Now I know why you want and need a sub panel. If you have the money you may want to consider another option, an isolation transformer with an electrostatic shield like that of a Topaz. Feed the transformer with 240V, transformer output 120V. The output would then feed a small panel by a main breaker. Do you have a space near your equipment for such?
Showing 6 responses by jea48
I asked you questions about distances. Why do you need, want, a sub panel? Is your equipment a long distance from your main service panel? You mentioned the sub would be 120/240V, are you planning to feed the 120V audio branch circuits from each line to neutral. Best to feed audio equipment connected together by ics from the same line. L1 or L2, not from both. If you agree, why not wire the sub 120V only? If you would, finish answering the rest of my questions. Jim |
Square D QO MLO load center. Breakers plug in. Better, more money, Square D NQOD. Bolt on or plug in breakers. Bolt on breakers are better. Panel can be ordered with plated copper buss. Most of todays panels have aluminum buss. Example of prices for the NQOD http://ecatalog.squared.com/catalog/173/html/sections/08/17308006.html HD sells the Square D QO panels and breakers. Do not buy the Square D Home Line brand. ==== >What is the make-up of your Audio System? >What size of wire are you planning on feeding the sub panel with? >What is the distance the sub panel will be from the main panel? >How far will the loads, receptacles, be from the sub panel? >Will the sub panel be strictly 120V, or 120V/240V? >Will the dedicated branch circuits be NM-B, (Romex trade name), or will they be installed in conduit? >Are you planning on hiring an electrical contractor for the install? |
I agree with Lak in regards to the size of the transformer, 5KVA. http://www.surplussales.com/Transformers/IsolationXmers.html Note the 5KVA Xentek Extreme for $1595.00 used. |
Can you please fill me in with the benefit of the isolation transformer. With an isolation transformer like the Topaz or the Xentech Extreme: >Low capacitance coupling between the primary to secondary windings of the transformer. >Electrostatic shielding between the primary and secondary windings. In a nutshell, all the crap, EMI noise, RFI, and anything else you can think of on your AC mains will not cross over to the secondary of the transformer. The secondary is isolated from the primary. |
I might start with the subpanel first and leave enough main feeder wires for future upgrade if I decide to add the isolation transformer later on when save enough dought. If you are thinking down the road you may install a transformer then I would install a 120/240V feeder. The problem I see with your situation is the distance from the main panel to the loads, 125 feet...... Jmho, unless you feed the sub panel with at least #4 awg cu I do not believe you will realize any benifit from your audio system. Still terminate the feeder at the main panel on a 2P60 amp breaker. You could get by with a #6 awg cu equipment grounding conductor. How tough would it be to run a 1" EMT conduit? 3 #4awg THHN cu / 1 #6 awg THHN grd. So in theory is the transformer will keep the secondary voltage constant and clean. No power conditioner is needed for the audio systems. Somewhat more constant, voltage fluctuations on the primary side of the xfmr will be half that on the secondary side. Clean yes, though some guys also install another small iso xfmr for digital loads. This helps stop the digital noise from traveling back on the power cord of the digital gear and reentering the analog gear. Nobody ever said this hobby was cheap.... Jim |