic-acdc-voltage-tester-12-240v-ac-15-2...
and when plugged into wall receptacles it indicated overload. Line voltage is steady at 122VAC and always has been.
What am I doing wrong, and how should I test for DC on the power line?

I discovered another problem when testing the Equi=Core duplex receptacles; they indicate inverted polarity. All house outlets measure correct polarity.
I’m looking for some assistance in diagnosing this hum. I’m not sure if it’s due to DC offset or if the torroid itself is vibrating in its mounting.

I know this is becoming a long thread, but I must mention that the Equi=Core now trips the breaker at the panel when powered on. It trips several times in a row, eventually allowing power-up. This is a 20A dedicated line from a subpanel which I’ve had for years.
Any advice is much appreciated.


128x128lowrider57
uberwaltz's avatar
uberwaltz
13,381 posts
 
Jim
I would say the 20a breaker is toast, although that has already been stated.
However working in large industrial application electronics and electrical installations we get plenty of breaker trip issues ( sub contractor bad wiring, incorrect wiring, shorted cables etc).
Generally we replace ANY breaker once it has tripped 3 times in rapid succession.
Not advocating that as any sort of "golden rule" but have seen plenty of 20a breakers( we use a lot of that size in our heating panels) trip with just 15a of load after a number of rapid fire trips.
Pays to be prudent especially when the customer has just dropped 3 to 5 million on his latest toy and expects trouble free production... lol.
lowrider57's avatar
lowrider57 OP
5,417 posts
 
Uber, I plan on having the breaker inspected and replaced. I've had multiple trips in succession. 
Thanks.
grannyring's avatar
grannyring
6,466 posts
 
DC blockers are cheap to buy and build. One can be put inside your conditioner as I have done in my BPT Balanced isolation tranny. It quieted my BPT Conditioner and my Clayton Audio amp’s transformer. No need to spend many hundreds for the Deep Core to solve a DC issue.

I populated this board and wired it inside the unit. The board has inputs from your IEC and outputs to your tranny.  You can even buy several finished options:
https://www.atlhifi.com/shop/assembled-pcbs/fully-populated-dc-blocker-pcb/

Even tiny, tiny amounts of DC can cause the tranny to buzz like crazy and it does change throughout the day in intensity. That is normal. Replace your breaker and get a dc blocker installed.


falconquest's avatar
falconquest
1,108 posts
 
  Uber, I plan on having the breaker inspected and replaced. I've had multiple trips in succession.

I'm no expert but I do know there are two quality levels of circuit breaker. There is a "home" version and a higher quality version. Ask your electrician for the best breaker. The price may be a little more but since they are overall pretty inexpensive, it's not a place to save money. They may insist the lower priced unit is adequate for your home but this is not a circuit to run a .......hairdryer. ;-)

jea48
4,408 posts
 
@Al, (almarg),

Thanks for the kind words.

I find it’s best just to ignore his posts.

Jim
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