UPS Battery Backup Problem

jebatty · Feb 1, 2012

I haven't seen this mentioned in any of the threads I've read on battery backup for boiler controls and circulators, so here goes. I changed my backup from a 400 watt modified sine wave inverter operating on a 12V battery, which require manual switchover, to an 800VA UPS computer style backup operating on 24 VDC (2 x 12 volt batteries in series) which automatically switches over. I changed out the internal batteries to 2 - 104ah gel cells.

The good news is that on a power failure the switchover went fine, boiler continued to operate and circulators continoued to run, although the circulators (15-58, 009 and 007) emitted an audible buzz. The Kill-o-watt reported 111VAC; our normal line voltage is 120-122AC, and a little less than 400VA.

The bad news is that the UPS modified sine wave would not cold start the 15-58. I tried to start the system on the UPS backup, and the boiler controls lit up, the 15-58 emitted a buzz, but there was no flow. Speed setting was M, I switched it back and forth a couple of times between M and HI, and then it started. As best as I could tell the 009 and 007 started up OK.

I'm guessing either that the UPS could not provide sufficient start up current, or that the 15-58 doesn't like modified sine wave much at all, or both. From what I have been able to find is that motors will run hotter under modified sine wave and may emit a buzz, which these circs definitely did, and that modified sine wave may not be good for some motors.

Anyone else experience a similar issue? Or can try a cold start on the UPS and see if they have an issue? A pure sine wave UPS may be in my near future.

Fi-Q · Feb 1, 2012

Did your 400 watt pure sine wave inverter handle the system prettu good ? If so, maybe you can find a small Utomatic transfer swith to putnon it, then your invert / battery / charger couple to tha automatic transfer switch would act exactly like a ups. As far as i know, most of the AC rotating motors & pumps don't like modified sine wave.

huffdawg · Feb 1, 2012

jebatty said:
I haven't seen this mentioned in any of the threads I've read on battery backup for boiler controls and circulators, so here goes. I changed my backup from a 400 watt modified sine wave inverter operating on a 12V battery, which require manual switchover, to an 800VA UPS computer style backup operating on 24 VDC (2 x 12 volt batteries in series) which automatically switches over. I changed out the internal batteries to 2 - 104ah gel cells.

The good news is that on a power failure the switchover went fine, boiler continued to operate and circulators continoued to run, although the circulators (15-58, 009 and 007) emitted an audible buzz. The Kill-o-watt reported 111VAC; our normal line voltage is 120-122AC, and a little less than 400VA.

The bad news is that the UPS modified sine wave would not cold start the 15-58. I tried to start the system on the UPS backup, and the boiler controls lit up, the 15-58 emitted a buzz, but there was no flow. Speed setting was M, I switched it back and forth a couple of times between M and HI, and then it started. As best as I could tell the 009 and 007 started up OK.

I'm guessing either that the UPS could not provide sufficient start up current, or that the 15-58 doesn't like modified sine wave much at all, or both. From what I have been able to find is that motors will run hotter under modified sine wave and may emit a buzz, which these circs definitely did, and that modified sine wave may not be good for some motors.

Anyone else experience a similar issue? Or can try a cold start on the UPS and see if they have an issue? A pure sine wave UPS may be in my near future.

This might not be related Elliot but I have a 15-58 thats on my inslab circuit . I operate it manually by plugging it into the outlet and sometimes it won't start on low speed . I have to jump start it by switching it to medium or high speed then back to low and then it works normally.Its a brand new circ too.

Huff

stee6043 · Feb 2, 2012

I have never tried this but now I think I want to. Perhaps I'll report back.

jebatty · Feb 2, 2012

Did your 400 watt pure sine wave inverter handle the system pretty good ?

It too is a modified sine wave inverter. I thought it handled the system fine, but now I don't know that either. I have pilot lights on my circs to know whether or not they are "on," but they really only indicate whether power is going to the circ, they don't actually show that the circ is operating. On my next burn I will test the 400 watt modified sine inverter.

The way I discovered that the circ was not operating, even though it had power, was that the boiler was in a high burn and I noticed that boiler temp was climbing rapidly while return temp was holding steady at 143F. At return temp of 143F supply temp normally would be about 163F. Boiler temp was up to 190F and the Tarm was moments away from high temp draft fan shut down and going into idle mode when I tried switching the speeds on the 15-58, which started it spinning. Boiler temp then fell quickly.

It's possible that this won't happen every time, and it's possible it won't happen at the HI speed setting, which is where I have the 15-58 now, rather than M. What concerns me is that I need to know that the 15-58, as well as the 007 and 009, will start every time. Backup power does little good if a circ won't start.

woodsmaster · Feb 2, 2012

The ciculators must start easier on high. In the manual it says if it has been sitting idel for a long period to start on high then switch
down.

SmokeEater · Feb 2, 2012

huffdawg said:
jebatty said:

I haven't seen this mentioned in any of the threads I've read on battery backup for boiler controls and circulators, so here goes. I changed my backup from a 400 watt modified sine wave inverter operating on a 12V battery, which require manual switchover, to an 800VA UPS computer style backup operating on 24 VDC (2 x 12 volt batteries in series) which automatically switches over. I changed out the internal batteries to 2 - 104ah gel cells.

The good news is that on a power failure the switchover went fine, boiler continued to operate and circulators continoued to run, although the circulators (15-58, 009 and 007) emitted an audible buzz. The Kill-o-watt reported 111VAC; our normal line voltage is 120-122AC, and a little less than 400VA.

The bad news is that the UPS modified sine wave would not cold start the 15-58. I tried to start the system on the UPS backup, and the boiler controls lit up, the 15-58 emitted a buzz, but there was no flow. Speed setting was M, I switched it back and forth a couple of times between M and HI, and then it started. As best as I could tell the 009 and 007 started up OK.

I'm guessing either that the UPS could not provide sufficient start up current, or that the 15-58 doesn't like modified sine wave much at all, or both. From what I have been able to find is that motors will run hotter under modified sine wave and may emit a buzz, which these circs definitely did, and that modified sine wave may not be good for some motors.

Anyone else experience a similar issue? Or can try a cold start on the UPS and see if they have an issue? A pure sine wave UPS may be in my near future.

Click to expand...

This might not be related Elliot but I have a 15-58 thats on my inslab circuit . I operate it manually by plugging it into the outlet and sometimes it won't start on low speed . I have to jump start it by switching it to medium or high speed then back to low and then it works normally.Its a brand new circ too.

Huff

Coincidence! I was just reading up on how to install and start the 15-58 and Grundfos even states that the 15-58 should initially be started on the hi speed setting and then if it doesn't start to remove the screw cap off the motor's shaft end and give it a turn with a bladed screwdriver. There's even an arrow to indicate the rotation direction.

jebatty · Feb 2, 2012

I guess you can tell that I did not read the 15-58 manual, but that gives me pause for concern. What is the value of a multi-speed circ if it cannot be relied upon to start except on High speed? And if through error or inadvertence in not starting on H and the circ is set on L or M and does not start, although power is supplied, what is the effect on the circ? A non-start could go on for a long time.

Any similar experience by anyone with a single speed Grundfos, Taco or other? Or a multi-speed of any other model or brand?

woodsmaster · Feb 2, 2012

You should only have to start it on high if it has been sitting idle for an extended period of time. Probably need the true
sine wave ? Not enough power to start it.

huffdawg · Feb 2, 2012

jebatty said:
I guess you can tell that I did not read the 15-58 manual, but that gives me pause for concern. What is the value of a multi-speed circ if it cannot be relied upon to start except on High speed? And if through error or inadvertence in not starting on H and the circ is set on L or M and does not start, although power is supplied, what is the effect on the circ? A non-start could go on for a long time.

Any similar experience by anyone with a single speed Grundfos, Taco or other? Or a multi-speed of any other model or brand?

I have 4 other 15-58's they have had no problems starting in low speed . Just the one that I unplug from the wall to start and stop

Fred61 · Feb 2, 2012

I know very little about the output power of inverters, however I made a quick decision to return the 750 watt modified sine wave I purchased within 30 minutes after installing it.
There are things I would rather be doing than troubleshooting controller and circulator problems.

My overheat circulator is controlled by an aquastat that I mounted in the spare well tapping on the top of my eko. When tripped, it circulates boiler water through a coil in placed in the bottom six inches of my 500 gallon upright stainless unpressurized tank.

Although the plan is to be able to run the entire system with the inverter, however I only have the back-up power hooked to the overheat circulator.
Since I only have one, three to four hour fire per day just to recharge my storage I don't feel that it needs to be hooked up to run the entire system. But I have the capability if needed. Just need to unplug a couple cords (electric kind) from one receptacle and plug them into the inverter.

The first time I plugged in the modified wave unit and tested the overheat circulator and heard the humming, visions of vibrating coils in the motor winding flashed through my head. I envisioned wear in the varnish coating which would eventually cause a short in the winding. I also surmised the the unit would run hotter.

I have the ecoster2 LED controller on my eko and the LED were blinking and fading when I tried to hook the inverter to the whole system since I wanted that option. Decided that a mod sine wave was not for me.

I went out and spent the big buck on an AIMS 1500 watt pure sine wave inverter with integral charger and automatic switchover and have slept like a baby ever since. I hook the unit up to three deep cycle batteries that come out of my motorhome each fall after I put it to bed. Since I store the RV several miles from here in a heated warehouse it gives me the opportunity to keep the batteries maintained right here in my basement.

Pat53 · Feb 2, 2012

I've got 15-58's and have never had a problem with them starting on low speed

dpsfireman · Feb 2, 2012

The manufacturers of inverters should not be allowed to call the output "Modified Sine Wave". The waveform they put out is closer to a square wave than a sine wave. I ended up building my own UPS using a sine wave inverter, battery tender/charger and a relay. I tried a modified sine wave unit and the blower on the Biomass would only run at if it was set to full speed due to the triac circuit used to control the speed. I wonder if the 15-58 uses something like this. Here is a schematic of what I built.

KenLockett · Feb 2, 2012

jebatty said:
I guess you can tell that I did not read the 15-58 manual, but that gives me pause for concern. What is the value of a multi-speed circ if it cannot be relied upon to start except on High speed? And if through error or inadvertence in not starting on H and the circ is set on L or M and does not start, although power is supplied, what is the effect on the circ? A non-start could go on for a long time.

Any similar experience by anyone with a single speed Grundfos, Taco or other? Or a multi-speed of any other model or brand?

Jim,

What kind of output duration do you expect to get with this UPS backup setup assuming your just operating the circulator and fan on the Tarm control panel? Are you using just deep cycle chargeable 12VDC batteries. Assuming so what size?

One of my next project was to be installation of generator to run boiler in times of loss of power but your idea is interesting,

Ken

huffdawg · Feb 3, 2012

dpsfireman said:
The manufacturers of inverters should not be allowed to call the output "Modified Sine Wave". The waveform they put out is closer to a square wave than a sine wave. I ended up building my own UPS using a sine wave inverter, battery tender/charger and a relay. I tried a modified sine wave unit and the blower on the Biomass would only run at if it was set to full speed due to the triac circuit used to control the speed. I wonder if the 15-58 uses something like this. Here is a schematic of what I built.

Would a pure sign wave inverter work

Huff

Fi-Q · Feb 3, 2012

[/quote]

Would a pure sign wave inverter work

Huff[/quote]

Pure sine wave is, or is pretty close to be the same exact sine wave that is usually provided by shore pwoer. So, they are the best to use. If sized correctlly, it should work no problem, and you should have no humming in motors or blanking on controllers if using a pure sine wave inverter.

SmokeEater · Feb 3, 2012

jebatty said:
I guess you can tell that I did not read the 15-58 manual, but that gives me pause for concern. What is the value of a multi-speed circ if it cannot be relied upon to start except on High speed? And if through error or inadvertence in not starting on H and the circ is set on L or M and does not start, although power is supplied, what is the effect on the circ? A non-start could go on for a long time.

Any similar experience by anyone with a single speed Grundfos, Taco or other? Or a multi-speed of any other model or brand?

Sorry, the manual does state the start-up procedure, but I forgot to mention that this is for initial start up only. Reason, I believe, is that the shaft is water lubed and that first turn with a possible dry shaft may need some coaxing. One the pump is wet, all's well and will normally start on any setting.

jebatty · Feb 3, 2012

What kind of output duration do you expect to get with this UPS backup setup assuming your just operating the circulator and fan on the Tarm control panel? Are you using just deep cycle chargeable 12VDC batteries. Assuming so what size?

My batteries are 2 x 12vdc at 104ah each, deep cycle gel cell type. With just the Tarm draft fan and controller plus the 15-58 on HI, draw is 200va, which is 200 / 24 = 8.33 amps. For longest battery life the recommendation is to not draw down the batteries below 50%. That means that operating time is 104 / 8.33 / 2 = 6.24 hours. In an emergency the batteries could be drawn down to cutoff and I would estimate another 3 or more hours, perhaps. With the entire system active, that is adding the 007 and 009, draw is 400va, so operating time would be 1/2, or 3.12 hours to 50% draw down.This should be plenty of time to cover an emergency power outage if I was not around to fire up the generator.

A lengthy power outage of multiple days would require more, and then I would use the backup generator. I have a 2000 watt pure sine wave inverter generator which is sufficient to power the entire system and recharge the batteries.

Would a pure sign wave inverter work

A pure sine wave inverter would be better, eliminate the buzzing, and everything should work just like it was on line current. But I think there may be an issue on circulator start up, which requires a lot more power than when operating. It would be important to test the backup system to make sure it works, regardless of the inverter.

Another Issue

I also tried another UPS inverter I had, which is old and was supposed to be a pure sine wave inverter. I don't have a scope so I don't know how clean the power is, but when I hooked it up to the system it powered everything and no circ buzzing, so it may be pure sine. But, on power loss, although it does switch automatically to backup power, the Tarm controller shuts down and has to be manually restarted. Maybe it doesn't switch fast enough and there is a brief power loss which shuts down the controller. If you go the UPS route it will be important to test your system under a variety of conditions to make sure the backup works as intended. Maybe someone has a fix for this shutdown. Might a capacitor (what size?) across the power terminals do it?

pwschiller · Feb 3, 2012

Jim,

I'm curious what make and model your UPS is? I have one that I am planning to use, which got me wondering whether it would work. It claims to produce a "sine wave": http://www.apc.com/resource/include/techspec_index.cfm?base_sku=SU700XL

The following page: http://www.pcguide.com/ref/power/ext/ups/funcOutput-c.html
shows square wave, "modified sine wave", and sine wave power curves superimposed on one another. This is what they have to say about "modified sine wave":

Modified square wave output is used on many lower- to middle-range UPSes, and is also sometimes called "stepped approximation to a sine wave", "pulse-width modified square wave", or even "modified sine wave". The last term is marketing cutesy-speak, since the output form isn't really a sine wave, modified or otherwise.

If that graph is a fairly accurate representation of your "modified sine wave", then I could see where electric motors might have problems with it.

jebatty · Feb 3, 2012

Iâ€™m curious what make and model your UPS is? I have one that I am planning to use, which got me wondering whether it would work. It claims to produce a â€œsine waveâ€

My old UPS probably pure sine wave is NCR 4072-1400-7194. I cannot locate a manual or specs for it. The UPS with modified sine wave that I'm using is APC XS800. If the UPS you plan on using was relatively inexpensive, it likely is not pure sine wave. Pure sine wave inverters are considerably more expensive that their modified sine wave counterparts.

pwschiller · Feb 3, 2012

jebatty said:
Iâ€™m curious what make and model your UPS is? I have one that I am planning to use, which got me wondering whether it would work. It claims to produce a â€œsine waveâ€

Click to expand...

My old UPS probably pure sine wave is NCR 4072-1400-7194. I cannot locate a manual or specs for it. The UPS with modified sine wave that I'm using is APC XS800. If the UPS you plan on using was relatively inexpensive, it likely is not pure sine wave. Pure sine wave inverters are considerably more expensive that their modified sine wave counterparts.

Mine was not inexpensive. The APC Smart-UPS 700XL that I have specifies "Waveform type = Sine wave" in the tech specs: http://www.apc.com/resource/include/techspec_index.cfm?base_sku=SU700XL

The APC Back-UPS XS 800VA has no mention of waveform type, crest factor, or even output frequency in the comparable tech specs page: http://www.apc.com/resource/include/techspec_index.cfm?base_sku=BX800&tab=models

jebatty · Feb 3, 2012

Cost may be a good indicator. Most UPS's that are pure sine wave clearly state "pure sine wave." If you have access to a scope, you can check it out. Also if when you use it you do not notice any buzzing from a circ, that would help. Further you could try it on a fluorescent bulb, which may tend to flicker if not pure sine wave.

DaveBP · Feb 3, 2012

I'm just speculating here but I would also suspect that those output graphs for the various waveforms are given across a purely resistive load. Inductive loads (motors, transformers, about anything with a coil) are going to "twist" the waveform to some extent. How the inverter electronics deals with a motor winding under load could also vary from model to model. And again, the more expensive ones are probably going to perform better.

Just one more variable to the answer of whether any particular inverter system will drive your system.

Putting a capacitor across an inverter AC output will "twist" the power the opposite direction from a motor. I don't think it will do you any favors. A larger filter cap in the power supply on an electronic system may allow it to carry the circuits longer before they drop out but as far as the Tarm goes it may only be one of the relays in there that lets go without power for that tiny interval.

It's that switching relay and how long the inverter circuitry can power up that will determine whether any given electronic load will make the hop without dropping out. My current UPS switches in 4 milliseconds (according to the spec sheet) but I seem to remember that my long ago model was 20 or 30 ms. Big difference.

dpsfireman · Feb 3, 2012

That circuit I used may be trouble with some units because the switching time is relatively long due to the mechanical relay. My Biomass doesn't care and will remember what it was doing with no problems even if the power is interrupted for much longer. A real UPS would switch much more quickly (like DaveBP's unit) and should work with anything.

Fred61 · Feb 3, 2012

I think if you measure the output with a simple hand held meter with no other load a pure sine wave will read 120 volts. A modified sine wave or a square wave would measure 80 to 90 volts. Try it and see what you get for a reading.

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