Low Voltage issues

[Sylar]

I have a Marantz receiver, Panny Plasma, Dell Monitor and PC - all running through an APC Line Interactive UPS. The panny is connected to surge out of the UPS. Rest running from the UPS backup.

Been running for 3-4 years now, and I've not had any issues so far. However, In the last 2 weeks there has been power issues.
There is a welding shop that has come up close by. During the day this affects almost everything. The voltage drops from about 230V to 170V. My UPS switches over at about 185V.

The issue I have been having is, My Dell display goes off for about 1-2 secs and then comes back on. I even noticed the plasma flicker and screen jump around(never happened in the last 3+ years). When this happened, I immediately disconnected my AVR. I have currently stopped using all devices during the day.

This flickering occurs at times when,
1. UPS kicks in.
2. UPS switches back to mains (More often than #1).
This does not happen during normal power cuts or low/high voltage scenarios. It looks like it is a result of the welding.

This is my understanding of issue #1.
When a heavy load like welding is switched on around my home, the instantaneous current drawn when device is switched on is high and this gives an instantaneous drop which my UPS is unable to detect. After the current draw of that device becomes stable and if the voltage drop is below UPS cutoff, then the UPS kicks in.

Coming to my questions,
(a). I don't understand, why issue #2 occurring. Anyone?
(b). What is the recommended solution for this?

 

[slipperybidness]

This seems like a problem for your power distribution company to solve.

 

[PENG]

When it switched from UPS back to main there could be a momentary loss of power when it was not connected to either, hence the flicker. You should contact your local power distribution company about the issue. I don't think the welding shop should be connected to the residential power supply network.

 

[Sylar]

I agree this needs to be solved by the power company (state owned).
We have already raised concerns. But that is not in our hands. I am skeptical about this problem going away anytime soon.

So While I am waiting for that to solve, What are my options?

When it switched from UPS back to main there could be a momentary loss of power when it was not connected to either, hence the flicker..

Didn't get you. How is that for an instant there is no power?

 

[PENG]

Didn't get you. How is that for an instant there is no power?

I assume depending on the design there is such possibility. What type of UPS is it?

 

[slipperybidness]

I agree this needs to be solved by the power company (state owned).
We have already raised concerns. But that is not in our hands. I am skeptical about this problem going away anytime soon.

So While I am waiting for that to solve, What are my options?


Didn't get you. How is that for an instant there is no power?

Switches come in 2 flavors---Make before break or break before make

 

[PENG]

As slip said, and that depends on the design of a specific unit. Also, when it switches back presumably when the unit senses that the incoming voltage has reached the required threshold, at that very moment the voltage may not have stabilized yet, hence the flicker. It really is a problem for the local utility to sort out, UPS helps but for HT equipment I would rather just turn it off to avoid the negative effects of the thing switching back and forth.

 

[Sylar]

I assume depending on the design there is such possibility. What type of UPS is it?

I have an APC Line interactive UPS.

As slip said, and that depends on the design of a specific unit. Also, when it switches back presumably when the unit senses that the incoming voltage has reached the required threshold, at that very moment the voltage may not have stabilized yet, hence the flicker. It really is a problem for the local utility to sort out, UPS helps but for HT equipment I would rather just turn it off to avoid the negative effects of the thing switching back and forth.

Getting the power company to solve this is a long shot! We ain't that lucky back here. We have to live with what we get.

I was suggested couple of options to explore. I came over here to get some reliable suggestions and advise. I was suggested to try either of these two, i am not sure if they would help.
1. SurgeX protector.
2. An Online UPS.

 

[highfigh]

I have an APC Line interactive UPS.


Getting the power company to solve this is a long shot! We ain't that lucky back here. We have to live with what we get.

Where are you located? IT IS the power company's responsibility to supply steady power levels. If you're near an industrial park, large manufacturing or other heavy industry, that can cause this especially if this problem occurs most when they have shut-downs or reduced demand on weekends. They may need to do a controlled start-up to prevent damage to the sub-station or transformer(s).

 

[slipperybidness]

I have an APC Line interactive UPS.


Getting the power company to solve this is a long shot! We ain't that lucky back here. We have to live with what we get.

I was suggested couple of options to explore. I came over here to get some reliable suggestions and advise. I was suggested to try either of these two, i am not sure if they would help.
1. SurgeX protector.
2. An Online UPS.

Go complain to the city council or your representative.

 

[mtrycrafts]

I agree this needs to be solved by the power company (state owned).
We have already raised concerns. But that is not in our hands. I am skeptical about this problem going away anytime soon.

So While I am waiting for that to solve, What are my options?


...

Do you live i

Go complain to the city council or your representative.

He may be in a foreign country as I don't know of a state owned power/utility company in the US.
If so, his observations may be accurate, it will take a long time, if ever, to fix this.

 

[mtrycrafts]

I have an APC Line interactive UPS.


Getting the power company to solve this is a long shot! We ain't that lucky back here. We have to live with what we get.

I was suggested couple of options to explore. I came over here to get some reliable suggestions and advise. I was suggested to try either of these two, i am not sure if they would help.
1. SurgeX protector.
2. An Online UPS.

Perhaps there is a constant voltage power source available someplace, I don't know about them though.
When amps are bench tested, even here at AH, it is plugged into such a device to eliminate voltage sags.
Perhaps Gene know something about them.

 

[TLS Guy]

Do you live i

He may be in a foreign country as I don't know of a state owned power/utility company in the US.
If so, his observations may be accurate, it will take a long time, if ever, to fix this.

He lives in India, and therein lies the problem.

I would bet the line transformer nearest his residence is undersized for the load of the welding shop.

This will result in not only voltage drop but core saturation of the transformer and a high level of THD on the AC line.

I had this issue some years ago with my UPS units kicking in and I measured high levels of THD and could see it on the scope. The power company put in a bigger transformer and resolved the problem.

However our power stations and wind farms are in ND many hundreds of miles from here. In severe summer and particularly during icing conditions in the winter the power can become unstable for periods of time and the UPS units kick in and out excessively, however they are fast enough the switch is seamless.

But under the above conditions the only solution is this, until conditions improve.

If the power company will not sort this issue out, then a generator is his only solution.

I do have to run the generator for this issue from time to time, and of course during power outage, when the generator comes up in 5 seconds automatically.

The engine is one of the last V4 Wisconsin engines built. It was manufactured 1995, and I installed it with no prior use in 1999. The ignition is Fairbanks Morse magneto!

 

[slipperybidness]

He lives in India, and therein lies the problem.

I would bet the line transformer nearest his residence is undersized for the load of the welding shop.

This will result in not only voltage drop but core saturation of the transformer and a high level of THD on the AC line.

I had this issue some years ago with my UPS units kicking in and I measured high levels of THD and could see it on the scope. The power company put in a bigger transformer and resolved the problem.

However our power stations and wind farms are in ND many hundreds of miles from here. In severe summer and particularly during icing conditions in the winter the power can become unstable for periods of time and the UPS units kick in and out excessively, however they are fast enough the switch is seamless.

But under the above conditions the only solution is this, until conditions improve.

If the power company will not sort this issue out, then a generator is his only solution.

I do have to run the generator for this issue from time to time, and of course during power outage, when the generator comes up in 5 seconds automatically.

The engine is one of the last V4 Wisconsin engines built. It was manufactured 1995, and I installed it with no prior use in 1999. The ignition is Fairbanks Morse magneto!

If you have a home generator......be sure that it is exhausted properly!!!

CO alarms are also a must-have!!!!!

I'm certain that TLS knows the risks and has taken the proper actions. But for anyone else, please heed these warnings!

 

[Sylar]

He lives in India, and therein lies the problem.

I would bet the line transformer nearest his residence is undersized for the load of the welding shop.

This will result in not only voltage drop but core saturation of the transformer and a high level of THD on the AC line.

I had this issue some years ago with my UPS units kicking in and I measured high levels of THD and could see it on the scope. The power company put in a bigger transformer and resolved the problem.

Yup, I'm at India.
We are getting the residents together to raise concerns. Last week a couple of us raised complaints with the Power company, and hence It has been quite this week with no issues. I'm pretty sure, this will come back again and soon!!
Like you suggested, adding another transformer is the solution. Back here in India, the welding shop owner needs to pay for that transformer wherein lies the issues! He will just pass some cash under the table and the rest of us get hit.
I'm not sure how long they will take before the problem goes away for good.


In the meantime, I was wondering if there is something I could do at my end. A generator is out of the question.
What's wrong with an online UPS as compared to my line interactive one?
Or even a SurgeX? Won't the surgeX help here with a safe power down during such anomalies, and then back on once power is stable?

 

[PENG]

Yup, I'm at India.
We are getting the residents together to raise concerns. Last week a couple of us raised complaints with the Power company, and hence It has been quite this week with no issues. I'm pretty sure, this will come back again and soon!!
Like you suggested, adding another transformer is the solution. Back here in India, the welding shop owner needs to pay for that transformer wherein lies the issues! He will just pass some cash under the table and the rest of us get hit.
I'm not sure how long they will take before the problem goes away for good.


In the meantime, I was wondering if there is something I could do at my end. A generator is out of the question.
What's wrong with an online UPS as compared to my line interactive one?
Or even a SurgeX? Won't the surgeX help here with a safe power down during such anomalies, and then back on once power is stable?

TLS was talking about the local distribution company's transformer for the area where you and the neighboring welding shop are located. Even if the welding shop buy their own properly sized transformer will not help because if the utility company's transformer is the bottleneck.

Actually it can also be the power distribution line (underground cable or overhead lines) being under sized, or both undersized power line and transformer.

Regardless, if the voltage would in fact drop from 230V to 170V as stated in your first post, that is more than 25% drop!! No power company should allow that to happen, and if they did, the government won't allow that either. Typically power company can get away with 5% drop, 10% drop would be rare if allowed by any jurisdictions, and 25% is certainly unheard of.

With that kind of voltage drop, either you wait for your power company to fix their problem, put pressure on them by writing to your appropriate department of your local government or you have to resort to something drastic such as what TLSG was alluding to. I think most of us are trying and willing to help but we also have to be realistic about it.

There is nothing wrong with online UPS but they are design for the occasional power outage, not to deal with fluctuating supply voltage from 230V to 170V due to industrial load in an residential area and apparent undersized supply line/network (feeder cable and transformer and/or generator size etc.).

 

[TLS Guy]

If you have a home generator......be sure that it is exhausted properly!!!

CO alarms are also a must-have!!!!!

I'm certain that TLS knows the risks and has taken the proper actions. But for anyone else, please heed these warnings!

It is properly exhausted with an exhaust system I designed and had built to my spec. I installed it and there are no leaks. The muffler is from the Allis Chalmers C tractors.

Yes there are CO alarms and one right above where the generator is located.

 

[Sylar]

We finally were able to the issue resolved. We had the power company resolve this for us. Whatever they did, the Voltage now is more or less stable at 220V - 240V, which is fine. We don't face these issues anymore.

Thanks for all the help.

 

[TLS Guy]

We finally were able to the issue resolved. We had the power company resolve this for us. Whatever they did, the Voltage now is more or less stable at 220V - 240V, which is fine. We don't face these issues anymore.

Thanks for all the help.

That was the only practical and rational solution to your problem. Glad it is resolved.

 

[Sylar]

I had a couple of other issues hitting me at the same time - The industrial load, daisy chain of 2 UPS and new devices that I had added on the UPS.
I had initially daisy chained my UPS. One UPS/inverter powers the entire house and another Device UPS coming from wall socket powered by the first UPS. This daisy chaining was causing some issues in terms of load. Rewired quite a bit to eliminate the first UPS, now that too seems fine.

However, the 2nd UPS does not have enough juice in it to make it last more than 10 mins. And It does not have enough head room to deal with dynamic power. I might need to get another device UPS.