Monitoring tripped GFCI

Does anyone have any good ideas monitoring for a tripped condition in a GFCI receptacle? I would like to be alerted when, for example, the HVAC condensate pump or basement freezer receptacles ever get tripped. I've found some GFCI receptacles that have internal audible alarms now, but I'd like to be able to learn about the fault remotely via my Elk as well.

I suppose I could plug a 12VDC transformer into the GFCI face, then connect transformer to an Elk 912 Form C board, and then do a supervisory zone. But I'd rather avoid more power-consuming wall-warts and wonder if there's a hardwired solution - perhaps a sensor along the lines of detecting 120V AC failure that can be hardwired to the load side of the GFCI.

Has anyone done something like this before?

When you wire in a GFCI outlet, there is the feed in, and there is a downstream feed that's protected by the GFCI - anything connected downstream will both be protected by the GFCI and will go on/off with the GFCI.

If you want a nice compact hardwired solution, I'd look at this Relay in a Box and wire that downstream from the GFCI, then use the contact outputs wired to a zone on your alarm panel. It should be more efficient and more compact than the transformer and 12V relay; the voltage consumed by a relay should be unnoticeable.

I came up with a circuit that can monitor a status light on an appliance, but it uses a battery (could use a wall wart instead, but you are trying to avoid those). This might be able to monitor the light on the GFCI (would have to test that).

If going with a true power-less solution is your goal, you should look into a current donut to monitor your current draw. They make DC output ones that you should be able to connect directly to your Elk, but they are not cheap. Plus you have to cut a cord to make sure only one wire is going through the donut itself.

I would say that work2play's suggestion is the simplest solution above.

what is a CFGI - something to do with a ground fault.
What does it look like.

We have RCD - residual current Devices here and they look much like a circuit breaker and trip when there is an inbalance between the neutral and active (ie ground fault or a person hanging off the wire). you can buy contact blocks that attach to the side of them that are with No or NC (or change over in some cases). use these and conenct to your monitoring system.

I have a couple of RCD's monitored this way - especially the circuit the fridge is on. We were having some mysterious trips and found the ridge off a few times so i added the contacts in and get an SMS now whenever the contact is off.

if its at the outlet itself then you can do what i did for a pump that is automatically switched on an off. i got a piggy back plug (one where you can plug in another plug into the back of it) and then rin that to a 240VAC relay (110VAC for you). The contacts are then connected to your monitoring system. This has no circutry required, just an off the shelf relay that needs to be mounted safely.

KISS

Mick

Mick

As stated, the easiest out of the box, as long as you keep wiring separated is a RIB relay on the load. No AC, relay can't stay closed. Pretty cheap also.

Thanks guys! I'll give the Relay In Box a try.

znelbok said:

what is a CFGI - something to do with a ground fault.
What does it look like.
...

Click to expand...

GFCI - Ground Fault Circuit Interrupters
Here are some samples:
http://www.leviton.c...&minisite=10251

znelbok said:

what is a CFGI - something to do with a ground fault.
What does it look like.

We have RCD - residual current Devices here and they look much like a circuit breaker and trip when there is an inbalance between the neutral and active (ie ground fault or a person hanging off the wire). you can buy contact blocks that attach to the side of them that are with No or NC (or change over in some cases). use these and conenct to your monitoring system.

I have a couple of RCD's monitored this way - especially the circuit the fridge is on. We were having some mysterious trips and found the ridge off a few times so i added the contacts in and get an SMS now whenever the contact is off.

if its at the outlet itself then you can do what i did for a pump that is automatically switched on an off. i got a piggy back plug (one where you can plug in another plug into the back of it) and then rin that to a 240VAC relay (110VAC for you). The contacts are then connected to your monitoring system. This has no circutry required, just an off the shelf relay that needs to be mounted safely.

Click to expand...

Wiring practices here are a little different. It appears a GFCI and a RCD are the same thing - they detect an imbalance in electrical flow between the hot and the neutral (In the US we only have 1 hot wire). We can do this in the breaker box with just a larger special GFCI breaker, or we can do it with an device placed somewhere along the circuit, such as those leviton outlets linked above. Once a GFCI outlet is placed on a circuit, anything wired downstream from it is protected by it as well. Our plugs don't have piggyback plugs; they have screw terminals. On a GFCI, the top set is the incoming power, and the bottom set is the downstream; but from there, what we're talking about is basically the same thing - wiring that RIB into the downstream somewhere, which is just a 120V relay in a nice package.

Might want to add some sort of time delay to this. I see a lot of potential signals or alerts when the power blinks.

gizzmo said:

Might want to add some sort of time delay to this. I see a lot of potential signals or alerts when the power blinks.

Click to expand...

Not sure what you mean, but once a GFCI trips it should stay off unless manually reset, or are you warning of the occasional power bump?

The more I think of this, the better this idea sounds as the idea is to monitor a GFCI trip and not a power bump!

Also, Winland makes a power monitor where the power has to be off for a certain amount of time (3-8 minutes) that just plugs into the outlet.

Thinking about this some more, there may be times where you want to know if you have a glitch, especially when concerned about refrigeration appliances where you would at least know they were subjected to a glitch and you could check on their proper operation.

I have a 120 VAC coil relay so I get notified on any type of failure that I just use and my HA system is battery backed by an internal battery as well as a UPS, so as long as the power is not off for an hour or so, I should be notified when it is back online.

Some good points here - like adding a 1-minute delay, and also having a second power monitor that watches normal branch power... then you can have rules that check both before alerting.

BraveSirRobbin said:

Not sure what you mean, but once a GFCI trips it should stay off unless manually reset, or are you warning of the occasional power bump?

The more I think of this, the better this idea sounds as the idea is to monitor a GFCI trip and not a power bump!

Also, Winland makes a power monitor where the power has to be off for a certain amount of time (3-8 minutes) that just plugs into the outlet.

Click to expand...

Every device that was listed, unless I missed it, was monitoring the AC output after the GFCI. Just trying to avoid getting alerts for storm related blips. If you can use rules you could use a general AC fail to shunt any GFCI alert that would follow.

Yep, I'd recommend an AND based rule, AC fail and time would be a shunt trigger, but if critical temperature based items are to be monitored, then some other programming or notification would need to be implemented. You could, also, in theory wire another RIB on a non-GFCI circuit and then use that as a modifier of a rule to shunt the GFCI notification.

Perhaps something like this to avoid nuisance glitches or momentary outages:

WHENEVER [GFCI Zone] BECOMES NOT SECURE
THEN TURN Output 99 ON

WHENEVER EVERY 1 MINUTE
AND Output 99 STATE IS ON
THEN DISPLAY "GFCI LOST POWER"
{THEN ANNOUNCE …}

WHENEVER [GFCI Zone] BECOMES SECURE
THEN TURN Output 99 OFF
THEN DISPLAY "GFCI RESTORED"



And if using an additional relay to monitor the line side branch power:

WHENEVER [GFCI Zone] BECOMES NOT SECURE
AND [Branch line-side Zone] IS SECURE
THEN DISPLAY "GFCI TRIPPED"
{THEN ANNOUNCE…}
{THEN EMAIL…}

I see the advantage of using the additional "pre-GFCI" line-side relay as a way to confirm that the GFCI is indeed tripped.


Great ideas!

(Does RIB make a double relay in a box? )