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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
lowrider57's avatar
lowrider57 OP
5,417 posts
 
@jea48 
Yes Jim, I see now that it's a cable. But isn't that a vertical  conduit that is attached to the box near the roof? It's fastened to the wall by brackets and ends where the cable turns and travels to the meter?

I have a 2nd contractor coming to look at it.

Have you ever seen an installation like this? All the attached homes have the same hookup.


lowrider57's avatar
lowrider57 OP
5,417 posts
 
@jea48 
Jim, I'm not planning to do this work myself. There's the issue of the age of these parts plus their unknown condition. There may be multiple areas of damage to the cable run. And some of the brackets are loose or broken.

 I couldn't open the meter lid, but not only are the contacts corroded, the entire box needs replacement. I'll take a pic once the electrician opens it.
And yes, there is stucco surrounding the cable.

jea48
4,484 posts
 
@lowrider57

If it were me I would have the electrical service replaced. It looks like it is well overdue.

How about the electrical panel? How old is it?
How about the branch circuit wiring?
Is it time to do a rewire?

Jim.
lowrider57's avatar
lowrider57 OP
5,417 posts
 
@jea48 ,
I plan on having the entire outside cable run plus meter lid replaced. The cable from meter to service panel was inspected and is ok.

Service panel is an older unit, the previous owner had about 80% of branch circuits replaced. It's easy to spot these...new breakers and cables. The old wiring runs to low current draw areas such as bedrooms, light fixtures. I had my electrician strip wires and organise the panel to keep an even load on each leg. 

I extended the service to include a subpanel with (2) 20A lines, 12/2 Romex, hospital-grade duplexes.
8' ground rod off main panel with second ground rod from subpanel. Most of the homes are grounded to plumbing.

uberwaltz's avatar
uberwaltz
13,381 posts
 
Am I missing something here?
Surely all of this should be on the electric company provider to make good and safe?
Here if I was even to look at anything on the incoming side of my main panel JEA would likely have me hung, drawn and quartered!
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