 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
96.238.214.112
In Reply to: RE: well I am not ashamed to say I learned something today posted by jimmyjames on February 11, 2009 at 12:10:43
The Balanced power systems that have gone through compliance testing(UL, TuV, ETL) will have GFCI outlet for safety due to Neutral side is not bonded to ground. Look at the web site of the Balanced power makers.
Follow Ups:
The National Electrical Code says it is verboten, and why would you want to plug anything audio into that GFI outlet. That would not stop me from building or using one but code compliance or lack thereof needs to be understood. Not sure how BPT gets away with it.
Most balanced power supplys are made for the pro audio/video market. Hospital power is a whole nuther issue but uses the same type of transformer design.
The BPT type device in residential application could be interpreted as some sort of add on power filtering device or even a piece of consumer electronics and not interpreted as powering the whole house which would be a code violation. That is certainly how I would interpret it but AHJ's are a narrow minded bunch and a balanced power device such as the BPT does represent a shock hazard if you were to use it for residential lighting. Nobody should but then again nobody should use a gasoline powered push mower as a hedge trimmer...
"E pur si muove...And yet it moves"
"The BPT type device in residential application could be interpreted as some sort of add on power filtering device or even a piece of consumer electronics and not interpreted as powering the whole house which would be a code violation." That is the way they can get UL/TuV/ETL approval, it is not meant for the whole house. You can see company such as Equi=tech, Furman for example
Has nothing to do with, whole house or not.
======================
(1) The system is installed only in commercial or industrial occupancies.
(2) The system's use is restricted to areas under close supervision by qualified personnel.
Article 647.
Panamax and Furman balanced power units are UL and TuV. They can be verified by requesting the Certificated from them.
> >
Quote from Link below:
"Description
Designed for the most critical, ultra-low noise installations, the IT-20 II can supply 20 amps of Balanced AC power for recording studios, broadcast stations, or video production facilities. To understand the incredible need for clean noise-free AC power, it's important to note that today's sophisticated studio equipment features tremendous dynamic range. Most of the signal content that defines high resolution such as harmonics, instrument timbre, high frequency extension, spatial cues, and fast transient attacks in audio are inherently low in signal level. Further, when AC noise is induced into audio processors, pre-amplifiers, microphones, powered monitors, computers, and mixing consoles these all important low level signals are distorted or masked. Once signals are masked there is no way to retrieve the lost content. Advanced AC filtering is critical when audio or video resolution is at stake. With Furman's IT-20 II, for the first time you will hear audio content and see video images as they were meant to be - pristine. Add to this our SMP non-sacrificial surge suppression, E.V.S. protection, Linear Filtering Technology (LiFT), and laboratory grade digital voltmeter and you will be assured that AC noise and surges are a thing of the past."
========================
Says nothing about home use.......
> > > "the IT-20 II can supply 20 amps of Balanced AC power for recording studios, broadcast stations, or video production facilities."
link
Not UL listed....
Safety Agency Listing: C-ETL .... from specs.
Might be fine in the UK but not here in the US, jmho......
What matters is the agencies that your state 'recognizes'. Your state fire marshal can give you a list of them. UL is only one. I talked to ours many years ago about the issue and I can't remember just what others were recognized but I think TUV was the one I was asking about and it was OK.
Regards, Rick
http://www.panamax.com/Training/Resources/SafetyCertification.aspx
The article does not say if a balanced power system is Listed for use in a residential occupancy. The article only relates to safety testing.
Kind of like an off the wall example of a gas generator having a safety UL listing and then going onto say because it is Listed it could be used inside a home. The listing is given for the intended use......
Is the intended use of a 60/120Vac balanced power system safety Listed for use by the general public in their home?
I sent an email to Jerry Hoopes at Panamax asking him if a 60/120Vac, balanced power, system is listed for use in a residential occupancy.
I will post Mr Hoopes response, if he responds to my email.
Jim
you can also send an email to either Panamax or Furman customer support.
> >
I guess they are saying, hey look at us we do the same thing as balanced power but without being balanced. I don't think that is possible.
The NEC is subject to interpretation by you, me, the AHJ, the insurance companies, UL, etc. My interpretation is that a consumer electronic device such as a BPT box is a consumer electronic device and has the markings and the GFI required by NEC, etc. An AHJ (electrical inspector) is never going to see a BPT box during a residential electrical inspection. My "opinion" on the insurance company part of it is that whatever box you have, if it causes a fire, better have a UL, ETL or some 3rd party testing agency label on it or there will be problems.
If a balanced power transformer in a box solved some sort of audio/video problem for me or transformed the sound of my system, then I would install one in a heartbeat. I have played around with a small one and it hasn't done anything for me positive or negative. I have some older LC circuit filter boxes (MIT) and they do work, in my system, to great affect.
Also, not sure how this would be interpreted but there are lots of multichannel amps that use a balanced power transformer in them. Of course they don't have receptacles built into them to plug in appliances or other consumer electronic devices.
"E pur si muove...And yet it moves"
The NEC is subject to interpretation by you, me, the AHJ, the insurance companies, UL, etc. My interpretation is that a consumer electronic device such as a BPT box is a consumer electronic device and has the markings and the GFI required by NEC, etc. An AHJ (electrical inspector) is never going to see a BPT box during a residential electrical inspection. My "opinion" on the insurance company part of it is that whatever box you have, if it causes a fire, better have a UL, ETL or some 3rd party testing agency label on it or there will be problems.
NEC 647 needs no interpretation.......
647.1 Scope. This Article covers the installation and wiring of separately derived systems operating at 120 volts line to line and 60 volts to ground for sensitive electronic equipment.
647.3 General. Use of a separately derived 120-volt single phase 3 wire system with 60 volts on each of two ungrounded conductors to a grounded neutral conductor shall be permitted for the purpose of reducing objectionable noise in sensitive electronic equipment locations, provided the following conditions apply:
(1) The system is installed only in commercial or industrial occupancies.
(2) The system's use is restricted to areas under close supervision by qualified personnel.
(3) All of the requirements in 647.4 through 647.8 are met.
647.7 Receptacles.(1) All 15- and 20-ampere receptacles shall be GFCI protected.
(2) All receptacle outlet strips, adapters, receptacle covers, and faceplates shall be marked with the following words or equivalent:
WARNING- TECHICAL POWER
Do not connect to lighting equipment.
For electronic equipment use only.
60/120 V 1ph ac
GFCI protected
======================================================I have not seen any proof that any Listed testing lab has approved a 60/120V separately derived grounded power system for use in a residential occupancy. I have read where the equipment has been safety tested. But I have not read anything that says Article 647.3 is waived and the unit is approved for home use.
If a balanced power transformer in a box solved some sort of audio/video problem for me or transformed the sound of my system, then I would install one in a heartbeat.And that would be your choice..... And if for any reason you or a family
member were to be injured from your decision that will be on your shoulders.But if a manufacture, or dealer, represents the unit as "safety listed approved" for in home use and it turns out the unit is not...... Then jmho, take a copy of NEC 2008 Article 647 with you to the lawyer's office....
Edits: 02/16/09
sell them all day long to residential based consumers. Evidently their lawyers and insurance companies think their product is safe and that they have legal legs to stand on.
As to the code, it is interpreted and misinterpreted every day by AHJ's and others. I have been an electrical engineer involved in the design and construction of residential, commercial, industrial and medical facilities for 25+ years. Manufacturers sit on the code committees and push thru revisions and additions that suit their agendas. It didn't use to be that way but it is now and has been for some time. Some municipalities stopped adopting new code back in the 70's and their is still a movement to reject the NEC and adopt a best practices or standards in lieu of NEC code compliance.
I won't debate the safety of balanced power transformers. There is an inherent shock hazard if misapplied. I will however debate the necessity and interpretation of the all mighty NEC. There is good, safe, well engineered/designed electrical systems and then there is "code compliance". Cheers!
"E pur si muove...And yet it moves"
Jim,NEC 647.1 (Scope) outlines the requirements for separately derived 120V L-L / 60V to ground systems. The key term here is 'separately derived'. Note that the term "Balanced Power" is not defined nor used within NEC.
Per NEC 100 (Glossary), Separately Derived is defined as:
"A premises wiring system whose power is derived from a source of electric energy or equipment other than a service. Such systems have no direct electrical connection, including a solidly connected grounded circuit conductor, to supply conductors originating in another system."All Panamax and Furman products include a solid/direct ground connection back to the panel through the premise wiring and therefore do not fall under the classification of separately derived and the requirements of NEC 647.
All Panamax and Furman products are evaluated for safety by OSHA accredited Nationally Recognized Test Labs (NRTL) including Underwriters Laboratories, Intertek Testing Services (ETL) and TUV. The safety standards applied in the test and evaluation state that products shall additionally comply to the requirements of NFPA 70 (NEC) so compliance to NEC has been considered in the evaluation.
It is my understanding that the requirements in the NEC are for 120V/60V systems installed near the service panel and that distribute power as part of the premise wiring rather than point-of-use products such as ours. Given that we have been granted safety certification on these products by multiple NRTLs reinforces that conclusion.
If you have any additional questions, please do not hesitate to contact me directly.
Best Regards,
Jerry Hoopes
Engineering Manager
Panamax / Furman
(707) 766-2316> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
-----Original Message-----
Sent: Friday, February 13, 2009 7:09 AM
To: Jerry Hoopes
Subject: Balanced AC power system for use in a residential occupancies.Jerry,
Article 647 of the NEC states that a 60/120 volt, balanced power, system
shall only be permitted for use in commercial or industrial occupancies.
647.3 also requires the system use be restricted to areas under close
supervision by qualified personnel.So my understanding of NEC 647.3 is that a 60/120Vac system can not be used
in a residential occupancy.So am I correct that cord and plug balanced power systems are not Listed for
use in residential occupancies?Would appreciate your comments.
Regards,
Jim> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > .
Edits: 02/13/09
you can also send an email to either Panamax or Furman customer support.
http://www.intertek-etlsemko.com/portal/page/cust_portal/ITK_PGR/OUR_SERVICES_PG/ELECTRICAL_SAFETY_TESTING_PG
http://www.intertek-etlsemko.com/portal/page/cust_portal/ITK_PGR/DOCUMENTS_PROD_PG/ETLvULmatrix.pdf
I was at the Menlo park lab many times for compliance testing.
CETL is the independent testing agency with testing uniform to UL testing requirement.
Learn here:
http://www.crownaudio.com/amp_htm/certifmarks/certifmarks.htm
There is ETL testing lab in Menlo park.
The ETL Listed Mark is an alternative to the CSA and UL marks.
ETL Testing Laboratories has been conducting electrical performance and reliability tests since 1896. Intertek Testing Services (ITS) acquired ETL from Inchcape in 1996. ITS is recognized by OSHA as a Nationally Recognized Testing Laboratory (NRTL), just as Underwriters Laboratories (UL), Canadian Standards Association (CSA) and several other independent organizations are recognized.
ITS tests products according to nearly 200 safety and performance standards. The ETL Listed Mark and C-ETL Listed Mark are accepted throughout the United States and Canada when denoting compliance with nationally recognized standards such as ANSI, IEC, UL, and CSA.
This certification mark indicates that the product has been tested to and has met the minimum requirements of a widely recognized (consensus) U.S. product safety standard, that the manufacturing site has been audited, and that the applicant has agreed to a program of periodic factory follow-up inspections to verify continued conformance.
If the mark includes a small US and/or C, it follows product safety standards of United States and/or Canada, respectively.
Furman consumer version of the balanced power products: IT-REF7i, IT-REF15i, IT-REF20i. Panamax M7500 Voltage regulator + Balanced power. You can contact the company and request the certificates of compliance.
Furman also make pro equipment for studio such as IT-20II series.
Post a Followup:
| FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
||||||||||||||
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
