Power Factor Correction (KVAR) At Sugarhouse

[Tmeeeh]

We are nearing the electrical load limit at our sugarhouse. The Sugarhouse is 1,100 feet of #2 ought aluminum wire from the transformer. With all motors and lights running we are seeing 218 volts at the Sugarhouse and 240 at the supply. (A 22 volt drop)

I'm considering installing the K-1200-R at this site http://www.lakes-list.com/Original%20KVAR%20SYSTEM.htm?gclid=CL6-l87qlKUCFQRM5QodlWBcNAThe sales person there assures me we will have up to 20% more power available at the Sugarhouse panel.

Does anyone here have experience with this sort of thing?

[Dennis H.]

Looks like something that I may need to look into!

[tuckermtn]

Tim- try PM-ing powerdub on the site here (go to member list and find him there)

he is my go to guy with electrical questions...

[maplwrks]

How much does this piece of equipment cost? I would think if you just upgraded your service, (heavier wire and bigger transformer) you could achieve the same results.

Looking at your profile, you must be getting close to maxing out the service you currently have. I would assume that you have a 100 amp service. You should be running a 200 amp minimum.

[Tmeeeh]

If I understand power factor correction right, you can gain up to 20% capacity on the sub panel at the sugarhouse. If the power factor is .8 (bad) and it is adjusted to 1(perfect) you gain 20% capacity. Correction involves installing capacitors in a box near the sub panel.

In commercial applications a someone comes to your site, hooks up a power factor meter and adds capacitors until the power factor is good.

The guy I talked to who sells whole house power factor correctors said don't go to the trouble and expense of having someone come out. Just buy my unit for $149.00 and you'll be happy. (much less costly then new wire and service)

Thanks Eric, I will do more research on this and post here what I find out..it may take a while.

On another note Brad from Leader is coming here this morning to test fire our new complete evaporator. It's the first they have made that size. Supposedly will evaporate up to 190 GPH

[twofer]

Let me preface this by saying I'm not an electrician.

Your wire size seems to be undersized by a good margin. We are currently putting in a 100 amp 370 foot line from my homes main panel to the sugarhouse. Using an acceptable voltage drop of 3% the wire gauge for aluminum comes out to be 350 MCM.

Here is the calculator I used when I sized my wire: http://www.southwire.com/ProductCatalog/voltdrop.jsp

[maplwrks]

I agree---sounds like a huge bandaid to me

[DrTimPerkins]

If I understand power factor correction right, you can gain up to 20% capacity on the sub panel at the sugarhouse. If the power factor is .8 (bad) and it is adjusted to 1(perfect) you gain 20% capacity. Correction involves installing capacitors in a box near the sub panel.

I'm not an electrician either, but I do a lot of electrical work in the lab and field. A capacitor basically acts like a short-term, in-line battery. It stores energy (from the line) and provides it -- when needed -- in a short-term burst (lasting a few seconds to few minutes depending upon the design and size). If that is what this device consists of, it seems like it might be potentially useful for providing a little extra boost for starting-loads, so it might help get you "over the hump" when you turn on your pump or RO. However if you're operating close to the load limit, I can't see how this could possible increase the running load capacity at all (it's another of those pesky "laws of physics" things...in this case, the first law of thermodynamics, "energy can be neither created nor destroyed, only transformed") unless it were enormous (house-sized). If you need more running load amps, the only recourse is to increase the service (bigger transformer, bigger wire = more amps to the sugarhouse). It is often not good to run large devices underpowered....really bad things can happen that can ruin your day and your wallet.

Power Factor Correction CAN help in large industrial settings with lots of inductive loads that shift/distort the power signal. I've not heard of it being used in smaller settings much.

[jasonl6]

I use to install allot of car audio systems back in the day. The big thing was to add capacitors to help with the amplified draw. However once the capacitor has depleted it's energy it too acts as a draw. Basicly an underpowered system now has to creat even more power to charge the capacitor too.

I know the above is in a 12v setting but it's the same principles.

Jason

[Mark]

Go with a larger wire instead of that unit, it sounds a little too good to be true.
When you run a bunch of induction motors you can push the amps and volts slightly out of phase. The watt hour meter will not read all of the power used when the amps and volts don't peak at the same time and that is why they charge a penalty on the larger offenders.

[Dennis H.]

Remeber that Power factor correction works best with the correction being done at the inductive load.
If you place the Power factor correction at a panel and then have a distance of wire you will gain nothing. Since the wire it self has resistance the wire will basically cancel out any benifits.

I may be wrong with this and I usally am, but how can a power factor correction help in undersize wire. Power factor correction is used to correction the phase shift caused by the inductive load(motor). What you are saying is that you are losing 20V because of the long run and too small of conductor.

[Tweegs]

Think of it as water running through 5/16ths. No matter how much pressure you have available at the source, you’ll only get X amount at the other end. Now if you were to fill a bucket (capacitor), and then drain it with a load/motor start up, you still haven’t increased the flow through that 5/16ths, which is what you need.

Increasing the size of that 5/16ths is the only way to go to get more juice where you need it.

[tuckermtn]

replacing the wire to the sugarhouse I would guess is going to be pretty expensive- its probably in excess of 1000ft (in underground conduit) from the house to the sugarhouse at tmeeh's place. beautiful spot...

[Beweller]

First, notice that phrase "up to 20 percent". That includes zero.

The bucket analogy is incorrect. Power factor correction capacitors do not store energy for seconds or minutes. If you try to look at energy storage and release, it occurs for fractions of a cycle.

If your power factor is poor, power factor correction at the load will reduce the line current draw. Notice the occasional use of the term "wattless current" to describe low power factors. Poor power factors usually result from inductive loads which are usually motors. Resistive heating and incandescent lamp loads have near unity power factor. Fluorescent lamps may have poor power factors but are not usually a significant factor (except shopping malls!)

[firetech]

First, notice that phrase "up to 20 percent". That includes zero.

The bucket analogy is incorrect. Power factor correction capacitors do not store energy for seconds or minutes. If you try to look at energy storage and release, it occurs for fractions of a cycle.

If your power factor is poor, power factor correction at the load will reduce the line current draw. Notice the occasional use of the term "wattless current" to describe low power factors. Poor power factors usually result from inductive loads which are usually motors. Resistive heating and incandescent lamp loads have near unity power factor. Fluorescent lamps may have poor power factors but are not usually a significant factor (except shopping malls!)

I'm having an issue getting to post this where it needs to be but heres is my 2 cents worth. Your problem in not an out of phase shift (power factor). There is no way a sugar house can have a power factor problem. This is mostly related to ballasted loades (flouescent lighting and mass use of computers). Your issue is simply voltage drop due to the lenght of run and wire size. If it were my problem I would be looking at a transformor to boost my power to the level of voltage that my motors need at the point of utilation. Your wire installed is most likley 600v rated that means you can apply volages to 600v. Back to the electical pie higher voltage less amps. Ampereage is the limiting factor to wire installations. Boost the volage reduce the amps to the rating of the wire. Most transformor are multi tap meaning that you can get many voltage from them they are designed to fix problems like yours. Boost to 480v use the existing wire and transform back to 120/240 at the sugarhouse. 2 transformors installed a couple of disconnects and no new wire. My thoughts thanks for reading

[maplwrks]

Every one that has chimed in here is correct. There are only 2 solutions to this problem, 1, Increase the size of your service. 2, Go to a 480v service and put a transformer at the sugarhouse to drop it back to 240v.

[Tmeeeh]

Thanks all for the info on this. After talking to three motor repair shops and three electricians who specialize in electric motor controls, variable frequency drives and transformers. They all agree that motors are designed to run within 10% under or over their nameplate rating. They also all agree it's best to stay within 5% of the nameplate rating. After the voltage drop in the wire to the sugar house, we have 218 volts with all the motors and lights running. This is about 5% under the nameplate rating. They say to watch the voltage and as long as we stay over 218 volts at the motors the motors should be fine. They also suggest using a clip on ammeter to see that the amperage stays within the same 5% of the nameplate rating. Also start one motor at a time.

The damage done by running on low voltage is premature winding wire insulation breakdown and shorting out and possible fire. Most common damage is motors that can't start because of low voltage yet keep trying to go until they burn out.

They say forget about power factor correction and use transformers or run an additional wire or replace the existing one. I'm going to get quotes on using transformers.

[Beweller]

Notice that if you did correct the power factor from 0.8 to 1.0 you would still have something like an 18 volt drop. That is rather large.

Going to 480 volts on the line will reduce the current to half--depending on how the load responds to the increased voltage. That will reduce the drop to 11 volts. Still rather large.

I would guess the two transformer approach would be more expensive than increasing the wire size, but that may depend on how difficult it may be to do the replacement.

[Thad Blaisdell]

I have been reading all of these posts and my thought would be to run a new service, but keep it overhead most of the way. 1100 ft underground that is a bit much for the amount of power you will be using. Let alone how hot the wire must be getting when you are close to full load. Go overhead for most of the way then go underground the final 100-150 feet. The transformer would be on the pole closest to the sugarhouse and you would be all set. No matter what you do it will be pricey.

[maple flats]

You need more info before this can be answered. What is the amperage at full load? Do not use the name plate amps, but start all but the biggest motor and let them run a few seconds, then turn on the biggest motor and get the spike load amps. With that asnwer, I can calculate what you need to do.
The KVAR or similar will not correct the problem. the transformers would but might cost far more than you are willing to spend, get prices. You will need to know amps for that too. Also, check the input voltage over a period of time. Input is not static. You must be ready for the lowest input voltage and your needed amperage. To get amps you need a clamp on ampmeter and must seperate the wires to read each hot line individually. I will check in to see if you get the amps posted so I can calculate this. You most likely have 2 choises, the transformer idea or change the wire. While much more costly, 2/0 copper will handle the 195 amps max, while 3/0 alum is 175 amp max and 4/0 alum is 205 amp max. When I get the amps you are using I will multiply
(amps x feet) / (acceptable V drop x voltage). This will give me a VDI (voltage drop index) and I have a chart to chose the right gauge. You do not want either leg to ever drop below 110 or 220 for both. If it does you will shorten the motor's life. Also, if line resistance is dropping V more than that, you are heating the wire, which adds more resistance and drops it further with time. The wire inside the conduit could conceivably fail in the middle of the season because of heat buildup inside the conduit. You will notice that the utilities keep the lines seperated to allow cooling, until they leave the transmission lines to go to your service entrance box. The distance complicates this as I am sure you realize.

[maple flats]

The max load amps I showed above are not what you will likely be running, it is just a number that you can not exceed even if all other calculation say you can use a given gauge wire, you must still not exceed the max amp number at any time, even at starting surge amps.

[Tmeeeh]

Dave,
Adding up the nameplate amperage comes to 68 Amps. I can't run the RO machine now because It is taken apart for winter storage. I can't tell you the starting surge. It is the biggest load in the sugar house with a 7.5 hp and 3 hp motors. They don't start at the same time. Last year the voltage with everything running was 220 usually we are supplied with 242 to 245 at the service entrance.

I do monitor both voltage and amperage at the sugar house panel during the season and make sure L1 and L2 voltages are balanced.

This year the load will be a little more because I took out two 1/2 hp blowers and replaced them with a 1/3, 1/5 and 1 hp blowers.

The online voltage drop calculators tell me the voltage with the new load will be 118 to 220.

Electricians and motor repair shops tell me it's OK to run 230 volt rated motors within 5% of the nameplate rating. That means 118 volts is OK. I'm not sure though.http://mapletrader.com/community/images/smilies/confused.gif

Two transformers would probably be too costly. I could run a second wire to carry some of the load.

[poolguy]

ive seen some 15 kva 480/220 transformers with taps on ebay for around 350 bucks.......we got ours for 165 ea. now dont quote me on this as im not an electrician by NO MEANS. but i think what my electrician did was bumped the 240 from my parents house up to 480.....and then i think what the taps do is bump it up just a bit more to compensate for the drop on the way back to the sugar shack.....not all but some. then at the shack we have another transformer ....again with taps (not all of them have taps) and dropped it back down to 240 and then adjusted those taps up to further compensate for the loss due to the distance. now...again...according to him we have acceptable power. the proof is not yet there for me as we are currently switching things over from gas generator and gas vac pumps to all electric.....ill say it worked for sure when i see it all run lol. and heres the real clincher.......ITS 3100FT TO THE SHACK. the wire we used was from a developer that used it to run 7200 line voltage throughout developments and with the economy he has now retired and gave it to us for a song. again im no electrician but even with the massive size of the wire it would not work without transformers WITH TAPS to get good power that far. hope it helps and dont come down on me to hard if i didnt get all this right cuz when i walk down the road people point and say "hey there goes dave the pool guy" not "there goes dave the electrician" :lol: good luck and ill let you know if mine works when its all hooked up.

[Amber Gold]

Tim, How many amps does your new evaporator use?

[Tmeeeh]

My new 3X10 Evaporator has three blowers. The low pressure blower for air under the grates is 1/5 hp 3.9 Amps@115v, the high pressure blower for the secondary air in the firebox is 1/3 hp 4.8 Amps@115v, and the steam away blower is 1 hp 6 Amps@230v. I will be drawing about 4.5 Amps@230v more than last year.

I think I will be OK as long as the power company continues to provide 240 to 243 volts. After the voltage drop in the feed wire to the sugar house the voltage there should be 219-220. I called the motor manufacturers and they say their motors are OK to run within 10% of the nameplate rating. As low as 208 volts. It looks like I will be about 5% below the nameplate rating. I just got a wall mounted volt meter on ebay from China for $9.95. I can watch the voltage and if the power company supply voltage gets low (brownout) because of a storm or something, and I see the sugar house voltage go below say 215 I can start shutting down electric loads.
See a recent article on us at: http://www.concordmonitor.com/article/225386/upgraded-maple

[Brokermike]

great article, they ought to shut down the comment section though. We have the same problem with our local paper. No matter how nice a story they publish there's always vultures circling in the comment section.

[Amber Gold]

Good article Tim. Did you make 1100 gallons last year on 1850 taps, or is 1100 gal a typical year? Is the article correct that you have a 1,000 acre farm? How many acres of maples do you tap and do you have plans for expansion?

[Tmeeeh]

Last year we made 1,100 gallons of syrup. Not quite .6 gallons of syrup per tap. That is our highest pet tap yield yet. 150 gallons of that was commercial grade. Possibly a result of sap running later in the season due to check valve adapters. We've been actively managing our maple woods (thinning) since 1974, we keep our tubing lines short and steep, one tap per tree unless the tree is nearly three feet diameter, we find and fix vacuum leaks daily, use check valve adapters and tap almost exclusively sugar maples.

My folks bought this place (1,000 acres) in1950 My brother and my wife and I own it now. We already tap nearly all the available sugar maple trees on our land. There are more but they are scattered and hard to access. One sugar bush has 750 taps on I'm guessing 9 acres and the other is 1,100 taps on about 50 acres. The actual sugar maples are more scattered and grouped in stands within the 50 acres. There is lots of pipeline in that sugar bush. We don't plan on major expansion. Mostly we go for high per tap yields on the trees we have. We try to be as efficient as we can be in the sugar house to minimize the time spent there. Sap comes from the trees so we spend plenty time during the season and off season with them.

[Tmeeeh]

Just to update this thread. We have had some sap to RO and boil and a wall mounted volt meter to monitor voltage. With all electric loads on the lowest voltage I've seen is 225. That's a 20 volt drop in the wire to the sugar house That's better than I hoped for. It's nice to be able to monitor voltage because if the power company starts sending lower voltage ( below 230) I'll see on the meter at the sugar house that it's time to reduce loads or risk damaging motors. The motors are rated to be OK down to 208 but it would probably be better to stay above 220.

[Flat Lander Sugaring]

A rule of thumb is 10% + OR -. I want to say the highest VD you want to see in a run is 5% for the wire and equipment
"Electrical equipment is designed to operate at within a given voltage range, typically no less than 10% and no more than 5% from it’s voltage rating.

Example: A typical 230 volt load is designed to operate at not less than 207 volts (-10%) and not more than 242 volts (+5%)"


VD = 2 x K x I x D/CM

“VD” = Volts Dropped: The voltage drop of the circuit conductors as expressed in volts.

“K” = Direct Current Constant: This is a constant that represents the direct current resistance for a one thousand circular mils conductor that is one thousand feet long, at an operating temperature of 75º C. The direct current constant value to be used for copper is 12.9 ohms and 21.2 ohms is used for aluminum conductors. The “K” constant is suitable for alternating current circuits, where the conductors do not exceed No. 1/0.

“Q” = Alternating Current Adjustment Factor: Alternating current circuits No. 2/0 and larger must be adjusted for the effects of self-induction (skin effect). The "Q" adjustment factor is determined by dividing alternating current resistance as listed in NEC Chapter 9, Table 9, by the direct current resistance as listed in Chapter 9, Table 8.

“I” = Amperes: The load in amperes at 100 percent, not 125 percent for motors or continuous loads.

“D” = Distance: The distance the load is located from the power supply, not the total length of the circuit conductors.

“CM” = Circular-Mils: The circular mils of the circuit conductor as listed in Chapter 9, Table 8.
I'll get you some other calcs you might find useful

[green4310]

The theory behind this looks to be sound. You can never aciieve a Pf = 1 but you may be able to gain enough to avoid a complete redo of your power line. As you lower your Pf by addind capacity, the line amps will fall. This will mean less voltage dropped across the power line and more volts available to your sugar house. They say you can try it for a time to see if you like it. Just connect an Ammeter in your main line or use a clamp on, and watch it, just like the demo. If it is going to work your amps will go down.