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

Pictures are worth a thousand words......

Especially this one.....
https://ibb.co/qpQnYf5

Your service entrance drop is a cable. It is not a conduit with wire installed in it as I imagined.

It appears to me rain water is entering between the outer sheath of the service cable and the weather proof strain relief connector on the top of the meter socket. My guess is the rubber bushing, (or possibly, depending on the age of the connector, Oakum Packing Material), that is supposed to seal the service cable and the metal connector from allowing water from entering the meter socket is shot, deteriorated, allowing water to enter.

A band aid that may stop/help from rain water from entering the connector, therein the top of the surface mounted meter socket is to apply a good quality pure silicone caulking around the service cable and the weather proof strain relief connector.

Clean the cable with a dampened dish soap and water washcloth at least a couple of inches above the top of the connector and the entire top of the screw down cap/nut of the connector. Remove any loose debris that may be laying between the cable and the inside of the connector. Rinse off the soap with a slightly water dampened clean washcloth. Repeat as necessary to remove all dirt and soap. Repeat process if needed to get all surfaces clean. Allow to completely dry several hours. Surface areas must be 100% dry.

Apply the pure silicone caulk around the cable where it enters the connector throat, opening. Make sure you force, inject, as much silicone into the top of the connector between the cable and the connector as possible.

Finish off forming the silicone product using your finger. You want the silicone caulk to cover the top nut of the connector so the water will shed down the side of the connector.

Next using your finger slightly form, taper, the silicone caulk up all around the cable. Do not leave any globed pockets for water to puddle. You want the finish product to look like cone.

(To stop the silicone from sticking to your finger, as you form it, slightly moisten the tip of your finger with water as you form the silicon.)

Jim.
https://ibb.co/qpQnYf5

Looking at the picture again it looks like the back of the connector may be buried slightly in the outer stucco cement finish. Hard to really tell from looking at the picture.

If you want to get a good water tight seal you may have to chisel away some of the stucco to expose the back of the cable and the back side of the connector.

Use a small chisel and a small hammer... Take your time.... BE CAREFUL! Do not damage the outer sheath of the service cable.

Jim.
@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.