Forum Jump: 
 49Likes
Reply
 
Thread Tools
post #31 of 488 Old 01-05-2011, 01:04 PM
AVS Forum Addicted Member
 
noah katz's Avatar
 
Join Date: Apr 1999
Location: Mountain View, CA USA
Posts: 22,192
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1529 Post(s)
Liked: 535
Very nice, and thanks for reminding me that my 4311 has 12V triggers.

I don't care for the solid state relays because they dissipate power; note that yours are rated for only 5 A w/o heat sinks.

Mechanical relays have been used for decades to switch heavy inductive loads and work just fine.

Noah
noah katz is offline  
Sponsored Links
Advertisement
 
post #32 of 488 Old 01-05-2011, 01:06 PM
AVS Forum Special Member
 
Warpdrv's Avatar
 
Join Date: Oct 2005
Location: Wisconsin
Posts: 7,313
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 17
Quote:
Originally Posted by J_Palmer_Cass View Post
I think that setup is a NEC code violation. You are required to have a barrier between low voltage and line voltage wiring to conform.
What constitutes as a barrier...?


Quote:
Originally Posted by A9X-308 View Post
Are devices plugged into the wall outlet, ie not permanently directly wired to the mains covered by the NEC?

If using a mechanical relay, use a flyback diode on the coil especially if being driven from an AVR etc 12V trigger. See snubber link earlier.
My 12v comes from a wall wart that is plugged into a Smart Strip, that senses when my plasma turns on.... The only thing I 12v trigger from my Pre-Amp is my amp for my speakers....
Warpdrv is offline  
post #33 of 488 Old 01-05-2011, 01:20 PM - Thread Starter
AVS Forum Special Member
 
notnyt's Avatar
 
Join Date: Dec 2008
Location: Long Island, NY
Posts: 9,802
Mentioned: 290 Post(s)
Tagged: 0 Thread(s)
Quoted: 3461 Post(s)
Liked: 3422
Quote:
Originally Posted by noah katz View Post
Very nice, and thanks for reminding me that my 4311 has 12V triggers.

I don't care for the solid state relays because they dissipate power; note that yours are rated for only 5 A w/o heat sinks.

Mechanical relays have been used for decades to switch heavy inductive loads and work just fine.
That big metal box its mounted to.. I reckon it will work as a heat sink just fine.

If not, it will take all of 10 minutes to switch to a mechanical relay?
notnyt is offline  
Sponsored Links
Advertisement
 
post #34 of 488 Old 01-05-2011, 01:24 PM
AVS Forum Addicted Member
 
noah katz's Avatar
 
Join Date: Apr 1999
Location: Mountain View, CA USA
Posts: 22,192
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1529 Post(s)
Liked: 535
I doubt you have an issue, as the average current consumption will be low.

I just try to avoid adding to the nickle-and-diming of power consumption.

Noah
noah katz is offline  
post #35 of 488 Old 01-05-2011, 07:06 PM
AVS Forum Addicted Member
 
Stereodude's Avatar
 
Join Date: Jan 2002
Location: Detroit Metro Area
Posts: 14,885
Mentioned: 32 Post(s)
Tagged: 0 Thread(s)
Quoted: 3959 Post(s)
Liked: 2839
Ahh yes, the ol' NEC / code argument. The NEC allows mixing low voltage and high voltage in an enclosure under some circumstances.

Otherwise the argument is effectively that it's a code violation to use a relay since you'll always have low and high voltage together, which is absurd since they're used all the time in enclosures.
Stereodude is offline  
post #36 of 488 Old 01-05-2011, 07:12 PM
AVS Forum Addicted Member
 
Stereodude's Avatar
 
Join Date: Jan 2002
Location: Detroit Metro Area
Posts: 14,885
Mentioned: 32 Post(s)
Tagged: 0 Thread(s)
Quoted: 3959 Post(s)
Liked: 2839
I'm also not sure you need the snubber unless you plan to turn the relay off while the amp is consuming high levels of current. It seems unlikely that you'll turn it off while the volume cranked and you're playing loud bass. If you've got any sort of delay in the loop the sub amp will turn off while it is silent.

You also aren't dealing with a very inductive load.

The snubber might be most useful across the trigger's coil to prevent any potential damage if you were using your receiver's trigger output. However, if you're using a power supply it's probably not that important.
Stereodude is offline  
post #37 of 488 Old 01-05-2011, 07:37 PM
AVS Forum Special Member
 
A9X-308's Avatar
 
Join Date: Mar 2008
Location: Australia
Posts: 8,143
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 1670 Post(s)
Liked: 1337
Quote:
Originally Posted by Warpdrv View Post

What constitutes as a barrier...?

I would have thought the term would have been defined in the legislation and documentation related to the subject. I know such terms are here and are the entire first section of AS3000.

Quote:
Originally Posted by Warpdrv View Post

My 12v comes from a wall wart that is plugged into a Smart Strip, that senses when my plasma turns on.... The only thing I 12v trigger from my Pre-Amp is my amp for my speakers....

I was curious as my question I thought made clear. This remote control of an appliance via a relay is a device that is pluggable and can be removed, so I wondered whether the rules covered it there or not.

“You are not special. You are not a beautiful and unique snowflake.” Chuck Palahniuk
A9X-308 is online now  
post #38 of 488 Old 01-05-2011, 07:43 PM
Advanced Member
 
two-rocks's Avatar
 
Join Date: Dec 2001
Location: Cape Cod
Posts: 548
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
I've been switching 2 20A circuits using mechanical relays (40A rated)- except I used the ac/ac type and fired them from the switched outlet in the back of the AVR....I knew about the dc separation and didn't know how to solve it....

New Avr's don't seem to have these outlets and I needed to do something quick to make it work when I upgraded avr's so I grabbed a device from sears that activates the outlet when main power is called for (similar to eco power strips). Relay activating a relay...

On another note, I;m not sure what amps people use, but my pro amps power on and within a second add the full current (as the fans slow down and the lights go from all on to normal) so no fear of large inrush at startup.

Or maybe change to some coils like these:
http://www.electronicsurplus.com/Ite...AZ2100-1A-9DE/
two-rocks is offline  
post #39 of 488 Old 01-05-2011, 09:19 PM
AVS Forum Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,604
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 394 Post(s)
Liked: 118
Quote:
Originally Posted by Warpdrv View Post

What constitutes as a barrier...?


First example:

http://www.smarthome.com/2546/Low-Vo...e-SCDIV/p.aspx


Second example:

http://www.hubbellcatalog.com/raco/R...&FAM=RacoBoxes
J_Palmer_Cass is offline  
post #40 of 488 Old 01-05-2011, 09:56 PM
AVS Forum Special Member
 
Servicetech571's Avatar
 
Join Date: Apr 2008
Posts: 4,696
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 13
If you are looking for a local/low cost source for a heavy duty relay there are 2 options:

1: HVAC A/C contactor, these are designed to control a central A/C unit. No 120V load will ever create a "contact weld" issue, the contacts are HUGE on these bad boys. Cost about $20 at local HVAC supply. Rated @ 24VAC for the coil but most work fine with a 12VDC trigger. No need to use 1/4" terminals for A/C line, contractor comes with screw clamps. 1/4" spades used for coil terminals. Example: http://www.midwesthvacparts.com/Prod...rs-90-246.aspx

2: Automotive starter relay can handle 100A for a car starter, costs about the same as the HVAC relay. Can purchase from most car parts stores.
Example: http://www.autopartswarehouse.com/de...e&apwidNnQMe95
Servicetech571 is offline  
post #41 of 488 Old 01-05-2011, 11:28 PM
AVS Forum Special Member
 
A9X-308's Avatar
 
Join Date: Mar 2008
Location: Australia
Posts: 8,143
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 1670 Post(s)
Liked: 1337
Most automotive relays are not rated to switch 120Vac.

“You are not special. You are not a beautiful and unique snowflake.” Chuck Palahniuk
A9X-308 is online now  
post #42 of 488 Old 01-06-2011, 06:36 AM - Thread Starter
AVS Forum Special Member
 
notnyt's Avatar
 
Join Date: Dec 2008
Location: Long Island, NY
Posts: 9,802
Mentioned: 290 Post(s)
Tagged: 0 Thread(s)
Quoted: 3461 Post(s)
Liked: 3422
Quote:

If you really want to stick to the code, doesn't it say the barrier must be non conductive? How much sense does that even make in a metal box though =]
notnyt is offline  
post #43 of 488 Old 01-06-2011, 07:03 AM
AVS Forum Special Member
 
Servicetech571's Avatar
 
Join Date: Apr 2008
Posts: 4,696
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Liked: 13
Quote:
Originally Posted by A9X-308 View Post

Most automotive relays are not rated to switch 120Vac.

Contacts are contacts. The amperage just goes down as the voltage goes up. Th HVAC contactor is still my fav since it can switch 2 sources or both sides of the line at the same time.
Servicetech571 is offline  
post #44 of 488 Old 01-06-2011, 10:27 AM
AVS Forum Special Member
 
A9X-308's Avatar
 
Join Date: Mar 2008
Location: Australia
Posts: 8,143
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 1670 Post(s)
Liked: 1337
Quote:
Originally Posted by Servicetech571 View Post

Contacts are contacts.

No they are not. Do not use devices that are not rated for the application. It is dangerous and stupid.

“You are not special. You are not a beautiful and unique snowflake.” Chuck Palahniuk
A9X-308 is online now  
post #45 of 488 Old 01-06-2011, 10:40 AM - Thread Starter
AVS Forum Special Member
 
notnyt's Avatar
 
Join Date: Dec 2008
Location: Long Island, NY
Posts: 9,802
Mentioned: 290 Post(s)
Tagged: 0 Thread(s)
Quoted: 3461 Post(s)
Liked: 3422
Seeing what happens to automotive relays is one of the reasons I went with solid state relays =]
notnyt is offline  
post #46 of 488 Old 01-06-2011, 10:59 AM
AVS Forum Special Member
 
A9X-308's Avatar
 
Join Date: Mar 2008
Location: Australia
Posts: 8,143
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 1670 Post(s)
Liked: 1337
The advantage of SSR's over EMR's in this application is zero cross switching with no additional circuitry required.

“You are not special. You are not a beautiful and unique snowflake.” Chuck Palahniuk
A9X-308 is online now  
post #47 of 488 Old 01-06-2011, 02:32 PM
AVS Forum Special Member
 
petew's Avatar
 
Join Date: Oct 2000
Location: Albuquerque, NM USA
Posts: 2,119
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 69
Zero cross switching - good factoid to know.

I've considered building a relay box to switch my three Rotel amps (RB-991 time two and one RB-993). Problem is, when I switch them on manually with a power strip they pop the 20A breaker about 30% of the time. My house has those stupid fast blow breakers that the gubment requires now.

I wonder if zero crossing will help there by lessening inrush current? Otherwise I'd have to rig some kind of delay and use three SSR's. Maybe I can find an old stock slow blow breaker somewhere, right next to the incandescent light bulbs and cans of R-12.

High Desert Theater - work in progress
Building Bass - Subs
Surrounds - Easy as Pi
Storage - unRAID unDELL
Mains - Another piece of Pi
petew is offline  
post #48 of 488 Old 01-06-2011, 02:51 PM
AVS Forum Special Member
 
A9X-308's Avatar
 
Join Date: Mar 2008
Location: Australia
Posts: 8,143
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 1670 Post(s)
Liked: 1337
Inrush is due to the PS caps being discharged at turn on. Zero cross switching will reduce it to some extent, but they will still need to charge and that basically depends upon the cap size and PS impedance upstream of them.

I have 14 amps to switch, so mine are designed to come in one at a time. If you are having issues with the total inrush causing the breakers to trip, you might need to make a couple of these units and turn them on one at a time manually. I have a system controller (my own design custom unit) that does this for me automatically.

I am surprised that breakers are tripping though. Are there other devices that draw a lot of current on the same mains spur? Typical breaker I/t characteristics will allow for 7-10x rated for a second or two which should be more than enough for a couple of poweramps.
LL

“You are not special. You are not a beautiful and unique snowflake.” Chuck Palahniuk
A9X-308 is online now  
post #49 of 488 Old 01-06-2011, 03:50 PM
AVS Forum Special Member
 
petew's Avatar
 
Join Date: Oct 2000
Location: Albuquerque, NM USA
Posts: 2,119
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 69
Quote:
Originally Posted by A9X-308 View Post


I am surprised that breakers are tripping though.

My electrician tells me it's just the nature of the new breakers required in USA. I have another 15A circuit with a 600 watt magnetic transformer for low voltage lighting. If I use the internal photocell to switch the lights on it pops the breaker too. We swapped out that breaker with no success. Had to go to a relay on the 12v side to control the lights and leave the transformer hot.

And don't get me started on arc fault interrupt breakers.

High Desert Theater - work in progress
Building Bass - Subs
Surrounds - Easy as Pi
Storage - unRAID unDELL
Mains - Another piece of Pi
petew is offline  
post #50 of 488 Old 01-06-2011, 04:39 PM - Thread Starter
AVS Forum Special Member
 
notnyt's Avatar
 
Join Date: Dec 2008
Location: Long Island, NY
Posts: 9,802
Mentioned: 290 Post(s)
Tagged: 0 Thread(s)
Quoted: 3461 Post(s)
Liked: 3422
Quote:
Originally Posted by petew View Post


And don't get me started on arc fault interrupt breakers.

Hah. I hate those things.
notnyt is offline  
post #51 of 488 Old 01-06-2011, 05:51 PM
AVS Forum Addicted Member
 
noah katz's Avatar
 
Join Date: Apr 1999
Location: Mountain View, CA USA
Posts: 22,192
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1529 Post(s)
Liked: 535
Quote:
Originally Posted by A9X-308 View Post

Inrush is due to the PS caps being discharged at turn on.

I think you mean charged

Noah
noah katz is offline  
post #52 of 488 Old 01-06-2011, 07:14 PM
AVS Forum Special Member
 
A9X-308's Avatar
 
Join Date: Mar 2008
Location: Australia
Posts: 8,143
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 1670 Post(s)
Liked: 1337
Quote:
Originally Posted by noah katz View Post

I think you mean charged

No, they start out discharged and there is an inrush to fill them.

“You are not special. You are not a beautiful and unique snowflake.” Chuck Palahniuk
A9X-308 is online now  
post #53 of 488 Old 01-06-2011, 07:51 PM
Senior Member
 
reverse's Avatar
 
Join Date: May 2005
Location: Austin, TX
Posts: 324
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Liked: 12
This is what DIY is all about:





Adhering to codes just makes things more difficult
binarysoldier likes this.
reverse is offline  
post #54 of 488 Old 01-07-2011, 12:23 AM
AVS Forum Addicted Member
 
noah katz's Avatar
 
Join Date: Apr 1999
Location: Mountain View, CA USA
Posts: 22,192
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1529 Post(s)
Liked: 535
Quote:
Originally Posted by A9X-308 View Post

No, they start out discharged and there is an inrush to fill them.

Ergo inrush is due to the PS caps being *charged* at turn on.

Noah
noah katz is offline  
post #55 of 488 Old 01-07-2011, 02:55 AM
AVS Forum Special Member
 
Peter M's Avatar
 
Join Date: Sep 2000
Location: Sydney
Posts: 1,913
Mentioned: 11 Post(s)
Tagged: 1 Thread(s)
Quoted: 302 Post(s)
Liked: 270
I've posted this a few times before, usually to an underwhelming response, but anyway here it is again ... from the depths of the AVS archives ...

http://archive.01966633.com/avs-vb/s...hreadid=448079

In summary, it's an IR remote controlled 12 channel relay board, which can be turned into something very useful by the average DIYer.

Hopefully someone may find it useful. AFAIK the board is still available.
Peter M is offline  
post #56 of 488 Old 01-07-2011, 08:07 AM
AVS Forum Special Member
 
petew's Avatar
 
Join Date: Oct 2000
Location: Albuquerque, NM USA
Posts: 2,119
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 29 Post(s)
Liked: 69
Lots of cool gizmos on that site, Peter. Bookmarked.
Thanks.

High Desert Theater - work in progress
Building Bass - Subs
Surrounds - Easy as Pi
Storage - unRAID unDELL
Mains - Another piece of Pi
petew is offline  
post #57 of 488 Old 01-07-2011, 12:26 PM
AVS Forum Special Member
 
Warpdrv's Avatar
 
Join Date: Oct 2005
Location: Wisconsin
Posts: 7,313
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 17
Quote:
Originally Posted by Peter M View Post
I've posted this a few times before, usually to an underwhelming response, but anyway here it is again ... from the depths of the AVS archives ...

http://archive.01966633.com/avs-vb/s...hreadid=448079

In summary, it's an IR remote controlled 12 channel relay board, which can be turned into something very useful by the average DIYer.

Hopefully someone may find it useful. AFAIK the board is still available.
Cool.... nice, and thanks for that useful thread link...
http://www.kitsrus.com/kits3.html
Kit # 142
Warpdrv is offline  
post #58 of 488 Old 01-07-2011, 08:49 PM
AVS Forum Special Member
 
Peter M's Avatar
 
Join Date: Sep 2000
Location: Sydney
Posts: 1,913
Mentioned: 11 Post(s)
Tagged: 1 Thread(s)
Quoted: 302 Post(s)
Liked: 270
You're very welcome guys. Amazing that the board is still available. I've been using mine regularly for about 6 years and I thinks it's brilliant !
Peter M is offline  
post #59 of 488 Old 05-03-2011, 05:23 PM - Thread Starter
AVS Forum Special Member
 
notnyt's Avatar
 
Join Date: Dec 2008
Location: Long Island, NY
Posts: 9,802
Mentioned: 290 Post(s)
Tagged: 0 Thread(s)
Quoted: 3461 Post(s)
Liked: 3422
Just ordered 4x Omron G7L-1A-TUB-J-CB-DC12 30A relays. Upgrading to bigger amps
notnyt is offline  
post #60 of 488 Old 05-03-2011, 05:52 PM
AVS Forum Addicted Member
 
LTD02's Avatar
 
Join Date: Oct 2003
Posts: 21,094
Mentioned: 766 Post(s)
Tagged: 1 Thread(s)
Quoted: 2866 Post(s)
Liked: 3521
"Upgrading to bigger amps"

so, you have decided to do it?

what gauge wire are you running from your service panel to your receptacles? you are looking at 220v w/30 amps, right?

Listen. It's All Good.
LTD02 is offline  
Sponsored Links
Advertisement
 
Reply DIY Speakers and Subs



Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off