Which Surge Protector is better?

[kwired]

I would suggest monitoring the voltage for a 24 or 48 hour period. For starters just use a multi-meter with a MIN-MAX function. If you can show the POCO their supply voltage is exceeding the panel rating by a volt or two they might put a recording device of their own on it.

If nominal voltage is supposed to be 240 then the POCO is likely not to get too concerned over a volt or two. You need to be outside of the 228-252 window in most cases to get any action from the POCO.

Around here I expect to see 245-250 most of the time on a 240 volt service with little or no load.

I just can't imagine a factory engineer wanting to discuss a $200 item

Can you imagine him discussing the thousands of dollars of equimpent or loss of production it may be protecting?

 

[mkgrady]

If nominal voltage is supposed to be 240 then the POCO is likely not to get too concerned over a volt or two. You need to be outside of the 228-252 window in most cases to get any action from the POCO.

Around here I expect to see 245-250 most of the time on a 240 volt service with little or no load.



Can you imagine him discussing the thousands of dollars of equimpent or loss of production it may be protecting?

I think he was suggesting if there is a neutral problem it might not show up while I'm looking at my meter and they it may show up over a period of a couple of days.

No, I can't imagine a Siemens engineer spending any time helping me figure out which would be the best product because I only need one or two of these items. I don't think he cares about my customers property of potential losses.

 

[kwired]

I think he was suggesting if there is a neutral problem it might not show up while I'm looking at my meter and they it may show up over a period of a couple of days.

No, I can't imagine a Siemens engineer spending any time helping me figure out which would be the best product because I only need one or two of these items. I don't think he cares about my customers property of potential losses.

You want to watch that meter for a couple days or let a recording meter watch it? The recording meter is not too expensive and is not distracted as easily when you look at it this way.

I guess when "factory engineer" was mentioned I envisioned the engineer responsible for the installation and not a product engineer from Siemens. Do you really think you will ever talk to a Siemens engineer unless the conversation is related to a multimillion dollar deal with Siemens? Anything less than that - order from the catalogs - and add any necessary available options offered in the catalog.

 

[Fulthrotl]

This customer with a small office building is having problems with damaged electrical equipment. I'm told he has had to replace a couple of small motors and a fancy gas water heater in a short period of time. He asked me to see if I can find a problem with his system.

The service is 400 amps single phase, 120/240 with two 200 amp main panels. All connections in meter socket, MCBs and all circuit breakers seem good. At all points in the panels the voltage is 124/248. A little high but I'm thinking it is not damaging equipment. The power company has already been out to say the system on their end is OK.

My first thought is to install surge protection on both panels with the idea that it can't hurt and maybe it will help. Siemens makes a device that plugs in like a breaker. It takes the place of two CBs and it also contains two single pole breakers to reconnect the old circuits (there is no space in either panel). The cat # is QSA2020. There is also a unit that adds TVSS to the end of the catalog number. I'm wondering what the difference between the units is. In looking at the cut sheet the TVSS unit costs more and provides more insurance on connected equipment but I don't really care about that much. The cheaper unit is rated higher in Joules which seems better. What really has me stumped is the Intiial Clamping Level. The cheap one is rated 360 volts and the TVSS is rated 240 volts. I don't know what that means. Since the voltage is already over 240 how would that effect the one rated 240 volts?

Which unit would be better ? Any other ideas?

how are the motors failing? smoked start/run caps, or something else...

with the gas water heater, i'm thinking the controls got smoked, as in a tankless one.

either case, i'm thinking even a 20% overvoltage situation briefly won't toast them.
it may shorten their service life, but not make them into a flashbulb.
sounds like you have flashbulbs.

were they on the same subpanel, as you said there are two 200a. subs....

my gut instinct is you have a floating neutral, and what burns up is what is on
when the panels start self balancing.... the poco said "all is well"..... i've heard
that before, and it may be true, but make yourself a fault tree showing what
failed, what panel it was hooked to when it failed, and look for common denominators.

and you can check everything on the neutral up to where you hit the poco, so if that stuff
is all tight, and the ufer, cold water, and building steel, etc is good... that leaves the poco.

motors are a pain, he should be happy he hasn't smoked the fileserver his buisness is
running on, yet.....

the pooters are on ups's, right?

 

[mkgrady]

Unfortunately I don't know much about the past problems or the existing conditions except what I have revealed here. This is my first involvement at the site. THe placed was wired a year or two ago and he doesn't want to rely solely on the original electrician to tell him if the wiring is defective. I'm being paid to make an assesment as to whether or not there are any major flaws with the current wiring. I have told the owner that I have not found any obvious problems but to determine more than that could be costly. I also sugested surge suppression might fix a surge problem if that it what he is having.

 

[mkgrady]

You want to watch that meter for a couple days or let a recording meter watch it? The recording meter is not too expensive and is not distracted as easily when you look at it this way.

I assume I would have to connect a recording voltmeter for a month or so. That is not an expensive meter? I just assumed it is. How much do you think I would pay for or rent one for? I don't picture myself needing one often enough to own one.

 

[kwired]

I assume I would have to connect a recording voltmeter for a month or so. That is not an expensive meter? I just assumed it is. How much do you think I would pay for or rent one for? I don't picture myself needing one often enough to own one.

What I meant was it is cheaper to rent one than to watch a non recording meter for long periods, and the recording meter will not get distracted or fall asleep and miss something.

If you want to make sure connections are sound load things up with non sensitive resistance loads and monitor voltage. Be sure to imbalance loads so there is significant load on the neutral. If there is a bad connection it will make itself known when heavily loaded like this.

 

[mkgrady]

If you want to make sure connections are sound load things up with non sensitive resistance loads and monitor voltage. Be sure to imbalance loads so there is significant load on the neutral. If there is a bad connection it will make itself known when heavily loaded like this.

OK got it. That's what I will do if he decides to spend some more money on looking for a problem.

 

[PetrosA]

I don't know how much it costs to rent a power recorder, but new they start from about $1500 for something that just monitors one hot wire to well over $10,000 for Fluke 3 phase models. If you're doing an assessment, it might be worth looking into getting at least two datalogging multimeters which would allow you to record voltage fluctuations over an extended period of time. It won't be as precise as a power analyzer, but it will help.

I'm going to mention a product I've been beta testing because I think it has a lot of potential in cases like this where a customer may not see the need for the expense of full power analyzing or for little guys like me who can't afford that kind of equipment. I have three Agilent DMMs and a clamp meter, all of which have an IR port. My U1272A and U1242B both do datalogging to internal memory, but the product I just finished beta testing is the U1177A which is a Bluetooth module that attaches to any of the Agilent handhelds, and communicates with either an Android phone or Android tablet. There is software (free) that will stream data from up to three DMMs simultaneously and log it, graph it, perform math functions, and export for later analysis. Depending on which DMM you get, you can get a set of three DMMs with Bluetooth modules for as little as $300 (there's a promotion on the modules, so they're free right now with the purchase of a DMM). The avertised price for the modules is $48, so it makes sense to take advantage of the promo.

With this setup, you could easily monitor voltage of both hots in one panel plus one hot in the second panel for a 24-48 hour period. That should be enough information to decide whether there are problems with the neutral or not, or whether there are any meaningful spikes happening, as well as whether it's just affecting one panel or both.

Here's a link to a video I made that shows some of what the system does (with just the meter software):

http://www.youtube.com/watch?v=tSodrChd4iU

I'll try and do a screen shot of the datalogging software so you get an idea of what it looks like.

Disclaimer: I don't work for Agilent. I took part in a beta testing program.

 

[mkgrady]

Thanks for posting that video petrosra. It's amazing what can be done nowadays

 

[templdl]

I don't know how much it costs to rent a power recorder, but new they start from about $1500 for something that just monitors one hot wire to well over $10,000 for Fluke 3 phase models. If you're doing an assessment, it might be worth looking into getting at least two datalogging multimeters which would allow you to record voltage fluctuations over an extended period of time. It won't be as precise as a power analyzer, but it will help.

I'm going to mention a product I've been beta testing because I think it has a lot of potential in cases like this where a customer may not see the need for the expense of full power analyzing or for little guys like me who can't afford that kind of equipment. I have three Agilent DMMs and a clamp meter, all of which have an IR port. My U1272A and U1242B both do datalogging to internal memory, but the product I just finished beta testing is the U1177A which is a Bluetooth module that attaches to any of the Agilent handhelds, and communicates with either an Android phone or Android tablet. There is software (free) that will stream data from up to three DMMs simultaneously and log it, graph it, perform math functions, and export for later analysis. Depending on which DMM you get, you can get a set of three DMMs with Bluetooth modules for as little as $300 (there's a promotion on the modules, so they're free right now with the purchase of a DMM). The avertised price for the modules is $48, so it makes sense to take advantage of the promo.

With this setup, you could easily monitor voltage of both hots in one panel plus one hot in the second panel for a 24-48 hour period. That should be enough information to decide whether there are problems with the neutral or not, or whether there are any meaningful spikes happening, as well as whether it's just affecting one panel or both.

Here's a link to a video I made that shows some of what the system does (with just the meter software):

http://www.youtube.com/watch?v=tSodrChd4iU

I'll try and do a screen shot of the datalogging software so you get an idea of what it looks like.

Disclaimer: I don't work for Agilent. I took part in a beta testing program.

Boy, this is a bit better than the old brush recorder if anybody remembers those which were the only game in town many years ago.

 

[PetrosA]

Here are a couple of screenshots from my tablet running the Agilent Logger software. There are three DMMs sampling at 1 sample per second. There is a math function that the user can define, for instance with two meters reading voltage; (MA+MB)/2 would give you the average between these two meters, with one reading voltage and the other current; MA*MB would give you watts. Math can be applied to all three DMMs. It gives you some basic power quality analyzing ability.

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