[James Tanner]

Hi All,

Based on all the discussions about power receptacles on the Torus Power Isolation products I thought we should start a new topic on this.

There really seems to be a lot of confusion on what in fact a  "3 prong U ground"  USA style power receptacle is and what plugs are certified for 240 voltages.  I am going to post some pictures which will give us an overview of the differences. 

The concern I have here is that some people may be using what they think is an authorized certified 240 Volt US style receptacle on their gear when in fact that is not the case at all -(which is a serious fire and safety issue!) . The British, German and IEC320 type receptacles we currently use on the Torus are in fact Certified 240 volt receptacles.

james

[James Tanner]

Hi All,

Pictures from my gallery on the different plugs (I still haven't figured out how to download pictures)

http://www.audiocircle.com/index.php?action=gallerylastup&cat=0&pos=2

When you click on the link you will see the NEMA 5-15 and 5-20 (certified for 120 volt 15 and 20 amps) then click on the forward arrow at the top right and it will go to the 6-15 and 6-20 (certified for 240 Volt 15 and 20 amp).

As far as I can figure out these are the only CERTIFIED "US STYLE" receptacles available. 

james

[Occam]

When you have the image from your gallery, left click on it, hit properties, and copy the url in between the open image-close image code you'll get by clicking the second icon on the second row of the reply screen.

PS- there are also standardized NEMA locking plugs and outlets, for both 120 & 240vac, which I've never seen used in home av.

[James Tanner]

Thanks Occam- much appreciated.

james

[smerlas]

The receptacle type, conductor sizing for both the branch circuit and cord (or pendant) is regulated in the US by the National Electrical Code (NEC).  Oversized conductors and or cords are OK.  The plugs are supposed to be configured such that higher current devices can not be connected to smaller circuits resulting in overcurrent situation (tripped breaker).  When devices rated at 20 amps have their plug replaced to connect to a 15 amp standard duplex receptacle the branch circuit capacity can be exceeded, resulting in at best a tripped breaker or worse overheating of conductors / fire.

All are cautioned against replacing circuit breakers and receptacles without knowledge of the wire size and total current load on the breaker.  The load at the panel box should be approximately 75% of the branch circuits capacity.  The current wiring may not be rated for 20 amps.

If in doubt check with an electrician.  The length of the run, proximity to kitchens etc. all effect what the NEC says regarding conductor size and circuit capacity.

The cord ends are no different in theory than an electric range of electric clothes dryer.  The different cord ends prevent 120volt devices from being connected to 240v volt and and from larger current draws items to smaller current circuits.

[James Tanner]

HI Smerlas,

Thanks - So what do you think is going on overseas where some power conditioning products are using USA U-ground 120 volt receptacles with 240 volt gear?

I had an email today from our Chile distributor (240volt country) telling me that Torus was unsaleable in his country unless the receptacles were like the ones on the back of the Torus review we sent out today - which are 120 volt USA type. http://www.hometheatersound.com/equipment/torus_power_rm10.htm
It seems to me that the more 'exotic' power cords are of this US style and people want to use these cables with their 240 Volt gear regardless of the safety and liability concerns?

james

[klao]

Hi James,

Almost all after-market AC cables sold in Thailand are with US-style, NEMA 5-15 connectors (15A/125V male plugs and 15A/125V & 10A/250V IECs), despite the local electrical authority's warning of using them with the 220V-240V electricity.

The Shunyata Hydras distributed here are rated at 250V max, with Hubbell made NEMA 5-20R & 20A IEC inlet, however.  The Wattgate 381 on my wall are also specified as 20A/125VAC with NEMA 5-20R type receptacles as well.

I asked an audiophile & equipment dealer here, and he said voltage is not the real problem, exceeding amperage value is.  Another gentleman mentioned that the NEMA 5-15 outlets and plugs are maxed 1,800W at 15A/125V.  When used with 220V current, they should be OK with the equipment not exceeding 8.18A = 1,800W/220V.

Are the statements, formula, and the 1,800W max spec for NEMA 5-15 plug accurate?  I'm not sure about the latter, since the 7B-SST consumes 1,980 Watts / 4 Ohms at peak level and should be able to plug in to one NEMA 5-15 outlet at North American voltage, right?

From the review you posted in other topic: "The RM 10 is rated to continuously provide 10A of current, although it can put out far higher amounts for brief periods: 30A for ten seconds and 80A for one second." ... and 100A peak.  How about the RM 8 INT'L and RM16 INT'L continuous and peak current ratings?  Also, can the INT'L 240V versions be ordered with US-style receptacles?  All my cables can not be used with the back panel outlets as shown in the RM 16 INT'L brochure.

Thank you.

Klao

[James Tanner]

Hi Kloa,

Thank you for this it is very helpful.

Yes in North America the power in most homes is 120 volt 15 amps per circuit. If you wish you can have 20 amp 120 volt circuits but they required different receptacles and plugs – see pictures above.  We also can run 240 volt lines for specialized equipment like stoves, dryers and Air conditioning etc.  A lot of stereo and home theater rooms will have dedicated circuits from the Hydro panel so there is less chance of electrical contamination from other appliances in the house (lots of luck with that!)

In my case for instance, in my main sound room I have a 60 amp 240 volt Torus unit wired directly to the hydro panel and it has 18-- 120 volt outlets on the back for attaching the normal 120 volt gear. This way my equipment is totally ISOLATED and PROTECTED from the outside world.

The maximum output from a 15 amp circuit is 1800 watts as you say and 2400 watts if you use the 20 amp/120 volt setup. What most people do not understand is that most big amplifiers are limited by the current/voltage draw from the wall. So when manufactures tell you that a specific amplifier can put out 3000 watts of power that assumes the wall plug can supply it – a big assumption. That’s why we feel strongly that any power conditioning device should be capable of supplying all the voltage and current swing available from the wall plug.

In the case of the Torus one of the main reasons we got involved was because we realized that the Torus was capable of supplying ‘short term’ current at over 10 times or more the rating of the wall plug.  So when that transient comes along the amp can respond instantaneously to the signal. This is where the output impedance being as low as possible on the Torus is a very important feature. The typical wall plug will have a resistance of 1-2 ohms and will resists transferring that current short term to the amplifier. The Torus can present as low impedance as 0.2 ohms to 0.04 ohms depending on the model. 

Torus has spent many thousands of dollars making sure our products get all the essential Certifications and Safety documentation necessary. All our 240 volt units until recently have used 240 volt IEC style receptacles and we just recently introduced the 240 volt style British and German receptacles as most customers in Europe and the Far East seem to accept these kinds of connectors in 240 volt high end gear.

I think it is an interesting phenomenon that some people will manufacture and sell equipment and other people will use equipment that has no approvals in specific applications. I assume some customers are simply unaware of the risks and some manufactures assume that they will not be held accountable if things go wrong?

James

[klao]

Thanks, James.  Those 240V versions's outlets can be used with so called "Schuko" male plugs, I assume. 

http://www.oyaide.com/e_audio/audio_products_files/e_plug.htm
http://www.furutech.com/2008/product2.asp?prodNo=42

Can you provide photos of their back panels?  Nice to know the type of IEC inlet as well.

Cheers.

[James Tanner]

Thanks, James.  Those 240V versions's outlets can be used with so called "Schuko" male plugs, I assume. 

http://www.oyaide.com/e_audio/audio_products_files/e_plug.htm
http://www.furutech.com/2008/product2.asp?prodNo=42

Can you provide photos of their back panels?  Nice to know the type of IEC inlet as well.

Cheers.

Hi,

I will check with Torus for you and see if we have drawings or pictures yet.

james

[James Tanner]

Hi James,


I asked an audiophile & equipment dealer here, and he said voltage is not the real problem, exceeding amperage value is.  Another gentleman mentioned that the NEMA 5-15 outlets and plugs are maxed 1,800W at 15A/125V.  When used with 220V current, they should be OK with the equipment not exceeding 8.18A = 1,800W/220V.


Thank you.

Klao

Hi Klao,

I checked into this and it is not the case.  The 240V higher voltage on a 120V rated receptacle is cause for concern.

james

[klao]

Hi James,
I asked an audiophile & equipment dealer here, and he said voltage is not the real problem, exceeding amperage value is.  Another gentleman mentioned that the NEMA 5-15 outlets and plugs are maxed 1,800W at 15A/125V.  When used with 220V current, they should be OK with the equipment not exceeding 8.18A = 1,800W/220V.
Thank you.
Klao

Hi Klao,
I checked into this and it is not the case.  The 240V higher voltage on a 120V rated receptacle is cause for concern.
james

Thanks again, James.  It seems I would have to change the plugs on all my power cords to use with Torus Int'l version.  Anyhow, I surveyed the specifications/ratings of some after market AC products (Wattgate, Furutech, & Oyaide), calculated their maximum Watts handling, and translated them into Amps at 240V (max voltage selectable at Torus Int'l version).

US-Style
Receptacles:  20A/125V --> 2,500 Watts; @240V --> 10.42 Amps
15A Plugs:  15A/125V --> 1,875 Watts; @240V --> 7.81 Amps
20A Plugs:  20A/125V --> 2,500 Watts; @240V --> 10.42 Amps

German-style/Schuko
Receptacles: 16A/250 --> 4,000 Watts; @240V --> 16.67 Amps
Plugs: 16A/250 --> 4,000 Watts; @240V --> 16.67 Amps

IEC Connectors
15A IEC:  15A/125V --> 1,875 Watts; @240V --> 7.81 Amps
15A IEC:  usually also rated 10A/250V --> 2,500 Watts; @240V --> 10.42 Amps
20A IEC:  20A/125V --> 2,500 Watts; @240V --> 10.42 Amps
20A IEC:  usually also rated 16A/250V --> 4,000 Watts; @240V --> 16.67 Amps

Would a US-Style receptacle as rated as above (around 10 Amps) be able to handle Torus Int'l 16A?  What if smaller Torus Int'l unit is used instead?  Would the US-style receptacle and 20A plug (for the power cord connecting the Torus) do the job?  Or should I change it to German/Schuko receptacle in any case to handle peak loads from all the components & the Torus?

[James Tanner]

Hi Klao,

As long as you use a rated 240 volt plug your fine.  No Nema 5-15 or 5-20 USA plug is rated at 240 volts.  The size of the Torus is determinded by the Maximum Amperage needed by the system.

james

[James Tanner]

Hi All,

What about Bryston offering custom certified 240 Volt Power cords?

james

[alexone]

 why not? now that Bryston is already offering interconnects and speaker cables the power cords
 would be the missing link...?!

 alex.

[klao]

Hi James,

Agree, if they are carefully tried, tested, and auditioned by trained ears like yours (& those of other Bryston/Taurus staff) that the cords sound good with your equipments.  I'd rather spend one time on the (reasonably) premium-priced quality cords, plugs, cables, etc. than pay many times switching the after-market ones, looking for that syngergy myself.

Klao   

[smerlas]

Hi All,

What about Bryston offering custom certified 240 Volt Power cords?

james

Good idea, but you will need to know country and amperage in order to terminate the cord correctly.  Not sure what is meant by "certified" power cords, may want to check with your legal counsel, they will propably ask you to remove the term "certified".  If terminated correctly this would address a potential liability issue regarding customers "having" to modify cables.  Based on the Torus ratings it would be relatively simple to offer different gauge cords and the correct plugs for the US based on the Underwriters Laboratory (UL) and National Electrial Code (NEC) requirements.

Also the use of 120v outlets for 240v circuits is of great concern.  If allows for the accidental use of the outlet for devices rated at 120v.  I have seen this done in workshops wired by homeowners and anything plugged in and turned on is instantly burned out, huge fire risk.  In a home setting a lamp, TV, CD player plugged into the 15A, 120v duplex receptacle will fry.

And for further consideration ................ if you have created this situation and then sell home, move, etc., you could end up liable for any damage / injury that results from your miswiring of circuits.  If you are not sure of Code requirements, call an electrician.