Lets set up a shrine, have a priest bless it, and charge admission.
$4.99 to see Holy Shit, with authentic authorized souvineers in the lobby as you exit.
- . Christopher A. Young learn more about Jesus .
Disregard my last. Went to Reliance's site and pulled their product sheet. See the following (and remember, this applies AFTER INSTALLATION when the unit is being used as intended)
To Activate: Switch the main breaker to the OFF position. Turn the PowerBACK switch to the ON position. The green ?System Armed? light will illuminate. When power returns to the panelboard, a 100dB alert will sound. Return main breaker to ON position and switch the PowerBACK to the OFF position.
no, it is present when there is voltage regardless of current flow. Haven't you ever used one of these?:
That voltage is present when the main breaker
no, there are manual switches like this as well:
They probably had a few calls asking the same question you were, based on their poor wording you quoted previously.
Ir does not sense current flow, because there IS none with the main switch open. It senses voltage on the line wire. when voltage comes on, it rings the alarm telling you it is safe to transfer back to mains power (and shut off the alarm)
Definitely the simplest way to determine when the power comes back on
- and the cheapest code compliant way of doing it. (not code compliant to have anything electrically connected ahead of the mains disconnect/protection device)
When they call it an electromagnetic field they are muddying the waters, because without current flow there is no "electromagnetic field" as it is generally described. It senses a low frequency electrical emission - kind of like a 60hz "radio transmission" - technically I guess an electomagnetic phenomenon -
The main breaker does remove power, from the panel. But read #2 again. They are saying that opening the main breaker makes the alarm
*stop*. Again, I don't see how turning off the main breaker affects power still being present at the incoming service wires that the sensor is wrapped around and the whole purpose of the alarm is for it to *sound* when utility power is removed. They are saying it has the opposite effect in that statement. Something there isn't right.The problem I see with your solution is I don't think it's an easy install. To add another circuit before the main breaker, probably requires a lot more work and expense. To start with, I don't think most panels, if any are rated to double tap the service conductors? Meaning, from what I see, to add your alarm circuit, you'd have to have the service conductors come into a trough box or similar, split it into two, then one set of conductors to the main panel, one set to a breaker for the alarm circuit. How did the electrician do yours?
We have a winner! I think you're correct. I was thinking of using it with an interlock type setup, but the description says manual transfer switch or generator ready load center. So, as you describe, it does work the opposite of how I thought it works. It depends on current flowing through the service conductors when power is restored. If you use it on any setup where there is no load on the utility when power is restored, eg you have the main breaker open, are using a interlock on the main panel, etc, it won't work.
Yes, for certain applications. But it's useless if you use an interlock. Also not as good if you have no generator at all and just want to know when power comes back. Some times with power outages that are expected to be short, I like to open the main breaker so that I can put the power back on after it's back for 5 mins and I see it's stable. Avoiding possible surge on restoration, or it coming back on at half-power, etc. Having an alarm that would work for that would be cool. You could use this one and open up all the critical breakers on important stuff, just leave one light circuit on and I guess that's not so bad, just flipping a lot of breakers instead of one.
I believe UC has it figued out correctly an it won't work with anything that disconnects all loads.
The question is what EMF it's detecting. UC believes it's designed to detect the EMF when current is flowing. You believe, as I did, that it's detecting an electric field from just voltage. The current approach is consistent with the testing procedure in the install instructions. From the test procedure, the alarm sounds when the main breaker is closed, ie in normal operation. And it specifically says the alarm will go off when the main breaker is *open*. That sure indicates to me that it works like UC says, ie it's looking for current flow in the service conductors. With an install that separates only some of the circuits off to a generator, when power is restored, you'd have current flowing again in the service conductors to whatever other loads there are in the house. It senses that and turns the alarm on. Open the main breaker, as described in the test procedure, the current flow stops and the alarm goes off.
I agree having it sense voltage would make more sense and make it far more useful. That's what I thought it did. But if it works that way, something is very wrong with step #2 in the install instructions, which clearly say opening the main breaker, with utility power present, silences the alarm. If it works like you think, opening the main would have no effect.
I agree with your position on how it works. I'd only point out that the above description doesn't really prove anything one way or the other. You have an EMF field from an energized conductor without current flowing. You have a different field with current flowing. The question is, which is it designed to detect? I thought it was detecting the former, that's why the test instructions made no sense. If, as you say, they are looking for current flow into the house in the circuits left connected to the utility, then the instructions make perfect sense.
I've seen whole house transfer switches for use with a generator that were manual.
It seems that the only thing all of us can agree on is that the manual or test info is somewhat confusing.
A suggestion... Several years back I installed the transfer panel manufactured by Reliance (works like a charm, by the way) and had a question. This was on a Saturday and I dropped them a note on their website. Believe it or not, I had a response later that afternoon that explained exactly and clearly the answer to my question.
That's not the real story, however. Monday morning I received a call from the company's president who was inquiring to ensure my issue had been resolved and asked if there was anything else I needed. Now THAT's customer service. I suspect that if anyone is still interested in how this detector works, a phone call to Reliance will put you on the line with somebody who can tell you everything you want to know and more.
The test isn't confusing if it works like you, and now I, think it does. The manual should have a paragraph that describes what it senses, how it works. That would eliminate confusion, people buying it for the wrong application.
For me, the key here, besides that it fits the test, is that it says it's for installation where there is a generator transfer panel or generator ready main panel. As you pointed out, with either of those, there are typically circuits that are connected to either the generator or the utility and some circuits that are connected only to the utility.
yes, and OP quoted some better language from the manufacturer.
it has been too long to remember exactly. I think there is a 400 amp main. my light tapped off of the switched side, the switched side feeds a transfer switch (as does the generator) and the transfer switch feeds the main panel.
wrong. as previously explained. it senses voltage.
Some better language that said what?
Unquestionably Confused posted (why are you not following along here?):
Disregard my last. Went to Reliance's site and pulled their product sheet. See the following (and remember, this applies AFTER INSTALLATION when the unit is being used as intended)
To Activate: Switch the main breaker to the OFF position. Turn the PowerBACK switch to the ON position. The green "System Armed" light will illuminate. When power returns to the panelboard, a 100dB alert will sound. Return main breaker to ON position and switch the PowerBACK to the OFF position.
that is exactly the right question...
there are 2 kinds of fields, electric and magnetic.
if the sensor wire does not make a complete loop, i.e if it wraps around th e panel conductor but connects into the senser electronics with only one co nnection, i.e. it wraps around but does not make a complete loop, then it i s an electric field sensor and will pick up the voltage without any current flow. Think of it as a small capacitor that senser the voltage.
to be a magnetic field sensor, the sensor wire would have to be a complete circuit that loops back into the sensor device. like a clamp on current me ter.
from the description, it sounds like it is an electic field voltage sensor, not a current sensor
and an electric sensor would be useful to detect that the grid is back on, even if your interlock switch has you disconnected from the grid and you dr aw no current
Mark
You said the "OP" UC is not the "original poster", that's Dave C. I guess it's you who isn't following along.
So we now have two directly conflicting versions from the manufacturer of how it actually works. One that clearly says it sounds with the main breaker open and the other, the install instructions, that says opening the main breaker turns it off. Take your pick. In other words, we still don't know how it actually works.
yep.
I know how it works.
Oh, really? You have one or are you a mind reader? The install instructions say it works one way, the other link that UC (not the OP) posted says it works the other. Go figure.
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