Can an ELK-P412(K) be moved into a std. can?

Sacedog

Active Member
I need a lot of power for powered sensors (glass break, smokes, COs, etc.), and am thinking I need to go with the ELK-P412(K). Is is OK to remove the internal componants of the can that it comes in, and install them in a standard structured wiring can?

I would rather not have to mount the ELK-P412(K) on the wall, as all of my other cans will be flush mounted. Plus, wall space will be at a premium in the closet.

Is this not advisable? Would the inspector (new home build) have a fit?
 
FWIW, I'm also considering disassembling the P412K unit and remounting its components within a larger, structured wiring can. I have the same concerns about mixing a "naked" high-voltage power supply within an otherwise low-voltage environment.

I suspect all 120VAC connections must be isolated (i.e. within an approved enclosure) from low-voltage connections. As a result, I'm leaning towards simply installing the entire P412K unit within the structured wiring can. One could argue that this "box within a box" idea would lead to overheating. I'm guessing that this is not a legitimate concern because the P412K's case wasn't designed with any cooling vents so it probably doesn't generate excessive amounts of heat.

Can someone confirm that the P412K can be safely mounted within a wiring can?
 
FWIW, I'm also considering disassembling the P412K unit and remounting its components within a larger, structured wiring can. I have the same concerns about mixing a "naked" high-voltage power supply within an otherwise low-voltage environment.

I suspect all 120VAC connections must be isolated (i.e. within an approved enclosure) from low-voltage connections. As a result, I'm leaning towards simply installing the entire P412K unit within the structured wiring can. One could argue that this "box within a box" idea would lead to overheating. I'm guessing that this is not a legitimate concern because the P412K's case wasn't designed with any cooling vents so it probably doesn't generate excessive amounts of heat.

Can someone confirm that the P412K can be safely mounted within a wiring can?

Thats what I did. Mounted it in a 14" can, which is just large enough for the power supply and two batteries. Check out the link in my sig for pictures. The only issue I have is that the keylock scapes against one of the batteries. If I had to do it over again, I would mount the batteries on the opposite side of the keylock.

It's not a really a "naked" power supply, it's enclosed. The screw terminals for the high voltage have covers the rest is all low voltage.
 
Nice wuench! That is exactally what I was thinking of doing. I guess I need to order one more can. :ph34r:

Hopefully, Spanky will chime in to verify that this is an OK thing to do. Like you said, the power supply is enclosed, so it seems like it would not be a hazzard.
 
Congratulations! That's an impressive project ... and beautifully documented!


FWIW, our in-house project engineer (our company provides commercial alarm and video security systems) indicated that one should not mix high and low-voltage devices within the same wiring can. If you must, then all 120VAC connections ought to be enclosed (i.e. box within a box).

I believe the rationale is to mitigate the risk of serious injury. By segregating high and low voltage components, you lower the risk of electrocution when you open the wiring can to do something mundane (like connect the wire for a new zone).

If you open an alarm panel's wiring can, you expect to find low-voltage (12VDC) connections, exclusively. You don't expect to find uninsulated 120VAC connections ... like on the terminal strip of the P412's regulator.

wuench's approach still exposes you to the risk of electrocution even if you need to do something mundane ... unplug the wall-wart and you could brush against the regulator's terminal strip. Cover the terminal strip and you minimize that risk.
 
Congratulations! That's an impressive project ... and beautifully documented!


FWIW, our in-house project engineer (our company provides commercial alarm and video security systems) indicated that one should not mix high and low-voltage devices within the same wiring can. If you must, then all 120VAC connections ought to be enclosed (i.e. box within a box).

I believe the rationale is to mitigate the risk of serious injury. By segregating high and low voltage components, you lower the risk of electrocution when you open the wiring can to do something mundane (like connect the wire for a new zone).

If you open an alarm panel's wiring can, you expect to find low-voltage (12VDC) connections, exclusively. You don't expect to find uninsulated 120VAC connections ... like on the terminal strip of the P412's regulator.

wuench's approach still exposes you to the risk of electrocution even if you need to do something mundane ... unplug the wall-wart and you could brush against the regulator's terminal strip. Cover the terminal strip and you minimize that risk.

While I understand what you are saying, I fail to see the difference between this and the Elk can the 412k comes in. It is just a smaller can with high and low voltage mixed. I just used a bigger can and put two batteries in it. The high voltage terminals have snap on covers on them, so there are no exposed connections. I think this makes the enclosed power supply and covered terminals basically the same as a can within a can. Also I should mention, the outlets in the can are plugged into another outlet, giving me a way to completely disconnect the can to service it.

But certainly consider all of this before duplicating what I have done, safety first. I am sure there is always a better way...
 
Congratulations! That's an impressive project ... and beautifully documented!


FWIW, our in-house project engineer (our company provides commercial alarm and video security systems) indicated that one should not mix high and low-voltage devices within the same wiring can. If you must, then all 120VAC connections ought to be enclosed (i.e. box within a box).

I believe the rationale is to mitigate the risk of serious injury. By segregating high and low voltage components, you lower the risk of electrocution when you open the wiring can to do something mundane (like connect the wire for a new zone).

If you open an alarm panel's wiring can, you expect to find low-voltage (12VDC) connections, exclusively. You don't expect to find uninsulated 120VAC connections ... like on the terminal strip of the P412's regulator.

wuench's approach still exposes you to the risk of electrocution even if you need to do something mundane ... unplug the wall-wart and you could brush against the regulator's terminal strip. Cover the terminal strip and you minimize that risk.


I think your in-house engineer is actually following the NEC requirements for seperation of circuits. Power Limited circuits shall be reliably maintained a minimum of .25 inches from non power limited (in this case mains supply and battery leads etc).

Also the NEC and UL have requirements for protection of service persons etc.

Always good to follow the NEC for safety and those pesky electrical inspectors :ph34r:
 
...
I just used a bigger can and put two batteries in it. The high voltage terminals have snap on covers on them, so there are no exposed connections.
...

I did not see the snap-on cover you mentioned (the photo appears to show three shiny screws on the regulator's terminal strip). You are correct; it is similar to a 'can within a can'. The ability to disconnect power to the entire can, prior to opening it for servicing, is an added safety advantage.
 
...
I just used a bigger can and put two batteries in it. The high voltage terminals have snap on covers on them, so there are no exposed connections.
...

I did not see the snap-on cover you mentioned (the photo appears to show three shiny screws on the regulator's terminal strip). You are correct; it is similar to a 'can within a can'. The ability to disconnect power to the entire can, prior to opening it for servicing, is an added safety advantage.

The cover is hard to see. It does not completely cover the screws (there are holes in it for some reason). So it's still dangerous to go poking around in there with a screw driver. It would be nicer if it completely covered the terminals. I always remove power from the cabinet before working in it, (I usually unplug the power supply cord in the middle). Everything is battery backed up, so this works fine. And I would recommend anyone following my lead do the same.
 
What's the general feeling on wuench's setup?
http://www.wuench.com/Security.htm

I ended up with something somewhat similar, but I am not totally happy with my solution. I use the Elk 28" and 14" cans with the 14" below the 28". The 14" can right now has the P412 pieces, the M1G transformer and a PD9HC. I have one J-box dual-outlet that the transformer and the P412 plug are plugged into (on the Elk 14" can, both fit on a single dual-outlet).

It's all beautiful except that in the 28" can, the M1G battery is wayyy up there next to the M1G (whose holes are at the very top) and it is scary to have this huge and heavy thing in the middle of a bunch of fragile circuit boards. Especially being in earthquake land.

Sooo, wuench's solution looks very attractive. Punt the PD9H up to the 28" can and leave the 2 batteries and the P412 in the 14" can. Is there any code or electrical issue with it? Proximity of circuits, of wires, length of wires (especially the looong battery leads from the M1G to the battery in the other can). BTW, wuench, how did you the "extension cord" for the M1G battery leads?

Comments, suggestions?

Laurent
 
Anyone?
Other related question: what are my option to run the battery wire to the other enclosure? Right now, I am thinking pulling ribbed 1/2" orange tubing all the way from the M1G battery connector to the other enclosure. I assume that would be ok, but it's pretty space consuming.
Is there any other option that's less bulky? I m using a 18/2 solid thermostat wire right now for power, and that's pretty small. Just this in the huge tube is weird.

Laurent
 
BTW, wuench, how did you the "extension cord" for the M1G battery leads?

Simply replace the 18/2 that connects the battery to the M1G out of the box with a longer wire. It has spade connectors on one end to connect to the battery. You can get crimp on spade connectors at most any hardware or home improvement store or even automotive stores. They simply crimp on the end of the wire to make removing the battery more convenient. If you don't want to crimp on new spade connectors then wire nut the new wire to the old wire and use the connectors that came with the battery. The battery and the M1G are both 12V so you don't have to worry about electrocuting yourself...

Other related question: what are my option to run the battery wire to the other enclosure? Right now, I am thinking pulling ribbed 1/2" orange tubing all the way from the M1G battery connector to the other enclosure. I assume that would be ok, but it's pretty space consuming.
Is there any other option that's less bulky? I m using a 18/2 solid thermostat wire right now for power, and that's pretty small. Just this in the huge tube is weird.

Just run the battery wire with all your other wires. No need to separate it from everything else as it is just carrying 12V like everything else.
 
BTW, wuench, how did you the "extension cord" for the M1G battery leads?

Simply replace the 18/2 that connects the battery to the M1G out of the box with a longer wire. It has spade connectors on one end to connect to the battery. You can get crimp on spade connectors at most any hardware or home improvement store or even automotive stores. They simply crimp on the end of the wire to make removing the battery more convenient. If you don't want to crimp on new spade connectors then wire nut the new wire to the old wire and use the connectors that came with the battery. The battery and the M1G are both 12V so you don't have to worry about electrocuting yourself...

Other related question: what are my option to run the battery wire to the other enclosure? Right now, I am thinking pulling ribbed 1/2" orange tubing all the way from the M1G battery connector to the other enclosure. I assume that would be ok, but it's pretty space consuming.
Is there any other option that's less bulky? I m using a 18/2 solid thermostat wire right now for power, and that's pretty small. Just this in the huge tube is weird.

Just run the battery wire with all your other wires. No need to separate it from everything else as it is just carrying 12V like everything else.

I would make all connections very secure and insulated well. One 7 ah battery has about 100 A of short circuit current. If you are paralleling more than one battery you have a SIGNIFICANT amount of current available in a short circuit.

You might want to fuse the red battery lead in the small can close to the battery with a 5A fuse etc. I would. Cheap and easy way to add a level of safety (a few dollars).

Also the NEC states that Non Power Limited wiring should be seperated from Power Limited wiring by 1/4 inch. If you use the fuse and rate it 5A or less you are basically limiting the power to an acceptable level.
 
Thanks for the responses. I finally found the post saying that the battery leads could be changed on the M1, with the connectors being under the plastic cover. I did that. I also got the proper .187 connectors from Digikey (!).

But for the .25" regulation, I still did go for the orange tubing all the way from the cutout (at the bottom of the 28" can) to the M1 (at the top). It's ugly, but not too constraining.

Is there any other type of (smaller) tubing (like plain shrink tubing) that would be acceptable?

The fuse idea is pretty cool. I may look at it.


Laurent
 
Sorry to bring back an old thread, but this is something I'm dealing with. I too planned on moving the components to a flush-mounted can, when I came across this thread. I guess I'm okay with mounting the P412 enclosure (with battery inside it) inside the bigger can, but did anyone actually do this? Was heat a problem? I've seen two measurements for the depth of the P412 enclosure on the Elk website (3.25" and 3.50"). Does anyone know for sure if it will fit inside an Elk 28" can? How is the P412 enclosure mounted in the 28" can? Did you mount it such that the J box knockout in the bottom of the 28" can could still be used, i.e., raised it up a few inches in the 28" can?

Thanks,
Ira
 
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