24 volts on ground

[FREEBALL]

OK I have a question. I am installing a circuit for radio chargers. Anyway the circuit is entering a conduit already installed which is roughly 50 years old. The main service coming into the building is 120/240 delta w/ neutral for 120 volt loads, which was the norm that many years ago. Anyway this particular circuit originates in an old panel, 60ft away, that is fed from a disconnect some 150 ft away, which in turn is fed from a 3ph 120/240 delta w/neutral (4 wire). The feed is an old 4/3 armored clad cable. The armored clad is carrying the ground. The conduit is also interconnected to a newer installed panel that is wired w/ 2/3&4 SER cable coming from the before mentioned 3 ph. panel. While I disconnected power for a circuit that was deadended in order to remove it, I found 24 volts from dead circuit to ground now I did not have time to investigate further.

I am concerned because there are a lot of electronics in the building now, which weren't the intention 50 yrs ago, but with my Hx. in the past with the office area of this building, I found arcing from ceiling grids to ground, which I fixed by removing an old panel that was in the ceiling, of all places. What are some of your thoughts on this type of situation. Now I thought about stray currents but with the arcing I observed before I am leaning towards neutral/ground bonding issues, not to mention an already overloaded neutral due to neutrals connected to electronics and the fact the neutral is coming from a delta system:?.

Thanx in advance

 

[rlundsrud]

it sounds like an induced current from a circuit that's in the same cable or conduit.

 

[GoldDigger]

it sounds like an induced current from a circuit that's in the same cable or conduit.

It is much more likely an induced voltage, probably capacitively coupled.
If that is the case it will not be able to drive significant current, and a wiggy or low input impedance voltmeter will show zero volts.
If the OP can pull significant current from the wire to neutral or ground than it needs to be investigated.
The other arcing symptoms suggest a compromised neutral or improper bonding along with leakage somewhere.