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antidelldude

join:2003-12-22
Rochester, MI

Lights dimming during Sump Pump and A/C Start

This one has been driving me nuts for a while now and I can't figure it out. I have a 100amp service. My house's draw is minimal. With all my incandescent lights on, my computers on, network gear, toaster, tv, washer, dryer, etc... I draw right around 55 amps at 110. My circuit panel is balanced, with everything on, I get an almost even draw on each leg.

*Had the power company come out, they replaced the line from my house to the poll, the Neutral was cut (I must have had a VERY good ground). The transformer is three polls down from my house.
*Replaced wire from power company to meter housing AND replaced meter housing.
*Balanced the electrical panel and got as many lights off the leg my sump pumps were on.
*Tightened all the wires coming from the meter into the electrical panel (you can bet I had the electrician torque the hell out of the bolts on the meter can as well).
*Had the power company check the transformer (but I think this is the issue).

What else can I do? I had an electrician do most of the work and he is stumped as well.

I can't just get over it either. One of my Sump pumps runs every 3-5 minutes and it's distracting. (which I also had checked, my land is just wet). For my A/C I got a 3 wire hard start kit, but the HVAC tech I asked about installing it, wouldn't. He said even the nice ones can damage the compressor... In the summer, my lights could dim 30 times an hour between the two sumps and A/C...


tschmidt
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join:2000-11-12
Milford, NH
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Have you spoken to your neighbors served by the same transformer? Are they seeing flickering lights? If it is a problem with the feeder or transformer they should be seeing flicker just like you. Do you notice any flicker at other times when pump/AC are not starting?

Did your electrician hook up a line voltage monitor. That should provide documentation to the utility if there is a problem. Motors draw a lot of current at startup so minor monetary dimming is not uncommon. From your description sounds like it is more than minor.

/tom


nunya
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O Fallon, MO
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reply to antidelldude
said by antidelldude:

What else can I do? I had an electrician do most of the work and he is stumped as well.

It's normal for lights to dim when a motor starts. It can be annoying, but sometimes that's just the way it is. I share a transformer with 4 other houses. Every time one of my neighbors A/C kicks on or they use a circular saw my lights blink. The power company isn't going to install a larger / dedicated transformer unless the old one blows up.
--
If someone refers to herself / himself as a "guru", they probably aren't.

antidelldude

join:2003-12-22
Rochester, MI
Wow, you're issue is sounds worse than mine. I'm lucky that the other homes on my transformer don't have basements or air conditioners (lucky me...). I wonder how bad my issue would be then.

I get about a 9 volt drop on the leg that one of my sump pumps draw from. At this point, I really think it's the transformer but a 9 volt drop isn't enough for the power company to do anything, but it is more than enough for me to notice, every, single, time. My old home didn't have this issue so I guess it's a matter of getting used to it or bugging the hell out of my power company. I just needed to make sure I wasn't missing something stupid.

Anybody ever try to wire up a soft-start to their sump pump like they have on industrial motors?


PSWired

join:2006-03-26
Annapolis, MD
I haven't tried this, but here's what I'd be looking at:

»www.mouser.com/ProductDetail/Cry···2vIdc%3d

»www.mouser.com/ds/2/93/M_CS-33227.pdf

120V soft start relay, 25A, DC control. You'll need to provide an enclosure and rewire your float switch. There's an internal potentiometer on this model to control the ramp time. This particular model has soft start and stop but is available in soft start only configurations.


PSWired

join:2006-03-26
Annapolis, MD
Also if you decide to do this and your sump pump is required to keep the place from flooding, I'd be adding a backup pump with a conventional mechanical float switch in case the soft starter (or the pump motor for that matter) burns up.

laserfan

join:2005-01-14
Texas
reply to antidelldude
It might actually be easier & cheaper to replace at least the "most noticeable" of the incandescent lamps with Fluorescent or LED types, which should not AFAIK exhibit the problem.

Our incandescents dim slightly when our heat pumps kick-in, but it seems to be a very common problem where we live and we've gotten to where it doesn't bother us anymore. Of course, 30 times an hour is something else again...I'd probably be looking to do something with at least the sump pump just as you're thinking...


Jack_in_VA
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join:2007-11-26
North, VA
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reply to antidelldude
said by antidelldude:

I can't just get over it either. One of my Sump pumps runs every 3-5 minutes and it's distracting. (which I also had checked, my land is just wet).

Your house must be sitting on a natural spring to have enough water infiltration to require that much pump run. That many starts is hard on the pump motor and switch.

If I were you I would install a backup pump with the float switch set just a little higher than the one in use now. If it fails the backup would prevent the basement from flooding.



Phibian

join:2009-06-01
Ottawa, ON
Reviews:
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reply to PSWired
Cool. Would something like this work on a boiler circulation pump (1/6 hp I think)? When it starts up it sends an annoying clang through all the pipes throughout the house. I'd seen soft start motor controls but they were almost all three phase and way more complicated than I was looking for.


stevek1949
We're not in Kansas anymore
Premium
join:2002-11-13
Virginia Beach, VA
said by Phibian:

Would something like this work on a boiler circulation pump (1/6 hp I think)?

That sounds like water hammer within the pipes and not the pump itself. Sounds like an expansion tank would be needed. but I am not a plumber. I could be wrong!


Phibian

join:2009-06-01
Ottawa, ON
Reviews:
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There is an expansion tank. The issue is that when the pump starts there it goes from zero to full in a fraction of a second and creates the noise. There is a spring coupler on it that is supposed to dampen the starting energy but it does little for the noise issue. The noise only happens on start up. Don't want to hijack the thread here but it seems to me that this may be exactly what I'm looking for. I guess I'd worry a bit about it being bad for the motor. Reading the specs the other question I have is how long a ramp up would I want? Would one second be enough?

iknow_t

join:2012-05-03
said by Phibian:

There is an expansion tank. The issue is that when the pump starts there it goes from zero to full in a fraction of a second and creates the noise. There is a spring coupler on it that is supposed to dampen the starting energy but it does little for the noise issue. The noise only happens on start up. Don't want to hijack the thread here but it seems to me that this may be exactly what I'm looking for. I guess I'd worry a bit about it being bad for the motor. Reading the specs the other question I have is how long a ramp up would I want? Would one second be enough?

that's the old style pump, the new one's are one piece, and quiet, and use less current. like this, this should do the trick. »www.pexsupply.com/Taco-007-F5-00···odCAkAdA

iknow_t

join:2012-05-03
reply to antidelldude
OP this problem varies from area to area, I don't get this problem. there are AVR's that could be used to stop this, but they are expensive.

foo11223344

join:2004-01-09
Tarrytown, NY
reply to antidelldude
Would it work to attach a large capacitor (non-polarized and of suitable voltage rating) across the hot/netural lines as they enter the sump pump? Seems like this would allow the pump and float to remain as they are.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
And that would accomplish what?

foo11223344

join:2004-01-09
Tarrytown, NY
It would supply the inrush current as the motor started, helping to reduce the voltage sag in the rest of the house.


shdesigns
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join:2000-12-01
Stone Mountain, GA
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said by foo11223344:

It would supply the inrush current as the motor started, helping to reduce the voltage sag in the rest of the house.

No, it would just draw more current. This is AC, the cap will completely charge/discharge on each half AC cycle. It might improve the power factor a bit.

The inrush current lasts for dozens of AC cycles.
--
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Embedded Systems Consultant,
SHDesigns home - DIY Welder

HarryH3
Premium
join:2005-02-21
kudos:3
Reviews:
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reply to antidelldude
As a point of reference, we have two 3.5-ton central A/C units and a 2 HP pump for the pool. Our lights don't dim at all when any of them turn on and the A/C units get quite a workout here in Central Texas during the summer. There are 3 houses, all with similar loads, served by a 35kv transformer.

patcat88

join:2002-04-05
Jamaica, NY
kudos:1
reply to antidelldude
Install thinner and/or longer wire to the AC or sump pump. Or put the motor on a isolation transformer that is rated for exactly the running amps of the motor. During startup during the higher amp draw, causing much larger voltage drop at the motor by choking the current will stop the lights from dimming.

antidelldude

join:2003-12-22
Rochester, MI

1 edit
reply to Jack_in_VA
Way ahead of you on that one. Two sumps, and a backup DC with a gigantic deep cycle marine battery.

Edit: And z-wave water alarms


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
+1

Very proactive


TheTechGuru

join:2004-03-25
TEXAS
kudos:2
Reviews:
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1 edit
reply to antidelldude
said by antidelldude:

This one has been driving me nuts for a while now and I can't figure it out. I have a 100amp service. My house's draw is minimal. With all my incandescent lights on, my computers on, network gear, toaster, tv, washer, dryer, etc... I draw right around 55 amps at 110. My circuit panel is balanced, with everything on, I get an almost even draw on each leg.

*Had the power company come out, they replaced the line from my house to the poll, the Neutral was cut (I must have had a VERY good ground). The transformer is three polls down from my house.
*Replaced wire from power company to meter housing AND replaced meter housing.
*Balanced the electrical panel and got as many lights off the leg my sump pumps were on.
*Tightened all the wires coming from the meter into the electrical panel (you can bet I had the electrician torque the hell out of the bolts on the meter can as well).
*Had the power company check the transformer (but I think this is the issue).

What else can I do? I had an electrician do most of the work and he is stumped as well.

I can't just get over it either. One of my Sump pumps runs every 3-5 minutes and it's distracting. (which I also had checked, my land is just wet). For my A/C I got a 3 wire hard start kit, but the HVAC tech I asked about installing it, wouldn't. He said even the nice ones can damage the compressor... In the summer, my lights could dim 30 times an hour between the two sumps and A/C...

I believe a lot of the problem is that very long distance to the transformer.

Try to get the poco to install a transformer on the pole nearest your house and run a 200amp supply line from it to your house. Remember those lines are aluminum which does not carry electricity all that efficiently compared to copper.

Then also switch to a 240V pump.

There is one other way around this that will guarantee your problem will be solved, order 3 phase power supply from the poco, put the pumps and ac on phase 1 and 2 and your lights on phase 3, lol.

Thanks for reminding me I need to complain to my poco, my lights dim and stay dimmed when the electric heat is on, my panel is 200amp but the line to my house looks like 100amp or less and is quite long.

--
CompTIA Network+ Certified

iknow_t

join:2012-05-03
reply to antidelldude
checking around, it seems that a 10KVA rating per house is normal. so that's 55amps*220V=12.1K just for what you are using there, although pole transformers are underrated for safety. the transformers used in urban areas are usually much larger, hence less voltage drop.


nunya
LXI 483
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join:2000-12-23
O Fallon, MO
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We usually use either 240V or 208V here in the USA.
We have 5 houses on a 25 kVA transformer. The first one lasted 51 years. It blew up on the first hot day of summer a few years ago. We'll see how long this one lasts.
--
If someone refers to herself / himself as a "guru", they probably aren't.

iknow_t

join:2012-05-03
said by nunya:

We usually use either 240V or 208V here in the USA.
We have 5 houses on a 25 kVA transformer. The first one lasted 51 years. It blew up on the first hot day of summer a few years ago. We'll see how long this one lasts.

nominal. notice that the OP is getting 110V off one leg. in some areas of NYC, on a hot day, the voltage can drop to 90V. it varies with the area.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
reply to nunya
said by nunya:

We usually use either 240V or 208V here in the USA.
We have 5 houses on a 25 kVA transformer. The first one lasted 51 years. It blew up on the first hot day of summer a few years ago. We'll see how long this one lasts.

I have a 50 kva now for 5 houses. 2 are not occupied full time. I moved here in 1989 and it was a 15 kva, they replaced it with a 25 kva and they replaced it with a 50 kva. None of the replaced transformers failed. I don't know what the reason was for changing them but we're in good shape now. Voltage is steady 120/240.

laserfan

join:2005-01-14
Texas
reply to TheTechGuru
said by TheTechGuru:

I need to complain to my poco, my lights dim and stay dimmed when the electric heat is on, my panel is 200amp but the line to my house looks like 100amp or less and is quite long.

"How long" I wonder. My transformer and meter/200A service panel are on a pole together, but 165 feet from our house connected IIRC by 2/0. We have slight incandescent dim/flicker with heat pump turn-on.

I blame the builder for at least 40 feet of the 165' distance, though honestly I doubt that I wouldn't flicker at least a tiny bit even at 125 feet.


PSWired

join:2006-03-26
Annapolis, MD

1 recommendation

reply to Phibian
said by Phibian:

Cool. Would something like this work on a boiler circulation pump (1/6 hp I think)? When it starts up it sends an annoying clang through all the pipes throughout the house. I'd seen soft start motor controls but they were almost all three phase and way more complicated than I was looking for.

Yes, I'd say it would, but as others posted you'd be better off just switching to a cartridge circulator.


TheTechGuru

join:2004-03-25
TEXAS
kudos:2
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reply to laserfan
said by laserfan:

said by TheTechGuru:

I need to complain to my poco, my lights dim and stay dimmed when the electric heat is on, my panel is 200amp but the line to my house looks like 100amp or less and is quite long.

"How long" I wonder. My transformer and meter/200A service panel are on a pole together, but 165 feet from our house connected IIRC by 2/0. We have slight incandescent dim/flicker with heat pump turn-on.

I blame the builder for at least 40 feet of the 165' distance, though honestly I doubt that I wouldn't flicker at least a tiny bit even at 125 feet.

Well it's very odd for the meter to not be at the house unless it's a mobile home but there is one good thing, you control what's after the meter, so you can at your own discretion and cost have that line replaced. Replace it with copper.

I don't put up with a meter not being at the house, the further the meter is from the house the more resistance between the meter and the house causing a higher bill for energy wasted as heat in the long line.
--
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laserfan

join:2005-01-14
Texas
Well there might have been a better way to do this, but first-in was the meter, service panel, and an RV jack. That's all, with a fair notion of where the main house would eventually be located. A year or so later we dug a well, connected some 40 feet away, the following year a garage/guest quarters building 180' in another direction, the next year our main house, and separate pool equipment room. Ten years later we built a storage barn. Five subpanels total from the main service panel/meter at the pole. All copper, all to-code afaik.

I'd like to install a whole-house generator but given we've already maxxed-out our 200A service, with wires running-out in all directions, I expect it would be very be costly to implement i.e. with labor/electrical at least as much-if-not-more as the gen itself.