Power alert relay

[gfs]

I run my ELK and HS equip thru a UPS so i dont get an alert when AC power fails...  is there a relay i could get to plug into non-backup outlet,  simple on off power that i could tie into my Elk output?

 

[BraveSirRobbin]

I use a relay with a 120 volt ac coil and just soldered an extension cord (that had a fuse build in to the plug) cut off on the 'plug' end and then just had the contacts go to an Elk zone.  (Relay is over-kill, but easy to wire with the terminals on the socket).
 
You can also use a wall wart and use the appropriate (usually DC) coil relay as well.
 
http://www.allelectronics.com/make-a-store/item/RLY-2120/120-VAC-DPDT-10-AMP-RELAY/1.html
 
http://www.allelectronics.com/make-a-store/item/RST-2/8-PIN-MIDGET-RELAY-SOCKET-SCREW-TERMINALS/1.html
 
------------- or --------------
 
http://www.allelectronics.com/make-a-store/item/PS-12225/12-VDC-1.25A-SWITCHING-POWER-SUPPLY/1.html
 
http://www.elkproducts.com/product-catalog/elk-912-compact-relay-module-12-volt-dc-coil

 

[gatchel]

Relays work well. If you don't want an exact moments notice when the power goes out the following works very well and has a built in delay for when you have those minor power blips.
 
http://www.winland.com/products/Power-OutAlert/poweroutalert.html

 

[BraveSirRobbin]

Relays work well. If you don't want an exact moments notice when the power goes out the following works very well and has a built in delay for when you have those minor power blips.
 
http://www.winland.com/products/Power-OutAlert/poweroutalert.html

I have a few of those units and wound up not using them as the delay was pretty long (can't remember how long as this was several years ago; but it was enough lapsed time that I thought the unit was broke).  I opened one up to see what was inside it and it looks like one huge power resistor shaped item, that I believe might work off of heat??? (Not sure if that was a relay or not).
 
Anyway, because of the long delay, I just used a relay and gave notifications when the power went off, then back on.  If you don't want notifications on potential glitches you could probably do something with rules (don't send any notifications unless device has been off for xxx seconds).

 

[BLH]

Sales page says 3-8 minutes.
I also believe it is just a thermal time delay relay. That closes when it cools down.

 

[gatchel]

Sales page says 3-8 minutes.
I also believe it is just a thermal time delay relay. That closes when it cools down.

 
 
It is a resistor and a thermal switch attached to each other.
 
It was just another option. I have had sites where the customer wanted the relays we installed ripped out and these installed because of the longer delay. We typically used these in installations where maglocks were installed on exterior doors. The thought was that they couls care less about the small outages. The longer outages where the battery backup could run out was where we were concerned.
 
Rules definitely would be able to accomplish the same thing asw BSR mentioned.
 
One other thing to remember is that there is also a delay when the power comes back on. I think it is shorter but the resistor has to heat the thermal switch back up...
 
A wall wart, the right size capacitor, and a relay could also give you a built in delay to help elmininate the short power blip notifications.

 

[BraveSirRobbin]

A wall wart, the right size capacitor, and a relay could also give you a built in delay to help elmininate the short power blip notifications.

Good point.  The "RC" time constant of the coil resistance of the relay chosen paralleled with a capacitor could give you the hundreds milliseconds or so of glitch protection.
 
Also, you could just run a DC wall wart with a capacitor directly into a zone and measure the analog voltage, then give notifications if that value goes say to half.

 

[Del91574]

We do this all the time to supervise shunt breakers...RIB relay then use the dry contacts for monitoring. If you need to time delay, if you don't have the ability in the host controller, use something like a 6062 to delay the output as a one shot.