Generac Generator Question

[Empty Pockets]

I have a Generac "whole house" back up generator. It came with the house, and I just got it running in the past few weeks.

It is set to run the engine once a week, to keep the battery charged, which it does.

My wife seems to think that when it does the weekly run cycle, that the power in the house should switch from city power to generator power and flicker for a second or two. I have seen nothing on that, and don't see where it would make any sense.

Any thoughts?

 

[NUTTSGT]

Does it have an automatic transfer switch ?

I'll also move this to the Lighting & Electrical Section, I believe there might a few there with some experience with these.

 

[PCustoms]

We have a generac propane setup up at camp, with an automated switch.

No flicker (or transfer as far as I know) when running the self test.

 

[wyliesdiesels]

I have a Generac "whole house" back up generator. It came with the house, and I just got it running in the past few weeks.

It is set to run the engine once a week, to keep the battery charged, which it does.

My wife seems to think that when it does the weekly run cycle, that the power in the house should switch from city power to generator power and flicker for a second or two. I have seen nothing on that, and don't see where it would make any sense.

Any thoughts?

It really depends on how it was programmed though I dont think Ive ever seen a generator setup to do a transfer during the weekly self test run.

 

[Empty Pockets]

It does have an automatic transfer switch.

 

[kwschumm]

Some generators run the weekly test at a lower RPM to keep noise down. At the slower speed any generated power would likely not be rated at the proper frequency for household use.

 

[mm08822]

The weekly startup is to circulate the oil in the engine and give indication that it is ready to run in event of a power failure. The battery is charged as needed based upon internal charger fed from house power during normal conditions. Startup does not charge the battery. The transfer switch does not transfer from utilty to generator during weekly test. If it did, everyone would complain about resetting clocks and computers shutting off b/c of the frequent power losses.
If you want the generator to start and transfer as a one time test, just shut the 200A main off in the transfer switch. Gen will start and switch will transfer gen to house. Close 200A main and transfer switch will put utility back to house and shortly shut down gen.

 

[NUTTSGT]

It really depends on how it was programmed though I dont think Ive ever seen a generator setup to do a transfer during the weekly self test run.

I know ours does during the weekly test at the fire station, that's why I asked about the automatic transfer switch. Althought that's a bit different than the residential style the OP has.

 

[mm08822]

If you don't have the manuals on the gen or transfer switch, get the model, serial #'s, and date of mfr and i should be able to get for you. PM me the info. Transfer switch data is usually in upper left side corner of enclosure.

 

[Empty Pockets]

If you don't have the manuals on the gen or transfer switch, get the model, serial #'s, and date of mfr and i should be able to get for you. PM me the info. Transfer switch data is usually in upper left side corner of enclosure.

Will do, work has me out of town for a couple of weeks. I'll send that information when I get home

 

[FreedomPenguin]

The weekly startup is to circulate the oil in the engine and give indication that it is ready to run in event of a power failure. The battery is charged as needed based upon internal charger fed from house power during normal conditions. Startup does not charge the battery. The transfer switch does not transfer from utilty to generator during weekly test. If it did, everyone would complain about resetting clocks and computers shutting off b/c of the frequent power losses.
If you want the generator to start and transfer as a one time test, just shut the 200A main off in the transfer switch. Gen will start and switch will transfer gen to house. Close 200A main and transfer switch will put utility back to house and shortly shut down gen.

hes right, the house i just bought (havnt moved in yet) has a 8kw generac on the house, it turns on weekly. but the owner told me it does it test every monday at noon, but it doesnt transfer power for test. only when the power is out for a while during an actual outage.

I am not sure if I want to turn it off or keep it running though. OP and others, do you like your generac/generators?

 

[hardwareguy2068]

I have a 22KW that we installed almost 3 years ago. To answer the OP, mine tests every Sunday at 1 pm and runs for 5 minutes with no transfer to the house. The idea is to simply test the unit to make certain everything is in order in the event the utility power is off and it needs to generate power. We have used ours only 6-8 times in the past 3 years.....but I have to say, it is awesome to have the power in the dead of winter and it is bone chilling cold outside. We have Geothermal heat so that is the need for the large unit as it operates our entire house.

Hope that helps...

 

[woodzy]

You wouldn't want to have it be transferred to the house or you will be resetting all the electric clocks every week during the transfer. There is a few seconds lapse time from where you need it until when it is really ready to supply you good clean power.

 

[Junkman]

The generator will start and run for the prescribed "test" time period, without transferring to the home, however, should there be a power failure while it is doing its test, the automatic transfer switch will immediately switch to supplying the house with power.
I haven't set up my generator to run on the test mode, because I would prefer to be there, to manually test it and check for other issues at the same time. I ran my generator yesterday due to a power outage, and since I don't have it set up for automatic, I have to manually start and stop the generator. When I went out to turn it off, I found that it had developed a leak in the fuel line. If it had been on automatic testing, it could have gone through multiple cycles, spilling fuel on the ground, and the leak could have gone unnoticed for weeks.

 

[mjeff87]

Some generators run the weekly test at a lower RPM to keep noise down. At the slower speed any generated power would likely not be rated at the proper frequency for household use.

^^^this is true for Generacs

I will load test mine about every 2-3 months (by opening the main breaker like mm08822 mentions) unless I experience a power outage in the interim.

I have a 20KW, and it was/is the best money I ever spent. Going on 7 years now without a single problem. I do service it annually (oil/filter/plugs) whether needed or not). Cheap insurance to make sure it functions when needed.

 

[pinkerton]

"transfer of loads does not occur during exercise" - so no flcker. But why run it every 7 days for 20 min - what's this do to your gas bill? I'd reconsider this routine for another battery charging method

3.6WEEKLY EXERCISE CYCLEThe generator will start and exercise once every 7days. During this weekly exercise, the unit runs forabout 20 minutes and shuts down. Transfer of loads to generator output does not occur during the exer-cise.

 

[APEowner]

I know ours does during the weekly test at the fire station, that's why I asked about the automatic transfer switch. Althought that's a bit different than the residential style the OP has.

A friend of mine owned a decommissioned fire house and it always startled me when I was there all alone on a Saturday when the generator would startup on its self test. Nothing like the scare I got when the siren that was still on top of the building would go off at noon!

To partially answer the OPs question, I've seen them self test with transfer, without transfer and some that were programmable to do either. In other words, get and read the manual.

 

[pinkerton]

I copied the manual above (should have mentioned that)

 

[kwschumm]

"transfer of loads does not occur during exercise" - so no flcker. But why run it every 7 days for 20 min - what's this do to your gas bill? I'd reconsider this routine for another battery charging method

3.6WEEKLY EXERCISE CYCLEThe generator will start and exercise once every 7days. During this weekly exercise, the unit runs forabout 20 minutes and shuts down. Transfer of loads to generator output does not occur during the exer-cise.

It's no different than a car. Just sitting for a long time causes problems. Say a circuit board goes bad (yes, components age and fail even when they are not used), or your board fails due to non-leaded solder whiskers growing, or a solder joint breaks just due to thermal cycling, or a mechanical linkage sticks through oxidation, or a hose breaks down and causes a blockage, or a rat climbs into the generator and chews the wires. You want it to be tested so if a problem occurs you can get it fixed before an outage occurs.

 

[pinkerton]

It's no different than a car. Just sitting for a long time causes problems. Say a circuit board goes bad (yes, components age and fail even when they are not used), or your board fails due to non-leaded solder whiskers growing, or a solder joint breaks just due to thermal cycling, or a mechanical linkage sticks through oxidation, or a hose breaks down and causes a blockage, or a rat climbs into the generator and chews the wires. You want it to be tested so if a problem occurs you can get it fixed before an outage occurs.

I understand (and agree somewhat), yet suggest that once a week for 20 min is excessive. My rough math says that will cost about $100/year. The product should be robust enough to limit the points you make above.

 

[mm08822]

Generac home standby units have evolved with several versions of software and controller boards. New models today give the option of: 1week, 2 weeks or 1 month exercise frequencies. The 8kws run for 12 mins and bigger ones run for only 5 mins. Also as earlier stated, newer units can be selected to run at a lower "quiet" speed if desired - like 2400 or 1800 rpm depending on size.
You can also put the unit in off mode and defeat the entire standby and exercise option, but that's a little risky!

 

[kwschumm]

I understand (and agree somewhat), yet suggest that once a week for 20 min is excessive. My rough math says that will cost about $100/year. The product should be robust enough to limit the points you make above.

"Should be" is a nicety that often doesn't survive the value engineering phase of product development.

 

[pinkerton]

Generac home standby units have evolved with several versions of software and controller boards. New models today give the option of: 1week, 2 weeks or 1 month exercise frequencies. The 8kws run for 12 mins and bigger ones run for only 5 mins. Also as earlier stated, newer units can be selected to run at a lower "quiet" speed if desired - like 2400 or 1800 rpm depending on size.
You can also put the unit in off mode and defeat the entire standby and exercise option, but that's a little risky!

Good to hear. I've always flirted with the idea of getting one, so this helps. Although I still like the "cheap" option of using a portable and a dryer plug

 

[checkthisout]

The transfer switch only changes if manually switched or if there is a loss of line power.

 

[wyliesdiesels]

Good to hear. I've always flirted with the idea of getting one, so this helps. Although I still like the "cheap" option of using a portable and a dryer plug

There is so much wrong with that....

 

[ishiboo]

The problem is that those transfer switches do not synchronize the power with the line, so each time it exercised you would have the potential for computers/clocks/etc. to be reset, damaged, etc. So while exercising under a load would be better for the generator engine, it's not practical on those sets.

The goal though makes a lot of sense - at least you know the engine will run. It's important for it to run long enough to get the oil temperature up and burn off any condensation/etc.

 

[snapon12]

. Programmable transfer switches can be set to transfer load under a test, however most homeowners and businesses don't set them up that way. Usually they call wpi Stuart and Stevenson or the like to do a load test and real transfer at say 2 am or a holiday when there not in business. If your unit is transferring a load to test you may want to have the local generac dealer come and give it a look see. I worked for generac, Kohler and marathon for years. In that time I learned fast that with transfer switches you best know what you are doing. I went to a call where a switch transfered city power and the genset power at the same time. The set was 1500kw. There was a very large hole in the cender block wall where the switch was.

149 r/c worx team driver

 

[MikeF2316]

. Programmable transfer switches can be set to transfer load under a test, however most homeowners and businesses don't set them up that way. Usually they call wpi Stuart and Stevenson or the like to do a load test and real transfer at say 2 am or a holiday when there not in business. If your unit is transferring a load to test you may want to have the local generac dealer come and give it a look see. I worked for generac, Kohler and marathon for years. In that time I learned fast that with transfer switches you best know what you are doing. I went to a call where a switch transfered city power and the genset power at the same time. The set was 1500kw. There was a very large hole in the cender block wall where the switch was.

149 r/c worx team driver

Sometimes you get a rocket scientist in your Facilities department that decides that 10:30 am on a Tuesday is a good time to do a test! It was a brand new unit that didn't work the first time it was needed. So the next week they thought they had fixed it and did this test.

The Facilities guy said he thought our lights would just flicker when he turned the main breaker for our building off. Of course no way would that have happened, even if the generator had been repaired properly...

 

[TractorJeff]

LOL!
Big hole in the cinder block wall!
Don't you hate it when your out of phase!
Syncing to the Utility can be tricky as they are infinite power and you are a grain of sand on the beach!
Saw it happen just once, fire came out of the breaker and the generator diodes let the smoke out! They got lucky they didn't break the crankshaft trying to pull into sync!

 

[snapon12]

Ouch, this site was up and running for 3 years or so. We figure that the switch was adjusted by someone at the facility or the switch had a failure. Maby a bad contacter. Idk there wasn't enough left to troubleshoot. Lol

149 r/c worx team driver

 

[Empty Pockets]

hes right, the house i just bought (havnt moved in yet) has a 8kw generac on the house, it turns on weekly. but the owner told me it does it test every monday at noon, but it doesnt transfer power for test. only when the power is out for a while during an actual outage.

I am not sure if I want to turn it off or keep it running though. OP and others, do you like your generac/generators?

I haven't had an outage yet, but I like the peace of mind

 

[Bigbandguy]

I have a 17.5 KW Generac and am quite fond of it. It simply works.. we did have an early issue with the float charger not keeping the battery up... the charger is on the transfer board and if the leads are over a certain length there is too much voltage drop to keep up the battery. We fixed it by replacing the twisted pair to the battery with #14 romex... end of problem. This will not happen in most installations but ours was placed some distance from the panel. We were out half a day recently and didn't have time put the book down before the lights came back from the Generator. One ice storm will definitely pay for its maintenance in comfort and peace of mind.

 

[wyliesdiesels]

I have a 17.5 KW Generac and am quite fond of it. It simply works.. we did have an early issue with the float charger not keeping the battery up... the charger is on the transfer board and if the leads are over a certain length there is too much voltage drop to keep up the battery. We fixed it by replacing the twisted pair to the battery with #14 romex... end of problem. This will not happen in most installations but ours was placed some distance from the panel. We were out half a day recently and didn't have time put the book down before the lights came back from the Generator. One ice storm will definitely pay for its maintenance in comfort and peace of mind.

thats not a code permissible use of Romex.

And twisted wire is not good for DC electricity.

 

[Empty Pockets]

I got home, and was doing some work in the basement shop. Last night (Sunday) the unit fired itself up for 5 minutes @ 7:00 PM, as per usual.

This afternoon, we had an unexpected power outage, after a couple of seconds, the back up generator fired up,and the house switched over to generator power.

All's well and more important, the wife is comfortable with my service and repairs to the motor.

Thanks to all for your imput

 

[TractorJeff]

Why isn't twisted pair acceptable for DC?
Its probably what Generac puts on there chargers?

 

[wyliesdiesels]

Why isn't twisted pair acceptable for DC?
Its probably what Generac puts on there chargers?

I personally have seen batteries drain when hooked up with twisted wiring. The inductance between the wires creates a load on the batteries.

Use to live off grid and made the mistake of using an extension cord(twisted conductors) to hook up a 12v RV fridge. Watched the run time on the battery bank decrease immensely.

Switched to individual conductors and got my usual run time back.

 

[pentavolvo]

I personally have seen batteries drain when hooked up with twisted wiring. The inductance between the wires creates a load on the batteries.

Use to live off grid and made the mistake of using an extension cord(twisted conductors) to hook up a 12v RV fridge. Watched the run time on the battery bank decrease immensely.

Switched to individual conductors and got my usual run time back.

We use a lot of 12 and 24vdc in an industrial application at work and slot of it is in twisted pair but these also aren't small 12 volt battery's