Electrical switches - Page 3 - Fiberglass RV


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 12-02-2013, 11:23 AM   #29
Senior Member
 
Name: Steve
Trailer: Scamp 13
California
Posts: 1,416
Quote:
Originally Posted by Robert Johans View Post
Okay, thanks for that.

Back to my question: can I use a switch rated for 24vdc in a 12vdc environment "legally"?

Legally speaking are you going to have a problem with 12 volt switch gear in a system charging anywhere from 12.7 volts to 15 volts? Looks to me like you need 24 volt switches to keep the Legal Beagles off your back should something happen.
__________________

__________________
stevebaz is offline   Reply With Quote
Old 12-02-2013, 11:36 AM   #30
Senior Member
 
Byron Kinnaman's Avatar
 
Name: Byron
Trailer: 2006 Scamp 13' towed with a 2005 Dodge Dakota 4.7l Magnum W/full tow package (over kill)
Oregon
Posts: 6,306
Registry
Quote:
Originally Posted by David Tilston View Post

But, there is a current and voltage rating for a reason.
I explained that already.

I'm not sure where the "oil' you're referring to is located, around relay coils (contactor)? Surely not around the contacts.

Capacitors across the contacts are sometimes used to reduce arcing.
__________________

__________________
Byron & Anne enjoying the everyday Saturday thing.
Byron Kinnaman is offline   Reply With Quote
Old 12-02-2013, 11:48 AM   #31
Senior Member
 
Byron Kinnaman's Avatar
 
Name: Byron
Trailer: 2006 Scamp 13' towed with a 2005 Dodge Dakota 4.7l Magnum W/full tow package (over kill)
Oregon
Posts: 6,306
Registry
Changes in current ratings vs voltage ratings.

Automotive and heavy equipment switches made by Valeo specification on voltage/current "Electrical performance: From 20 mA to 16 A at 12V. From 20 mA to 8A at 24V."

The reason for the lower current at the higher voltage (24 volts) is these switches are rated for inductive loads. The reason these are listed this way is because they're used in such a manner that they almost always switch some sort of motor or relay. However this has nothing to do with resistive loads. Note the low current specification, the contacts are NOT gold therefore the 20 mA low end rating.
__________________
Byron & Anne enjoying the everyday Saturday thing.
Byron Kinnaman is offline   Reply With Quote
Old 12-02-2013, 11:54 AM   #32
Senior Member
 
Byron Kinnaman's Avatar
 
Name: Byron
Trailer: 2006 Scamp 13' towed with a 2005 Dodge Dakota 4.7l Magnum W/full tow package (over kill)
Oregon
Posts: 6,306
Registry
Oil bath blurb.

Quote:
Originally Posted by Byron Kinnaman View Post
I explained that already.

I'm not sure where the "oil' you're referring to is located, around relay coils (contactor)? Surely not around the contacts.

Capacitors across the contacts are sometimes used to reduce arcing.
If you can believe what's on the internet, this a quote for GEM manufacturing.

Contacts:
The contacts are immersed in oil bath which enables smooth and cool operation thus offering long life. The contacts made up of Electrolytic copper and brass are suited for vigorous duty. Wear and tear of the contacts are less, compared to air break starters, enhancing the life of the starters.
__________________
Byron & Anne enjoying the everyday Saturday thing.
Byron Kinnaman is offline   Reply With Quote
Old 12-02-2013, 12:06 PM   #33
Senior Member
 
Byron Kinnaman's Avatar
 
Name: Byron
Trailer: 2006 Scamp 13' towed with a 2005 Dodge Dakota 4.7l Magnum W/full tow package (over kill)
Oregon
Posts: 6,306
Registry
Back to the OP

Quote:
Originally Posted by Robert Johans View Post
I am less than satisfied with the quality and aesthetics of typical 12VDC switches both those for automotive use as well as RV.

Are there any good looking light switches (and cover plates) available anywhere that will function properly and safely with 12VDC power?

Here are a couple examples of the look I'm going for...
There's lots of options that you could use, look at electronic catalogs for switches and there's tons of them. I add some CCFL lights to my trailer and I'm 3/4" round rocker switches that I got a Radio Shack (shudder). I think you're using LED lighting, if so, almost any switch will work just fine therefore you can use styling as your main concern.
__________________
Byron & Anne enjoying the everyday Saturday thing.
Byron Kinnaman is offline   Reply With Quote
Old 12-02-2013, 12:51 PM   #34
Senior Member
 
David Tilston's Avatar
 
Name: Dave W
Trailer: Trillium 4500 - 1977, 1978 (2), 1300 - 1977, 1973, and a 1972
Alberta
Posts: 5,314
Registry
Quote:
Originally Posted by Byron Kinnaman View Post
If you can believe what's on the internet, this a quote for GEM manufacturing.

Contacts:
The contacts are immersed in oil bath which enables smooth and cool operation thus offering long life. The contacts made up of Electrolytic copper and brass are suited for vigorous duty. Wear and tear of the contacts are less, compared to air break starters, enhancing the life of the starters.
This is not really the place for a discussion on utility breakers, but bulk oil, min oil and SF6 breakers are about breaking the arc. And Yes, the contacts are immersed in oil. The SF6 breakers don't use oil.

The only point I am trying to make is that current carrying capacity is not the only design consideration. Interrupting capacity is also important. This is why the DC rating is different from the AC rating for a switch.

From the specs of a pressure switch that my company sells:
11 amps, 1/4 hp at 125, 250 VAC; 5 amps resistive, 3 amps inductive 28 VDC;
.5 amps resistive at 28 VDC

Note that 11 amps at 250 VAC becomes 0.5 amps resistive at 28 VDC
__________________
David Tilston is offline   Reply With Quote
Old 12-02-2013, 12:54 PM   #35
Senior Member
 
Byron Kinnaman's Avatar
 
Name: Byron
Trailer: 2006 Scamp 13' towed with a 2005 Dodge Dakota 4.7l Magnum W/full tow package (over kill)
Oregon
Posts: 6,306
Registry
Quote:
Originally Posted by david tilston View Post
this is not really the place for a discussion on utility breakers, but bulk oil, min oil and sf6 breakers are about breaking the arc. And yes, the contacts are immersed in oil. The sf6 breakers don't use oil.

The only point i am trying to make is that current carrying capacity is not the only design consideration. Interrupting capacity is also important. This is why the dc rating is different from the ac rating for a switch.

From the specs of a pressure switch that my company sells:
11 amps, 1/4 hp at 125, 250 vac; 5 amps resistive, 3 amps inductive 28 vdc;
.5 amps resistive at 28 vdc

note that 5 amps resistive at 250 vac becomes 0.5 amps resistive at 28 vdc

just plan wrong...


Automotive and heavy equipment switches made by Valeo specification on voltage/current "Electrical performance: From 20 mA to 16 A at 12V. From 20 mA to 8A at 24V."
__________________
Byron & Anne enjoying the everyday Saturday thing.
Byron Kinnaman is offline   Reply With Quote
Old 12-02-2013, 01:15 PM   #36
Commercial Member
 
Robert Johans's Avatar
 
Name: Robert
Trailer: Nest Caravans
Oregon
Posts: 822
Registry
Gentlemen, gentlemen!

Can we agree that, within our 12VDC travel trailer environment, a DC-rated, 24VDC switch is perfectly acceptable to control a bank of LED light fixtures drawing no more than 15 watts?
__________________
Robert Johans is offline   Reply With Quote
Old 12-02-2013, 01:50 PM   #37
Senior Member
 
David Tilston's Avatar
 
Name: Dave W
Trailer: Trillium 4500 - 1977, 1978 (2), 1300 - 1977, 1973, and a 1972
Alberta
Posts: 5,314
Registry
Quote:
Originally Posted by Byron Kinnaman View Post
just plan wrong...


Automotive and heavy equipment switches made by Valeo specification on voltage/current "Electrical performance: From 20 mA to 16 A at 12V. From 20 mA to 8A at 24V."
Byron,

What you have posted is just a comparison of two DC current ratings, lower at a higher voltage. Common sense. But the discussion is about AC ratings vs. DC ratings. If a switch is rated at 20 amps AC, it may have a much lower DC rating.

The specs that I posted are not "just plan wrong". They are determined by the manufacture through testing and research. Why do you say they are wrong?
__________________
David Tilston is offline   Reply With Quote
Old 12-02-2013, 01:52 PM   #38
Senior Member
 
David Tilston's Avatar
 
Name: Dave W
Trailer: Trillium 4500 - 1977, 1978 (2), 1300 - 1977, 1973, and a 1972
Alberta
Posts: 5,314
Registry
Quote:
Originally Posted by Robert Johans View Post
Gentlemen, gentlemen!

Can we agree that, within our 12VDC travel trailer environment, a DC-rated, 24VDC switch is perfectly acceptable to control a bank of LED light fixtures drawing no more than 15 watts?
I would be comfortable saying that a 28VDC switch should be fine at 12VDC with the same current rating. At 15 watts, the current should not be much over 1 amp.
__________________
David Tilston is offline   Reply With Quote
Old 12-02-2013, 02:20 PM   #39
Senior Member
 
Name: None
Trailer: None
None
Posts: 2,727
Ul

UL is a recognized testing and certifying lab. I installed a sign for a store in the Mall Of America. The sign came out of the south and did not have a UL sticker . I pointed this out to the store owner and the Mall of America . The store owner said install the sign over the objections of the Mall of America
The electrical inspector asked "Where is the UL sticker" and I explained the situation .Well we took the sign back out ,shipped it back to the manufacturer for reinspection and application of a UL sticker per UL standards
Electrical equipment is required to be certified by a recognized testing authority and the local enforcing authority (inspector) has the power to interpret the NEC . NO you can NOT just ship up a sticker and stick it on the equipment on site and be in UL compliance. This issue is a constant problem with pieces of equipment built overseas . I had a $6 000,000 German printing press sitting idle for 6 months waiting for UL certification Some parts of the country enforce the NEC others do not
__________________
steve dunham is offline   Reply With Quote
Old 12-02-2013, 02:53 PM   #40
Senior Member
 
Joe MacDonald's Avatar
 
Trailer: Trillium
Ontario
Posts: 753
oooh oooh oooh..........sulfur-hexaflouride, I never thought I'd see that in a fiberglass trailer discussion!!!
I don't think you could fit that switch in a camper.

Here is a well thought out article that should clear up what is trying to be said: www.eaa.org/sportaviationmag/2005/0502_switches.pdf‎

I am an electrician, and I do wire in DC frequently. Read the rating, respect the rating, and use the right piece of kit. You might get away with something else, or you might not.

just my 2 cents
__________________
Joe MacDonald is offline   Reply With Quote
Old 12-02-2013, 03:03 PM   #41
Commercial Member
 
Robert Johans's Avatar
 
Name: Robert
Trailer: Nest Caravans
Oregon
Posts: 822
Registry
Quote:
Originally Posted by David Tilston View Post
I would be comfortable saying that a 28VDC switch should be fine at 12VDC with the same current rating. At 15 watts, the current should not be much over 1 amp.
I don't know if it makes much difference, but I am defining the switch as 24VDC, not 28VDC.

Nevertheless, the DC-rated switches I have found are rated at 3amps.

Just want to ensure that my switches pass inspection...
__________________
Robert Johans is offline   Reply With Quote
Old 12-02-2013, 03:23 PM   #42
Senior Member
 
Ice-breaker's Avatar
 
Name: Dave W
Trailer: Escape 19 and Escape 15B
Alberta
Posts: 470
Robert, you could use a 12V DC switch similar to these:




Escape uses switches very similar to these in their trailers. I saw the above pics on the Yahoo shopping site and similar pics (with other colors) on EBay, so I am sure you can find them if you are interested:
__________________

__________________
Dave W - 2013 Escape 19', 2013 Escape 15B and 2011 Toyota FJ Cruiser

"You've got to be very careful if you don't know where you are going, because you might not get there." - Yogi Berra
Ice-breaker is offline   Reply With Quote
Reply

Tags
electrical


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Electrical help! BarbieB Electrical | Charging, Systems, Solar and Generators 8 11-18-2013 07:18 PM
All new electrical system kyle minor Modifications, Alterations and Updates 4 06-04-2010 12:02 PM
Can Low Voltage Fry the Breaker Switches? Adrian W Problem Solving | Owners Helping Owners 4 07-22-2008 12:55 PM
Electrical bdiscount Electrical | Charging, Systems, Solar and Generators 6 06-27-2006 09:21 PM
13 Scamp 120V, 12V, Propane Switches LeBoutillier Problem Solving | Owners Helping Owners 8 03-18-2006 05:39 PM

» Upcoming Events
No events scheduled in
the next 465 days.
» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 10:09 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.