MisterBill2 said:

If the generator is not connected to the mains, then there is no current flowing to produce an output from a current sensor of any kind. And, during an exercise the transfer relay does not operate, hence no real current.

The no-current state is a key indicator something is wrong. We know the exercise schedule. If the gen is running outside the schedule and there's no current sensed, then you likely have a xfer switch fail, and, you'll be getting calls at 2am that the facility is lit up by battery emergency lighting.

The solution from the xfer switch box (which OP prefers), is two sensors, sensing a voltage (gen is running), and sensing some amps via a pickup coil (xfer switch working as expected).

 

Go plug in a 60Hz wart into a 40Hz source, see what happens.

Probably, nothing bad. The majority of wall warts produced today are switching power supplies with universal inputs. These are rated for normal operation down to at least 50 Hz, usually down to 45 Hz, and some are rated for a 0 Hz (DC) input. The real concern is the applied voltage. Many switcher controllers have UnderVoltage LockOut (UVLO) protection. For this reason, connect the switching wall wart across the two Lines, not from Line to Neutral. It will run just fine on 180 V.

A linear wall wart also would work. At 40 Hz you would not be able to get the full rated output power, but that doesn't matter in this application.

ak

 

MisterBill2 said:



The no-current state is a key indicator something is wrong. We know the exercise schedule. If the gen is running outside the schedule and there's no current sensed, then you likely have a xfer switch fail, and, you'll be getting calls at 2am that the facility is lit up by battery emergency lighting.

The solution from the xfer switch box (which OP prefers), is two sensors, sensing a voltage (gen is running), and sensing some amps via a pickup coil (xfer switch working as expected).

The TS request was a system to verify that the engine had started and was spinning the generator. The additional benefit of knowing that the connections were OK was my addition, since that information is free.

 

It's a 1ph CT gen. center tapped.

Right. I understood what you meant and was explaining it to someone else. I was simultaneously trying to explain to you, that "CT" doesn't just mean "center tap." More frequently it means "current transformer.

 

MisterBill2 said:



The no-current state is a key indicator something is wrong. We know the exercise schedule. If the gen is running outside the schedule and there's no current sensed, then you likely have a xfer switch fail, and, you'll be getting calls at 2am that the facility is lit up by battery emergency lighting.

The solution from the xfer switch box (which OP prefers), is two sensors, sensing a voltage (gen is running), and sensing some amps via a pickup coil (xfer switch working as expected).

It has been repeated too many times already. The transfer switch does not switch over during the exercise. The generator output does not get connected to anything. There is no current.

 

There is no current.

There is no current being drawn and there is no current available to be drawn are two different things. I think there was something earlier about the generator not making any output, but then the TS posted measurements taken during the maintenance run.

I think it is clear now that during maintenance run, the generator is disconnected from the building, but the coils are energized and can power a sensor system.

ak

 

It has been repeated too many times already. The transfer switch does not switch over during the exercise. The generator output does not get connected to anything. There is no current.

You missing the states the gen can be in. Two sensors get you all the info you need.

Yes, you should expect no current sensed during scheduled exercise runs.
But what if there is current sensed during an exercise run? Ut O, better go look, sum-tin is not right.
Or what if there's no current sensed when the gen is running and it's not exercise time? Ut O, better go look, sum-tin is not right.

You see it now?

 

Probably, nothing bad.

Well, this is AAC, so experiment, see what happens. Be sure to monitor output waveform and voltage on some load, and monitor temps.

 

You missing the states the gen can be in. Two sensors get you all the info you need.

Yes, you should expect no current sensed during scheduled exercise runs.
But what if there is current sensed during an exercise run? Ut O, better go look, sum-tin is not right.
Or what if there's no current sensed when the gen is running and it's not exercise time? Ut O, better go look, sum-tin is not right.

You see it now?

I see you are addressing things that outside the scope of OP request. The exercise is not a test. There is no pass/fail. TS just wants to know when the exercise happens.

 

I see you are addressing things that outside the scope of OP request. The exercise is not a test. There is no pass/fail. TS just wants to know when the exercise happens.

From a scheduled run perspective, the exercise run is indeed a test, it should start and run. If a sensor you add indicates the scheduled exercise did not run, that means there's an issue, the exercise test failed for some reason.

This from post #57.

I just want to know if the generator is running, either in exercise or due to an outage. I have a UPS/Raspberry plus power monitors on some 3 phase motors that will notify me of any real outage.

So, for that all you need is a volt detector. But I think it's also important to know if the xfer switch also worked, so for that you add a pickup coil to detect amps. A floating gate FET that is tuned right, makes for a easy contactless volt detector, but surely one of many options that will work.

Now I need to go back and see where the x-420 came into the chatter.
Post #65

The signal would be going into one of the analog inputs on this https://controlbyweb.com/x420/

 

This from post #57.

I just want to know if the generator is running

Thank you for finding where he said that.

Now that we are on the same page about what the goal is, I don't understand why you keep going down this road:

it's also important to know if the xfer switch also worked

TS never said anything about that. If you're going to add your own criteria to the "test" then why this in particular? Why not insist on monitoring the frequency of the generator? The oil pressure of the engine? Power factor? Load balance? All of the above?

the exercise run is indeed a test

Maybe it is, from the angle you're looking at it. But maybe that's irrelevant from the angle the question is being asked. Maybe TS just wants to know when that engine is running so he can open a vent before his dogs die from carbon monoxide poisoning.

This thread is going on several pages now, talking about things that TS apparently has zero interest in, as he hasn't addressed any of the superfluous material that has been presented. I'm just saying, maybe it's not worth continuing to kick this particular horse.

 

Thank you for finding where he said that.

Now that we are on the same page about what the goal is, I don't understand why you keep going down this road:



TS never said anything about that. If you're going to add your own criteria to the "test" then why this in particular? Why not insist on monitoring the frequency of the generator? The oil pressure of the engine? Power factor? Load balance? All of the above?



Maybe it is, from the angle you're looking at it. But maybe that's irrelevant from the angle the question is being asked. Maybe TS just wants to know when that engine is running so he can open a vent before his dogs die from carbon monoxide poisoning.

This thread is going on several pages now, talking about things that TS apparently has zero interest in, as he hasn't addressed any of the superfluous material that has been presented. I'm just saying, maybe it's not worth continuing to kick this particular horse.

The purpose for monitoring is to know what the gen is doing. OP already said it had a fail-to-start issue in the past, so sure, 1st main goal is to know if it's running at all. The additional amps sensor simply provides more attributes to the monitoring, aka various states the gen can be in. OP also stated use of an X420 DAC, so it kinda makes sense to monitor what you can to have remote visibility into the running state of the gen. Running in exercise, running full speed no power, running full speed with power.

This is just a web forum, kicking the horse is because we can, regardless if OP returns or not. I simply do not recall, what would you suggest to monitor running or not, from within the xfer box?

 

what would you suggest to monitor running or not, from within the xfer box?

Personally I liked the oil pressure switch (if it is not a kill switch but instead has a constant low voltage applied to it) and/or your idea of the air paddle switch. But TS wants this signal to come from the transfer switch location and seems convinced that this measured voltage is a reliable signal (despite probably only existing as an artifact of residual magnetism) so under that constraint I think the cheap switching wall wart is the simplest and best answer. Most of these will output a steady 5V "signal" (power) with any input voltage between 100V and 240V and don't care about frequency. If TS like most people over 30, they probably have a box of chargers in a closet somewhere meant for unknown/forgotten devices that can't be thrown out because a day later the device will found and needed. So it should be free (or $7 on Amazon if not) and no circuit assembly required whatsoever.

IMO If the generator output voltage drops below 100V when a wall wart is plugged into it; if it can't power a wall wart that isn't powering anything but a microcontroller input, then it is too flaky to base anything critical on. Too flaky even to provide a "FYI" notification of no importance. A floating gate transistor or a neon opto might work if the wall wart doesn't; it might work, until it doesn't. Flaky. Even the wall wart is flaky even if it works. But it is the best solution I've seen proposed given the constraints TS has imposed.

 

Certainly these are tests to verify that the engine is able and willing to both start and run. That was first stated right near the very beginning of this thread, the reason being that there had been a long stretch of crank till the battery died without a start.
Checking at the transfer box is preferred because the generator itself is far away in a less convenient location. That means any additional wires would be expensive and a lot of effort. Detecting of the generator output, stable or not, is a certain indication that it has actually started and run up to some speed. THAT VOLTAGE is already connected to the more conveniently located transfer box.
So while sensing oil pressure is probably a valid way to verify running, it would be a far more expensive method.
AND the TS and others have verified that sensing the output voltage at the transfer switch works.
SIMPLE, Easy, and Cheap, plus adequate for the requirement.

 

what would you suggest to monitor running or not, from within the xfer box?

Post #27.

ak

 

So while sensing oil pressure is probably a valid way to verify running, it would be a far more expensive method.

I don't think it's a valid method. I suspect there will be oil pressure during cranking, and if the gen fails to run due to bad fuel or whatever, then you detected a false state.

If you could sense at the gen, one spot to look at is the voltage on the battery. You can sense a low batt that might be failing to charge properly, and at the same time sense a charging voltage which would indicate the gen is running. The fail mode there though is if the gen batt charging fails, you could have gen running but it's not charging the battery. This might be doable using the Rf device OP had listed, but it's an active style sensor, meaning it needs to use power to sense, and that power has to come from somewhere.

I might suggest even a 3rd sensor, to detect when util mains have failed. You can use the floating gate FET as a sensor (or one of the other methods mentioned), placed near or on util mains. You need this 3rd one to determine a failed gen start during util power fail. If you sense no e-field (or no volts) from util mains, AND, you don't get a "gen running = true" sense, then that means the gen failed to start. Maybe the gen failed to start due to battery going south, or maybe something goofed in gen spark or timing. This is probably the worse case scenario, but good news is, you can sense that state fairly easy.

 

CUMMINS is a larger company that has employees all over and their own stocking warehouse facilities. Cummins is also well known in industry as a reliable company with reliable products.

i seem to remember you putting Generac down because they need the valves adjusted. Cummins/Onan generators also need valve adjustments too. Both engines are overhead valve engine with solid lifters. Like al engines of that type from cars to lawn mowers the overhead valve train need valve adjustments from time to time, unlike the old flathead engines of the Briggs or Tecumseh engines.

 

i seem to remember you putting Generac down because they need the valves adjusted. Cummins/Onan generators also need valve adjustments too. Both engines are overhead valve engine with solid lifters. Like al engines of that type from cars to lawn mowers the overhead valve train need valve adjustments from time to time, unlike the old flathead engines of the Briggs or Tecumseh engines.

Not quite right, but it was rather strange that it was in the basic user instruction book, while not much was mentioned about the actual generator.
The bigger thing with Generac is that it is a sales company rather than a full support company. The installations and service are done by contractors rather than employees. And service parts are seldom on hand is the other complaint that I have heard.

 

Mine is 6 years old and zero problems with service, mainly because my area has multiple long-term companies to choose from. The battery was replaced under warranty after 1 year (bad batch). Other than that, nuttin. Earlier this year it ran for three days with no problems. The annual maintenance was earlier this week - no extra oil consumption, no valve timing adjustments.

ak

 

WOW! All this banter back and forth about volts, current, transfer switches and such just being hashed and rehashed over and over again. Back in post 79 a thermocouple in the exhaust stream was mentioned. Post 87 offered an even better idea, using the Oil Pressure Sensor. So far none of those suggestions gained any traction with everyone arguing about whether there's voltage or current or hertz and on and on and on. Well, here's another (dumb) idea: Put a microphone inside the machine. It's GOT to be making some noise when it's running. And as for ambient noise - turn the sensitivity down so that it only picks up the sound of the engine. At that point who gives a darn about volts, current, transfer switches or the price of tea in China. What ever happened to the KISS approach? (Keep It Stupidly Simple)

As for TC's (thermocouples) they're cheaply available at hardware stores in the water heater section. They obviously produce enough current to keep gas valve open. But the oil pressure sensor seems to me to be the best approach I've seen thus far. And at this point we've gone WAY too far arguing about who's right regarding outputs. None of that mattered to the TS at the outset of his/her thread. "Sensing when generator is running" is all that was asked of us. Let's not invent a Rube Goldberg device. SHEESH!