Elk Relay Wiring

[apostolakisl]

I think what both of you are talking about are just plain equipment failures, not failure as a result of some event outside of spec'd operating parameters. In the normal course of operation, everything has a failure rate. Manufacturers know their product's failure rates and they know the cost to make it lower or how much they would save if they let it be higher. They choose the failure rate to maximize profit by considering the actual cost of production and what a failure does to their reputation and future sales. As a consumer, I think you would be beating your head against a wall trying to protect yourself from these failures. Buy stuff that is made by reputable companies and use it within specs and then move on. Personally, I don't worry about putting 110 vac 10 amps on my Elk relays because Elk has a good reputation.

Focussing my efforts on protecting my equipment from over-spec events is where I think my concerns should be. Putting an extra set of relays on a sprinkler system line is not lightening protection, so I don't do it. I have had in the back of my mind that a lightening strike does put my Elk at risk becuase of my sprinkler lines. Until I just came across that rf relay, I had never seen a solution that wasn't extremely costly or had so little chance of success that it was a waste of time. If those rf relays work, I will probably buy a couple more and move my sprinklers to them thus absolutely isolating the Elk from the yard, and at a pretty reasonable price.

 

[KidCalledZero]

I hadnt logged in for a while and was surprised to see the activity on this thread.

Work2Play did a great job of explaining why I did what I did and was a contributor to the original thread when I first started planning the system.

The location of my 3 sub-panels was driven primarily by the voltage drop for the lighting system. The sprinkler system is not as sensitive to those issues but since I was placing the relays for the lighting in 3 sub-panels, it made no sense to run the sprinkler lines past the sub-panel. I have 48 relays located in the sub-panels.

The tied commons of the power supply are isolated in that the supervised side (p212s) run the cards/keypads/etc on the bus only. I use one dedicated unsupervised Elk 12V transformer for each sub-panel to power 16 relays. This way the sub-panels are as isolated as I could make them. In this part of the world, lightning is not an issue.

Below is a photo of one of my sub-panels.

Now that all the wiring is done, I get to wrestle with getting my M1 up and running. The panels are all assembled but I need to install them, wire them to the sub-panels and power it up.

Thanks again for all the help. This forum is a great resource.

 

[apostolakisl]

I can definitely see having a length of wiring issue with the low voltage lighting. A sprinkler solonoid= roughly 5 watts, an entire low voltage lighting setup, could be a 1000 watts. That is a complete game changer. To run a thousand feet of low voltage wire at 1000 watts would require a crazy huge wire guage and cost a fortune.

Personally, I would use power line controlled stuff like Insteon or UPB to swtich the low voltage lighting transformer and locate that as close to the lights as possible. At my old house I used black and decker x10 becuase they had a water proof model, and shockingly, it worked every single night. I haven't gotten to the exterior lighting on my new house yet.

Your enclosure is very pretty. How you have no cobwebs in there is a mystery to me. Is that stainless steel? And why does it look like you have two stubs of conduit on fire on the bottom side of it?

 

[KidCalledZero]

Its only a couple weeks old and it is stainless steel.

The fire duct tape was on sale.

Between audio, lighting and sprinklers I have/will run about 5,000 feet of wire outside the house. Voltage drop is a big issue.

 

[BraveSirRobbin]

I quickly browsed this thread and noticed you are using a separate 12 volt Xfrmr for the coil supply for your 16 relay box. Just watch the current rating of that Xfrmr as those coils will draw 40 milliamps at 12 volts. So if all 16 relays were turned on at once you would need 16 * 40 mA = 640 milliamps of supplied 12 volts DC from that Xfrmr (I would get one rated for at least one amp).

 

[KidCalledZero]

I quickly browsed this thread and noticed you are using a separate 12 volt Xfrmr for the coil supply for your 16 relay box. Just watch the current rating of that Xfrmr as those coils will draw 40 milliamps at 12 volts. So if all 16 relays were turned on at once you would need 16 * 40 mA = 640 milliamps of supplied 12 volts DC from that Xfrmr (I would get one rated for at least one amp).

I am using an Elk TRG-1640 which is 0.43 amps. When I sized it I used 35ma per relay (Elk spec sheet) with only 11 on at any one time. Six of the 16 relays are for the sprinkler which will only have 1 relay on at any one time. The ten relays associated with the lighting will sometimes be all powered on at the same time.

Assuming 11 at 35ma (.385 A), I am about 90% of the TRG-1640 (.430 A). Is that going to be a problem?

 

[BraveSirRobbin]

I would try it since you already have it (at least you know of the possible problem if something doesn't turn on). I try to rate my power systems for 50% usage if feasible (cost concerns). I don't know how regulated that wall wart is, so you might be getting over 12 volts anyways (depending on your line current).

 

[KidCalledZero]

I would try it since you already have it (at least you know of the possible problem if something doesn't turn on). I try to rate my power systems for 50% usage if feasible (cost concerns). I don't know how regulated that wall wart is, so you might be getting over 12 volts anyways (depending on your line current).

The TRG 1640 puts out 16.4 volts @ 0.43 amps. Is that going to help or hurt the situation?

 

[WayneW]

The TRG 1640 puts out 16.4 volts @ 0.43 amps. Is that going to help or hurt the situation?

You are confusing input and output ratings. The TRG 1640 puts OUT 45VA at 16.5 VAC, which is 45/16.5 = 2.7 Amp output. It uses .43 Amp on the 110VAC INPUT, which is about 47W. Simple transformers are about 98% efficient, so the input POWER should be almost equal to the output POWER.

11 relays "on" drawing 35 ma at 12VDC = 4.62W.

Assuming your AC->DC converter is reasonable, you should be fine as you are only using about 1/10 of the 1640s power. Are you using a single P212S for all 3 boxes? FYI. the 912 relays are 12VDC, so they cannot be driven directly by the TRG 1640, since it puts out AC.

 

[KidCalledZero]

Wayne,

Just when I thought I had this figured out.

I was planning on running the relays directly off the TRG-1640 and didnt know about the AC/DC issue. I am using the p212s to manage the power along the bus not to the subpanels. I have a number of cards and keypads on the bus that based on my calculations (which are now suspect) required additional power.

Does the p212s convert the power to DC? If so, it sounds like I need three more (one for each box) or can 1 run all three subpanels? I believe the p212s is rated for 2 amps.

Thanks

 

[gatchel]

P212's would be overkill and over priced for the 3 boxes IMHO. I would use an Altronix AL624, SMP3 or SMP5 (or Similar) depending on your needed current. You could probably get 3 of the AL624's for a third of the price of 1 P212.

 

[KidCalledZero]

P212's would be overkill and over priced for the 3 boxes IMHO. I would use an Altronix AL624, SMP3 or SMP5 (or Similar) depending on your needed current. You could probably get 3 of the AL624's for a third of the price of 1 P212.

Thanks.

The AL624 looks like it will work. Do you have a recommendation for where to purchase Altronix products online?

Now that I am thinking about this, are irrigation valves AC or DC because I was planning on running my irrigiation system directly off the TRG-2440s which I assume are AC just like the TRG-1440s.

 

[BraveSirRobbin]

WOW, good catch Wayne. I didn't realize that was an AC source as I was just trying to establish what his 12 volt DC coils draw would be from the relays and insure his 12 volt DC power supply was adequate!

An overall schematic would go a long way here towards troubleshooting and critiquing this system!

 

[Ira]

Speaking of relays and isolating irrigation zones from the databus...

Can someone tell me if my thinking on how this eight relay board on eBay works is correct?

In my setup (which is pretty strange), I have a 12VDC LED for each zone that lights up when the zone is powered. I'm thinking of using the NCD zigbee mirror contact closure transceiver and a compatible wireless/zigbee relay board to provide the isolation. The mirror transceiver would be connected to the controller side of the setup. The wireless relay board would be connected to a separate 24VAC transformer and all of the zone valves.

The eBay relay board mentioned above would provide the dry contact closure on the mirror transceiver. So, when the irrigation controller says "turn on zone 5", the zone 5 LED lights up and the eBay relay board relay associated with zone 5 is closed (via the same 12VDC connection as the zone 5 LED), which causes the NCD mirror transceiver to send a zigbee signal to the wireless/zigbee relay associated with zone 5, which causes 24VAC to go to the zone 5 valve, which causes the zone 5 valve to open.

My question is how to wire up the eBay relay board. It has 12VDC pos and neg terminals and one terminal for each of the relays (channels) for the signal input. So do I simply tap off the same 12VDC power supply that is powering the LEDs to provide the 12VDC pos and neg connections on the relay board, and run one wire from each of the LED positive terminals to the associated relay channel terminal on the relay board?

Thanks,
Ira

 

[KidCalledZero]

I just made up this "schematic" and its my first so there are going to be some adjustments.

After looking at my calculations, I did inlcude the exterior relays in the p212s circuit.

Thanks again for all the help.