120v relay mounting with 12v input

[electron]

Really cool relay, but man, that's pricey  Is that as cheap as they get, or did you just randomly link one?

 

[BraveSirRobbin]

Relays are so 2012.
 
You might want to look at these:
http://www.opto22.com/site/pr_details.aspx?cid=3&item=120A10
 
No moving parts, 4000V isolation between input and output, work in all conditions, no coil voltage spike.  I use them all the time and they work great.

They are good for AC load switching, but if switching DC analog loads I would not recommend them as they do have a voltage drop across the output.  Also, I believe in the past I had trouble using SSR's with highly inductive loads.  I also had a work app many years ago that required a lot of repetitive switching and they continually failed, where a mechanical worked just fine (go figure).
 
Again, a great product and it works well, but does have some limitations IMO to be aware of.

 

[ano]

Check eBay for cheaper prices.  Just watch out for real cheap ones from China.  Look for UL listing, but make sure its not counterfeit. 
 
They do have a voltage drop while turned on of about a volt or two, which means they could dissipate some power for high current loads.  I used to use one of these to control an electric hot water heater, and even there, if you mount it to a piece of metal to dissipate the heat, its fine.   If your controlling just a light bulb, its not a big deal.

 

[sda]

Dug up this thread, some of you guys have me a little worried now trying to use a M1XOVR as a relay board for some AC switching.
 
What I wanted to do was use the board to provide lighting control for 6 bedroom/hall closets via outputs from the M1.
 
Was going to centrally mount in a UB12 and in one corner of the same UB box place a 4x4 junction box for most of HV wiring except the conductors feeding to the board of course.  The only LV wires would be the databus cable.  I only need 6 relays so figure the #7 and #8 relay spot which is next to the databus would be empty so can provide decent clearance between the LV / HV wiring.
 
Too risky?

You aren't going to be able to put all those cables/wires into a 4x4.
 
There's probably more to consider on the HV side of things ...
new lights, existing lights, new circuit, one old circuit, two or more existing circuits, retain manual switches.

 

[apostolakisl]

Relays are so 2012.
 
You might want to look at these:
http://www.opto22.com/site/pr_details.aspx?cid=3&item=120A10
 
No moving parts, 4000V isolation between input and output, work in all conditions, no coil voltage spike.  I use them all the time and they work great.

 
I have one of those that I got off of ebay from China.  It has all the right markings on it, but who knows it could be counterfeit.  I am using it to power a garbage disposal on an island.  I didn't want to drill a hole and put one of those air switches (I dislike penetrating countertops any more than is absolutely necessary because it just gets grimy at the crease).  I used that relay, a 9v batter, and a small toggle switch that I mounted under the lip of the counter to control the garbage disposal.  It works very nicely.  The switch is easily accessible, protected from accidental bumping by being tucked under the lip of the counter, and unless you are less than 36 inches tall, pretty much totally invisible.
 
They are not perfect switches, however.  As mentioned they have resistance resulting in some drop in voltage, which produces heat at higher current loads/long duration of being on, and when off, they still have a very small leak of current.  But for a garbage disposal, they are perfect.  Since it is only on for a few seconds here and there, the 9v battery has lasted 4 years and probably will last another 4 (or more).

 

[archstenton]

You aren't going to be able to put all those cables/wires into a 4x4.
 
There's probably more to consider on the HV side of things ...
new lights, existing lights, new circuit, one old circuit, two or more existing circuits, retain manual switches.

 
You're probably right, I forgot about the wires back and forth to the M1XOVR. doh!
 
Don't have one handy, but what maybe 20 14 wires in a 4x4 box?
 
With 6 relays, that's 12 wires.
 
Incoming unswitched/neutral/ground into box is 3 more.
 
Switched/neutral to the 6 lights, that's 12 more.
 
So 12+3+12=27 probably too many not to mention will have an unusual amount of wire nuts adding to the congestion.  So at least a pair of 4x4's?  Looking it up now, a 14 is 2 cu, inches, so yeah would need around 54 cu. in. minimum, so probably a pair of 4x4's or try to fanagle a 3-4 gang outlet box.

 

[sda]

A 4x4 deep (2-1/8') is a bit over 30ci.
Two boxes will still be crowded with half the wires.
 
A 14" enclosure with 3 4 squares inside it.
Two switch circuits to a box.
 
Mount the boxes on the right side (or side with the least prepunched stuff) of the enclosure.
Punch out the box knockouts you'll use and use a knockout punch go through the side of the enclosure.
Bring your feed into the center box and split it.
 
Check ebay for "ELK SWB14" - there's a seller that has them for $10 plus shipping.
(I bought two the other day but they haven't shown up yet)