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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
jea48
4,266 posts
 
New service drop.
New meter socket.
New service entrance conduit and wire from meter socket to a new electrical panel.
(Including breakers). 
System grounding up date as needed.   
Electrical permit.

$1900..... That’s a good price.


Jim

lowrider57's avatar
lowrider57 OP
5,393 posts
 
@jea48
I wanted you to see the new installation. And I was wrong about conduit; code does not require it.

https://ibb.co/tzhyY6B

No more transformer hum.


jea48
4,266 posts
 
@ lowrider57

Glad to hear the new electrical service solved your hum problem.

As for the service entrance cable the electrical contractor installed.
Yes, it meets NEC, Article 338 of the code. And it is obviously approved for use by the AHJ (Authority Having Jurisdiction) in your area. The AHJ has the final say.

In the Capital City, metro, and surrounding suburbs cities in my State conduit is required for the electrical service. I’m not sure if any counties or cities in my state allows service entrance cable use for an electrical service. Though I do not know that for a fact.

Jim
lowrider57's avatar
lowrider57 OP
5,393 posts
 
I decided to install a whole house surge protector; a Square D to mate with my new service panel.
https://www.amazon.com/dp/B00CONA1OQ/ref=cm_sw_r_other_apa_i_x2a.EbGRB0EEQ

The instructions state that a 2-pole 20 amp breaker is required. OK, fine.
Now here's what I don't understand; if the surge protector has its own breaker wired to hot, neutral, ground on both phases, how is it going to absorb a spike before other circuits? Won't a surge trip other breakers as well as the surge protector?
There is no point of least resistance.
 
@jea48 
Feel free to comment.


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