Running water treatment systems off backup generator power

[WellOff]

Please excuse me if this is covered somewhere (I'd looked but didn't find anything).

In general the question is whether common household water pumping, filtration and treatment systems can operate under backup generator power. There seems to be a fair amount of electronics embedded in some of this stuff.

I am pretty sure that well pumps themselves are likely OK. In my case, and more of my concern, I have a Stenner pump and a Fleck sxt7000 backwash filter. The Stenner is plugged in to a small surge protector (in the outlet receptacle). The Fleck is plugged directly, w/o any such surge protector (not sure if I could get two on that outlet).

My generator is an older [circa 1993] Onnan/Cummins, diesel (Kubota) 7.5kW. I've tested this generator under load and find that it seems to produce very stable output: runs at 60HZ to 61HZ; voltage is also very stable (though I don't recall what the ranges were- I was thinking that the HZ was a bit more critical). This generator will serve my backup power needs just fine: my well pump is only 1/2hp (35' well). My electrical connections are all vetted.

Before I go to throw the switch to do a cut-over test of my generator I'd like to have confidence that I'm not going to fry any of my water equipment. I know to protect my computing equipment: all run off of UPSes, and I figure that I'll see what my household appliances think about this.

 

[Valveman]

A 2KW generator would probably run that well pump and equipment. So a 7.5KW gen set can run the pump and probably most other things in the house at the same time. I will move this to the softener forum to see if anyone there has a problem with the rest of the system on a generator.

 

[Sponsor]

 

[Mikey]

I ran my system in Florida for several years on an older Generac (model number 0052830, purchased 2/2007). I never had problems, but I also had an older Fleck 2500 system, which didn't have very fancy electronics. OTOH, my newer high-tech air conditioner and most electronics in the house, had LOTS of problems, due to the dirty power produced by the generator. If you can find out the rated Total Harmonic Distortion (THD) of your generator (or measure it), someone might be able to tell you whether it's too high for your gear. The general rule is less than 6% THD is OK, but the lower the better. I have a portable generator in my current home which claims 5% THD, and have none of the old problems with anything. For more information: http://powerupgenerator.com/total-harmonic-distortion-portable-generators/.

 

[Bannerman]

To my understanding, UPS units have some ability to condition dirty power. Since you are concerned with harm to the control valve electronics, you could obtain an appropriate capacity UPS for the water filter and Stenner.

As you're mostly concerned with using the generator for back-up power as opposed to continuous power, I would suggest not powering the water filter from the generator. Back washing a water filter is usually not required every day, so delaying backwash until power is restored is probably not critical. If the well pump and Stenner receive power from the generator, your water system will likely remain fully operational through a moderate length outage.

Since filter backwash is typically programmed during the night when you're sleeping, unless the power fails while the filter is already backwashing so that it can't advance to the next cycle, getting out of bed to run a generator is likely not a priority, especially if the outage is short duration.

 

[Mikey]

UPS units have some ability to condition dirty power

Yes, some units and some ability. I had some older APC units in the house and all they did on generator power was beep at me. There were options on some of them to accommodate some degree of bad power, but I never pursued them.

 

[Reach4]

I am pretty sure that well pumps themselves are likely OK.

The Franklin AIM manual has suggestions on generator minimum sizing to start and run a pump.

They say to allow for 50% more power if using a 2 wire pump. For example, for a 1 HP 3-wire pump, they say that an internally regulated generator should be rated for 2.5 kW and 3.13 kVA.

 

[WellOff]

As noted, I am not concerned with how MUCH power, just the quality.

The backwash filter, though not performing cycles all the time, is still on and drawing power.

I don't have a lot of room in my pump house to house a UPS. I suppose I could figure out shoehorning one in if needed, but before I go that route I'd like to have a reasonable notion that it's required.

For what it's worth, here's the specs on my generator:

GENERATOR DETAILS
Type .................................................. ...........Onan, YD revolving field, 4-pole, brushless
Phase .................................................. ........................Single
Standby Ratings (60 Hertz) ........................................... 7.5 kW (7.5 kVA @ 1.0 PF)
Voltage Regulation Under Varying Load: .............................3 Hz maximum
Frequency Regulation Under Varying Load (60 Hz)...............+-5 percent
Random Voltage Variation: .................................................+-2 percent

GENERATOR SET DETAILS
Engine Speed (60 Hetrz) .................................................. ........1800 r/min

I'm just not finding any reports of any problems: even with general appliances (with electronic circuitry), unless run off of really cheap generators (mine is not a cheap generator). Seriously doubt that this is because no one is running such equipment off of generators, in which case I am tending to think that this is a non-issue.

 

[Bannerman]

The backwash filter, though not performing cycles all the time, is still on and drawing power.

Without power, the filter will continue to filter water passing through. The controller electronics are mainly for keeping time and when backwashing is scheduled to occur, to control the motor to move the piston which alters the water path during the backwash cycle.

Since the SXT controller is equipped with a capacitor to provide backup power to maintain program settings, you should not need to reprogram but may need to reset the clock after a power outage. Even if using the generator to power the filter, since generator power is not immediate, unlike a UPS, you may need to reset the clock regardless.

 

[WellOff]

Bannerman, yes, the filtration will still continue. And, yes, it's a matter of power to maintain clock time (for performing the scheduled backwash cycling). I've had many power outages and have never had to touch any of the equipment, thank goodness! (has been a VERY reliable system- running now for 4 1/2 years) So, no worries about dropping power (for a brief time).

 

[ditttohead]

I have seen a lot of problems with running off of generators and inverters in the past. My knowledge is extremely limited in this field so I will only give you the tiny bit of information that I have had to figure out in the past. I learned a lot of this from doing Christmas parades with jeeps and extensive computer controlled lighting systems.

The inverters or generators need to have a good sine wave. Without a good sine wave many electronics will not work. Even simple items like heating blankets can have problems with bad power. I was unable to get my computer controlled lighting system to work off of my generator or my inverter until I went to a more expensive sine wave inverter.

Below is an example.. And Merry Christmas!

 

[WellOff]

Yeah, electronics can be sensitive. That's why I'm here asking about the filtration equipment. Not sure that it's all the complex, though it has clocking, and it's clocking/timer functions that tend to rely on stable power (Hz wise). An interesting read:

http://www.fieldlines.com/index.php?topic=147181.0

I'm planning on running my generator and seeing how things go. Had a bit of a bout with a coolant temperature sensor: broke the old one off in the head and had a battle getting the remains out. Set me back (now am ordering some new fuel lines and primer bulb).

 

[WellOff]

Oh yeah, dittohead, I'm STILL planning on switching to Katalox Lite. Been a very busy year and no time; next year I've got household type projects on the radar. Might look to get a new tank to make the change-over quicker: and this way should I find that it doesn't work out I can just swap the carbon tank back.