Circuit tracer

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slect

Member
Location
Florida
I am having trouble locating a sub panel in a condo that was remodeled about 9 years ago.
I have an MDP with 4 3-pole breakers .. I have accounted for 3 of those sub panels panels but can’t locate the 4th..
It is labeled AV Panel.. The home theater has 2 racks that go dead when that breaker is shut off.. I can see the conduit in the theater ceiling but lose it about 10 feet away.
Anyway, my question is could someone recommend a good tracer that I can following the circuit/conduit thru the walls ?
I have tried lookin for false or removable panels in the theater but don’t see any .. Whoever hid this sub panel did a great job…
thx guys
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Is it possible that there is no panel, or have you confirmed that the conductors are different at each end?

That's quite a home-theater feeder, though you didn't mention the rating. Mine is "only" 120/240v 50a.
 
S

slect

Member
Location
Florida
The breaker is 125 amp. When shut off the following goes out..
All equipment in the theater , TVs in living room, office , bedroom automatic console lift , and rack in bedroom closet.
this is a 5 bedroom Penthouse….
I have the the breaker end , can’t find sub panel …
thx for responding
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Next question: Is the conduit you can see the feeder, and not branch circuits?

Just to ask: Have you looked behind every rack? Is there an attic or basement?
 
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slect

Member
Location
Florida
Seven delta , I got the Amprobe system. The directions said the receiver will not be able to pick up the
transmitting signal thru the metal conduit ,,, Does the ideal syste .?
Plan b is too attach a camera to majic stick and follow the conduit in the ceiling as far as possible. The camera sends the
picture to an app on the iPhone…. Some body hid this panel a little too good …
Thx for input
 
Fred B

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
Typical tracer might not work with conduit installed conductors as already stated above. Might be able to locate with an infrared camera. Might need to load circuit if things are buried deep to generate some heating on the conductors.
Did find one once that the sheetrocker rocked right over the panel, the only tell was the slight bump in the rock. Also found one in a closet, behind clothes rack, boxes and toys. Had to take rack down to open panel door, rack ran right across in front of panel door. So did you check all the closets? Also found a fuse box behind a kitchen cabinet.

Did or can you check other units? If this was a remodeled, unit I've seen where they didn't bother to change the electric source when downsizing or splitting a unit, and breaker was now in a different unit.
 
synchro

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
A suggestion is to use the Amprobe transmitter to drive a test signal current through the equipment grounding conductors (including conduit) that are running between the MDP and one of the branch circuit outlets powered by the "AV Panel" breaker in the MDP (with the subpanel in the middle of this path somewhere). You would do this by creating a closed loop with a separate wire that goes between the EGC at this outlet and the MDP, and where the two terminals of the Amprobe transmitter are connected between this wire and the ground bar of the MDP. The wire should be routed some distance away from where you think the conduit between the MDP and subpanel is located (e.g., put the wire on the floor if you think the conduit is running above the ceiling). That's so the signal flowing through the wire doesn't interfere with the receiver that you're using to trace the route to the subpanel.

Hopefully the above approach would allow you to trace the EGCs (including conduit if present) that are between the MDP and the branch outlet, with the subpanel located somewhere along this path. To determine where the subpanel is located along this route if you didn't already find it, you would need to repeat the above with another outlet that has a different EGC path to the subpanel (for example, on a different branch breaker in the subpanel). You would have to use your best judgement about what outlets would likely be on different branch circuits. If successful, you would trace a "Y" with the subpanel at the juncture of three paths. Other outlets could be used to get further confirmation of the subpanel's location.
If there's an isolated ground that goes through conduit, you would need to connect the wire to the conduit at the outlet and not to the isolated ground.
 
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garbo

Senior Member
slect said:
I am having trouble locating a sub panel in a condo that was remodeled about 9 years ago.
I have an MDP with 4 3-pole breakers .. I have accounted for 3 of those sub panels panels but can’t locate the 4th..
It is labeled AV Panel.. The home theater has 2 racks that go dead when that breaker is shut off.. I can see the conduit in the theater ceiling but lose it about 10 feet away.
Anyway, my question is could someone recommend a good tracer that I can following the circuit/conduit thru the walls ?
I have tried lookin for false or removable panels in the theater but don’t see any .. Whoever hid this sub panel did a great job…
thx guys
Click to expand...
Never had any luck tracing power that was feed in metal conduit no matter what brand tracer I tried. Years ago while working for a rich fortune 500 company they refused to purchase a circuit tracer for the Six electricians so we used a toggle switch wired to a plug that we kicked in to trip a 120 volt circuit. Did that one weekend and after looking thru halve of the halve millon square foot building asked one of the security guards that was there for a long time if he know about any hidden circuit breaker panels. He told me of one little what turned out to be a 6 or 8 circuit panel behind a large painting on a wall. I tried using a fiberglass fish tape to locate panels but always got stopped at first LB condulet it pull box. Couple of times found 100:amp panels inside of filled basement kitchen cabinets when they converted a house into a duplex apartment without getting any permits..Good luck .
 
grich

grich

Senior Member
Location
MP89.5, Mason City Subdivision
Occupation
Broadcast Engineer
LarryFine said:
To repeat myself:
Click to expand...
With the feeder de-energized

Watched a co-worker jump off a ladder years ago, with the fish tape sparking on the ladder after he let go. Good thing he was wearing leather gloves. Those gloves almost wrapped around my neck when I said "why didn't you flip off the breaker?" 😁

Fish tape in conduit makes a dandy racket. Ought to point you in the right direction.

I've found the destination of a stubbed conduit by taping a Sonalert to the open end of the stub, then walking around until I heard the beeping. I had a couple possible destination boxes opened up, which made hearing the beeping much easier.
 
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gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
220428-2106 EDT

The contents of my post were destroyed somehow. This website has fundamental problems from time to time.

What I was suggesting was --- put two different 250 W 120 V loads ( floodlights ) on two different parts of the circuit. This means one bulb on a portion beyond the "Y" point, and the other on a different portion.

At the source you have two times the current that exists near each bulb. Get a field intensity reding just after the breaker. Then follow that current to the point where the current drops to about 1/2. That is at least one point where there is paralleling. There may be a box at this point.

.
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
grich said:
Fish tape in conduit makes a dandy racket. Ought to point you in the right direction.
Click to expand...
It should make even more noise when it hits the inside of the hidden panel.

Doing this should be faster than any other method, not to mention cheaper.

Some of us seem to look for the most complicated ways to do some things.
 
S

slect

Member
Location
Florida
Guys
Thanks for all your input. The Amprobe circuit tracer I have will not detect the transmission signal thru metal conduit..
Fished a snake through the conduit and picked up a faint noise behind one of the permanent acoustic wall panels in the
home theater .. Found the sub-panel but the acoustic panel is lost forever …
Thx again ..
 
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