Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-07-2011, 10:16 AM   #31
Member
 
Join Date: Jan 2011
Posts: 43
Share |
Default

dimming lights from large geothermal heat pump


Quote:
Originally Posted by AndrewF View Post
I have 400 amp service (split to two 200 amp panels)

The utility put in 4/0 cabling IIRC.

I have a 5 ton HP and when it kicks into defrost with the 20KW backup heat kicking in, the lights on its subpanel in the basement dim briefly. (It is annoying) but anything else in the house which ties into one of the two 200 amp panels are fine.

The basement panel is a 100 amp sub panel fed by 2/0 copper.

We do experience a brief dimming when the HP compressor engages, I was told I could install a start capcitor that should be able to provide the in-rush current the compressor needs on startup....reducing the dimming issue, and theoretically extending the life of the compressor.

When I upgraded to 400 amp service, I questioned the poco engineer about the size of cable ran to the meter and even posted on here (would have to find the post) and was told, since they dont have to abide by NEC rules, they can use whatever they want.

The highest amp pull I have seen on the monitoring system I have, was around 210 amps.

This was with the ovens going, microwave, tvs, lights, water heater, Heat pump, backup heat and hot tub running. (holiday with family over)
Do you have any problems with bulbs burning out frequently or electronic equipment going bad more frequently than anyone else you know? Maybe i'm just the unluckiest guy ever for the past couple years on this, but it seems to be more of a pattern to me.

At my previous house (it was much smaller and had gas heat and water heater), I used the same bulbs I do now and never had one burn out in the 3 years I was there. I never had any electronics die when I was there.

I've been in my current house for a bit over 2 years now. It was all incandescent bulbs when we moved in and they burned out frequently, so I replaced every bulb in the house with new using the same (GE reveal) incandescent bulbs I've used at my old house (and for the past 10+ years). It may have helped some, but I still burn out a bulb or two a month.

My current place had a couple CFL's in the garage in those white single socket utility lights. They both burned out fairly quickly and I replaced them with some old 8' florescent fixtures that I pulled out of the barn.

I've even tried using some CFLs and LED bulbs and am having even worse luck with those.
- The GE reveal CFLs are lucky to last more than a month.
- The BrightEffects bulbs are about the same.
- The LED was something from Sam's club that I cant remember and may have been a bulb quality as lots of people complained on the net about those, but it only lasted a few weeks before it started dropping LEDs.
- I've recently put some GE dimmable CFLs in my kitchen recessed and lost one out of 12 so far there.
- I've also tried some more expensive CFLs using the OttLite HD bulbs. They seem to be lasting longer, but still no where near their life expectancy. But at $10+ per bulb, a bit steep.

I even replaced several can lights in my living room that were not properly IC rated though were buried in insulation, but not really any difference. I did go from 3 can lights + 2 fans with light kits to 6 can lights and no lights on my fans when I did this as well. These currently have GE Reveal incandescent bulbs in them and are the ones that I am primarily annoyed by. Maye just because they are in my living room where I spend most of my time. I do see the dimming else where, but since the heat pump kicks on in different stages, I have not been in a different room when it kicks on directly to high.

The CFLs dont suffer from the dimming, but I'm guessing the effect is taking its toll on the electronics in the CFL.


As for electronics, everything was on good (not cheapo models) surge protectors, etc.
- I've gone through a couple HP printers. My current Brother printer is so far so good.
- I've had two linksys routers die on me.
- My motorola cable modem (from time warner) burned out months apart from the linksys routers. The coax line was on a surge protector as well.
- My old TV was a mitsubishi 73" DLP (WD73831 and I've gone through 6 bulbs in 2 years and 2 light engines on it). It had a battery backup on it to help with any damage power outages would cause, so that was not a contributing factor.
- I just in October replaced that TV with an upgraded model from mitsubishi (WD73838) at mitsubishi's expense since they thought I had a lemon in the old TV. Just today it is failing to power on and I am waiting for a new bulb from mitsubishi.
- A processing board in my server (IBM x445) burned out and had to be replaced
- DirecTV DVR (HR-21) died and needed to be replaced.
- my diswasher (1 year old Samsung) is also acting up and the repair tech is due out today to look at it.
- the original fridge that came with the house (whirlpool something or other) burned out a starter relay or something (cant remember what it was now). I've replaced this with a samsung model as well now.

My old downstairs air source heat pump (Carrier SS Tech 2000) also had a problem the year we moved in. I didnt ask what it was since my home warranty covered it. The upstairs one had a problem with the start relay this past year and then the air handler burned out. The old heat pumps were older though the HVAC guys I had looking at them expected them not to be having so many problems. I replaced them with my current geothermal heat pump due to these problems and the fact they were undersized for my house (previous owners convered patio to sunroom) and costing me $5-600 per month during the hottest and coldest months.

atuel is offline   Reply With Quote
Old 01-07-2011, 11:26 AM   #32
Member
 
Join Date: Jan 2011
Posts: 43
Default

dimming lights from large geothermal heat pump


Quote:
Originally Posted by chiefWright View Post
I think someone needs to be monitoring minimum voltage in the house at the loadcenter in addition to what the POCO is doing out at the meter to make sure you don't have an internal wiring problem. It doesn't need to be all the time, just get minimums when the heatpump turns on.

The more I think about it, if you've got a weak cable connection at the loadcenter, you want that known and fixed right away!
I'm looking into finding someone down here to bring in the monitoring gear. So far the electricians I've had out on other issues have been crap with me having to tell them they are screwing up (and i'm just an engineer - not a license electrician). Those guys came recommended and were licensed/insured... so i'm back to the "yellow pages" to find a new guy.

I did have one guy check all the connections in the load center were tight after we did find a loose connection on one of the breakers feeding my exterior outlets. However, he did this without an actual torque wrench. Is that normal or should we actually be breaking out the torque wrench to check these? Should both both service mains and the individual circuit lines at each breaker be torqued to a certain specification? At the time, I wasnt aware of the high torque requirements for the mains... if it wasnt live, I'd just get my torque wrench and check quick, but dont want to do that while its live.

Would there be any visual evidence of a loose connection that I would be able to see? I did not see anything when I looked to indicate arc burns, etc. There is a little discoloration on the uninsulated main neutral but it may just be the compound they put on to prevent oxidation on the aluminium.
atuel is offline   Reply With Quote
Old 01-07-2011, 12:14 PM   #33
Licensed Electrical Cont.
 
Speedy Petey's Avatar
 
Join Date: Feb 2004
Location: NY State
Posts: 6,801
Default

dimming lights from large geothermal heat pump


Quote:
Originally Posted by atuel View Post
At the time, I wasnt aware of the high torque requirements for the mains... if it wasnt live, I'd just get my torque wrench and check quick, but dont want to do that while its live.
Not at all true.
You'd be surprised at just how low the torque values are for these terminations.
I was very surprised when I first started using a torque wrench at how much I was over tightening panel and meter terminations.

For residential work most "real" electricians have a feel for it. I have a 3/8" torque wrench and use it from time to time just to keep myself sharp as to what the actual torque should be.
Speedy Petey is offline   Reply With Quote
Old 01-07-2011, 12:18 PM   #34
Member
 
Join Date: Jan 2011
Posts: 43
Default

dimming lights from large geothermal heat pump


Quote:
Originally Posted by Speedy Petey View Post
Not at all true.
You'd be surprised at just how low the torque values are for these terminations.
I was very surprised when I first started using a torque wrench at how much I was over tightening panel and meter terminations.

For residential work most "real" electricians have a feel for it. I have a 3/8" torque wrench and use it from time to time just to keep myself sharp as to what the actual torque should be.
Sorry, high torque values was relative to the tool being used... my understanding its is only like 20 or so ft lbs for things like mains, but that is somewhat high to easily do with a short wrench or a screw/socket driver. Its pretty well nothing on a torque wrench or any longer wrench.

I didnt mean high as in torquing my axle nuts to almost 200ft lbs where you're giving it damn near all you got.

Last edited by atuel; 01-07-2011 at 12:20 PM.
atuel is offline   Reply With Quote
The Following User Says Thank You to atuel For This Useful Post:
Speedy Petey (01-07-2011)
Old 01-07-2011, 06:21 PM   #35
Member
 
Join Date: Jan 2011
Posts: 43
Default

dimming lights from large geothermal heat pump


So got a WTF question here...

I just went out to double check the tightness on the breaker terminations at the breaker at least. Saw my multimeter while I was grabbing a screw driver and through what the heck... i'll just check the voltage while I'm looking.

So checked the voltage and it read about what it should... I cant really vouch for the accuracy of my multi meter (its a craftsman model 82026 digital multi meter circca the late 90s). It was reading about 123-124 on phase to ground at both panels (makes me wonder if that is accurate a drop to 116-117 that the poco measured is actually an issue). I forgot what the exact numbers for the phase to phase, but I recall thinking nothing hugely out of the ordinary there.

Then I checked the terminations of the 4 awg cable for the heat pump at the load center. They were loose and a few strands of the THHN at the back of the neutral were not actually in the neutral bar. It was very hard to see... almost missed it except I dropped my screwdriver and happened to look up at a very sharp angle at it from below. My load center neutral holes are pretty much exactly 4 awg with no room to spare so guessing it was forced in and bent those back. They were bent perpendicular to the cable up against the side of the neutral bar. I re-terminated this including cutting the fowled end off and staring a new.

Also torqued the connections at both the neutral bar (which was actually pretty tight to begin with) and at the breaker. The breaker connections seemed loose though. I sort of noticed that ever time I torqued down the cable, the stranded THHN distorted a little bit and each time the cable was "wiggled", it got a little loose. The 70A breaker is supposed to handle 2 awg directly so the "clamp" so it was crushing the stranded THHN flat and any movement of the cable lets the strands move and then it needs to be tightened again.

So now the WTF moment. After doing all that and with the 70A breaker still off, I checked voltage again. It was doubled from my previous readings. Phase to Phase to phase was over 400 and phase to neutral was over 200 in both panels. My house isnt burning down here, so not sure what just happened. Even pulled the entire breaker for the heat pump out of the load center to break any circuit there, but still reads double what it should. So did my multimeter just die or is there something that would cause this?
atuel is offline   Reply With Quote
Old 01-07-2011, 06:51 PM   #36
Master Electrician
 
Join Date: Mar 2010
Location: Indiana
Posts: 2,831
Default

dimming lights from large geothermal heat pump


Get some new batteries for your meter.
brric is offline   Reply With Quote
The Following User Says Thank You to brric For This Useful Post:
Speedy Petey (01-07-2011)
Old 01-07-2011, 07:07 PM   #37
Electrical Contractor
 
jbfan's Avatar
 
Join Date: Jun 2004
Location: Newnan GA
Posts: 5,741
Default

dimming lights from large geothermal heat pump


Quote:
Originally Posted by brric View Post
get some new batteries for your meter.
x2 .....
__________________
Yes I am a Pirate, 200 years too late. "Jimmy Buffett"
jbfan is offline   Reply With Quote
The Following User Says Thank You to jbfan For This Useful Post:
Speedy Petey (01-07-2011)
Old 01-07-2011, 08:07 PM   #38
Member
 
Join Date: Jan 2011
Posts: 43
Default

dimming lights from large geothermal heat pump


I went and checked it about 30 minutes ago and it had dropped back down, though seemed like it was trending to increase a few volts every minute. It started at 123 or so and went up slowly to 129 in the space of a few minutes before I quit looking at it.

However, the meter has a low battery indicator on it. I just turned it on to check again and the battery indicator came on came on a minute later.

Changed out the battery and just checked again... With the same whatever load is running (at a steady state... no heat pump coming on), its just under 124V for each P2N and 246V P2P. Both are holding steady.

How accurate are these multimeters on voltage? Its a digital model that reads in tenths of a volt for up to 200V and in full volts up to 500V. At a glance, its not exactly a cheap walmart one, but not sure how good it is either. Are even the fairly cheap ones pretty accurate on reading voltage?

Basically, I'm wondering how much we can compare these readings to the first set the poco took with the PMI recording meter. They said lowest drop they saw was 116V in the first measurement they did where the heat pump wasnt running but in our conversations we assumed normal current was 120V. I didnt ask him what the voltage was before the drop occurred.
atuel is offline   Reply With Quote
Old 01-07-2011, 08:59 PM   #39
Newbie
 
Join Date: Jan 2011
Posts: 3
Default

dimming lights from large geothermal heat pump


In all likelyhood the poco is using a true RMS DVM and yours is not. That could explain the 10V difference. But not the 200V difrerence.

Low batteries causing a 2x swing in the AC measurement seems really unlikely. You might try putting the old batteries back in and see if you get 200V line to neutral. If not, then I'd be inclined to believe that 200V reading. If the poco is really giving you that much jump in your voltage, no wonder you've been burning thru appliances like cheap candles!

Do you really have a #4 coming back from the heat pump to neutral??? Most 220V heat pumps (and 220V appliances in general) don't have a neutral, just L1, L2 and ground. And if they do, it's frequently one wire size down.

If you've got three #4's coming back from the heatpump, could it be that one of the lines & neutral have been reversed? As long as neutral and the ground aren't connected at the heatpump (and they shouldn't be) you wouldn't get a short circuit, but it could seriously mess up the heatpump, and maybe explain why it's bringing down the rest of the house on startup!

Given all your trials, maybe you are just unlucky, but I doubt it. I feel for you!

Good luck, and be safe!!
chiefWright is offline   Reply With Quote
Old 01-07-2011, 10:03 PM   #40
Member
 
Join Date: Jan 2011
Posts: 43
Default

dimming lights from large geothermal heat pump


Quote:
Originally Posted by chiefWright View Post
In all likelyhood the poco is using a true RMS DVM and yours is not. That could explain the 10V difference. But not the 200V difrerence.

Low batteries causing a 2x swing in the AC measurement seems really unlikely. You might try putting the old batteries back in and see if you get 200V line to neutral. If not, then I'd be inclined to believe that 200V reading. If the poco is really giving you that much jump in your voltage, no wonder you've been burning thru appliances like cheap candles!

Do you really have a #4 coming back from the heat pump to neutral??? Most 220V heat pumps (and 220V appliances in general) don't have a neutral, just L1, L2 and ground. And if they do, it's frequently one wire size down.

If you've got three #4's coming back from the heatpump, could it be that one of the lines & neutral have been reversed? As long as neutral and the ground aren't connected at the heatpump (and they shouldn't be) you wouldn't get a short circuit, but it could seriously mess up the heatpump, and maybe explain why it's bringing down the rest of the house on startup!

Given all your trials, maybe you are just unlucky, but I doubt it. I feel for you!

Good luck, and be safe!!
The "neutral" I referred to is actually the ground. I misspoke. There are 3 THHN lines in a water tight conduit.. all are black insulated though one is marked with a piece of elec. tape. I confused myself since its not the typical bare ground when I was thinking before. Probable also means the re-termination I did will only help in the case the heat pump shorts out and needs the ground.

The only 220V with neutral I have is my new dryer upstairs that is a 10-3 with ground and 4 prong outlet. Old dryer outlet is the 3 prong setup.

Anyway, I'll keep monitoring here every so often and see what happens. Hopefully poco caught that as well since the monitor they're using it out there now.

I assume the only way to get that much voltage would be from a bad transformer? Or maybe somehow pushing too many phases down the wire somehow?

Found the manual for my multimeter... doesnt say true RMS anywhere, but has a specifications page saying voltage measurement has an accuracy of 1.2% with a 10 digit accuracy of the analog to digital converter.


BTW, I've been considering putting a full branch monitoring setup in place sort of like I have in my data centers so I can go back and review when my bill comes up too high or we have lame problems like detailed in this thread. Maybe even have it send me email to tell me to turn the damn lights off or something. I have not found one with the features I'm looking for at a price that I'm willing to pay for it yet though. The branch monitoring solutions are getting better and cheaper with the push for green everything.

In the mean time, I'd consider purchasing a better multimeter that would measure true values of current, power, and voltage. Maybe one with a recording history or at minimum a min/max/average over time and an ability to monitor both legs at once. I've been lightly looking for a while now, but if anyone has a suggestion on a certain meter, I'd appreciate it.
atuel is offline   Reply With Quote
Old 01-07-2011, 10:27 PM   #41
liscenced electrician
 
Join Date: Jul 2008
Location: Oregon coast
Posts: 983
Default

dimming lights from large geothermal heat pump


i read someone else suggest this and you blew it off, but i feel this is very important. Find out if your neighbor (that is being fed off the same transformer) is having the same lighting issues. If so, the problem may be too small of transformer.

i think you finally got over this part, but the nec does not apply to the power company. They ALWAYS use much smaller wires. I think on my house i have 4/0 aluminum on my side being fed by 1/0 on their side. Free air conductors just don't get as hot. There is very little air circulation inside a conduit and tons of air flow when its free air.

As others have said, there may be no "issue" to fix. The pump in question just might take ridiculous amounts of power to get moving. Im no pump or motor expert, but maybe their is something that can be done to lessen the current draw. Some sort of soft start.
jimmy21 is online now   Reply With Quote
Old 01-07-2011, 10:27 PM   #42
Member
 
Join Date: Jan 2011
Posts: 43
Default

dimming lights from large geothermal heat pump


I swapped in the old battery... its not ready the double the expected that I had caught. Its about the same as the reading I did before I changed the battery. Its a little higher than the new battery at pretty much 129/130 P2N and 260 P2P.

Starting to wonder if that 3-400V P2P stuff I was getting was real or an odd symptom of the multimeter battery getting low (though the battery low light was not on when I got that high reading and it was when I put it back in just now).

Short of the fact I've been staging my own effort to restore the ecomony with all the new **** I'm buying, are there other symptoms of significant over voltage that I might be able to match up?
atuel is offline   Reply With Quote
Old 01-07-2011, 10:37 PM   #43
Member
 
Join Date: Jan 2011
Posts: 43
Default

dimming lights from large geothermal heat pump


Quote:
Originally Posted by jimmy21 View Post
i read someone else suggest this and you blew it off, but i feel this is very important. Find out if your neighbor (that is being fed off the same transformer) is having the same lighting issues. If so, the problem may be too small of transformer.

i think you finally got over this part, but the nec does not apply to the power company. They ALWAYS use much smaller wires. I think on my house i have 4/0 aluminum on my side being fed by 1/0 on their side. Free air conductors just don't get as hot. There is very little air circulation inside a conduit and tons of air flow when its free air.

As others have said, there may be no "issue" to fix. The pump in question just might take ridiculous amounts of power to get moving. Im no pump or motor expert, but maybe their is something that can be done to lessen the current draw. Some sort of soft start.
Yeah, I know the smaller than NEC for the service lines is a common practice now for the poco.... however, it bring up a question I had on the service line being in the ground vs in the air. All my subdivisions's lines are burried. Nearest line in the air is a couple miles away along the state highway.

So the question is... is being in the ground better or worse than in the air in regard to heat dissipation. Manufactures of this 4/0 triplex seem to rate the direct burial higher than the air.
atuel is offline   Reply With Quote
Old 01-08-2011, 02:30 AM   #44
Scared Electrician
 
Saturday Cowboy's Avatar
 
Join Date: Nov 2009
Location: Colorado
Posts: 715
Default

dimming lights from large geothermal heat pump


Well let me chime in on this one. Why not fix the problem at the source?? Install capacitors or VFD at the motor! ALSO remember that the incoming feeders are not sized by the size of panel but the load calc, and by table 310.15(B)(6). which you seem to be with in, not with standing that POCO is not covered by NEC. Larger cables might help the problem, but will not fix it- just install starting help for the motor. Cheers
__________________
Ragged Trousered Philanthropist


Please follow the code - its there for your safety no matter how inconvenient.
Saturday Cowboy is offline   Reply With Quote
Old 01-08-2011, 02:46 AM   #45
Member
 
Join Date: Jan 2011
Posts: 43
Default

dimming lights from large geothermal heat pump


Quote:
Originally Posted by Saturday Cowboy View Post
Well let me chime in on this one. Why not fix the problem at the source?? Install capacitors or VFD at the motor! ALSO remember that the incoming feeders are not sized by the size of panel but the load calc, and by table 310.15(B)(6). which you seem to be with in, not with standing that POCO is not covered by NEC. Larger cables might help the problem, but will not fix it- just install starting help for the motor. Cheers
Thats certainly an option... supposedly the heat pump already had one internal to it. I was reading up on them and there were somewhat mixed reviews on them with many examples of people installing them only without the issue being resolved. Anyone have any luck with these?

I've also considered using some power regenerators on my more sensitive equipment.

atuel is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
VisionPRO Setup Functions & Heat Pump infoskr HVAC 34 11-20-2013 04:24 PM
Heat pump vs. Radiators - Opinions/Recommendations rflail HVAC 7 11-10-2010 09:56 PM
Help with Heat Pump System Wiring AlanScott HVAC 11 10-10-2010 12:19 PM
heat pump question David from MD HVAC 3 02-01-2010 08:42 PM
Heat Pump Woes Zenica HVAC 50 01-27-2009 07:37 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.