Protect control cabinets from problematic power sources - Electrician Talk - Professional Electrical Contractors Forum
CLICK HERE AND JOIN OUR COMMUNITY TODAY, IT'S FREE!
Go Back   Electrician Talk - Professional Electrical Contractors Forum > Electrical Trade Topics > PLCs, VFDs, Motors and Controls


Like Tree10Likes
Reply
 
Thread Tools Display Modes
Old 04-02-2019, 10:55 AM   #1
Junior Member
 
Join Date: Apr 2019
Location: Central Wisconsin
Posts: 8
Rewards Points: 16
Default Protect control cabinets from problematic power sources

We have about half a dozen PLC/CNC machines in our facility, with various voltages and current loads. For discussion purposes, we can assume they are all the same.



480v 3phase input, 60a circuit breaker, 60hz


These cabinets house PLC controls and VFD's. The facility has the good luck of being hit with random power outages, brownouts and even voltage spikes from outside transformers catching on fire (literally).


Yes, I understand the incoming building power "should" be regulated and steadied by the power company. Last year, a power company technician shorted out a phase while doing service work, and just the other day a transformer randomly blew up. These incidences have created problems with our machinery, burning out circuitry and other odd problems that seem related.



I have been tasked with figuring out a way to try to protect our machines in case this happens again. I have been designing a protection box, that would control a contactor to cut off power to the machine in the event of unsteady power. This should protect from brownouts, phase imbalance or loss, and voltage fluctuation.



Has anyone worked with these devices? Is this a good one, or are the better models?


Macromatic PMD575 (i can't post links)



Thanks in advance for any advice.
sparkiez likes this.
BeerMaintenance is offline   Reply With Quote
Join Contractor Talk

Join the #1 Electrician Forum Today - It's Totally Free!

ElectricianTalk.com - Are you a Professional Electrical Contractor? If so we invite you to join our community and see what it has to offer. Our site is specifically designed for you and it's the leading place for electricians to meet online. No homeowners asking DIY questions. Just fellow tradesmen who enjoy talking about their business, their trade, and anything else that comes up. No matter what your specialty is you'll find that ElectricianTalk.com is a great community to join. Best of all it's totally free!

Join ElectricianTalk.com - Click Here JOIN FOR FREE


Warning: The topics covered on this site include activities in which there exists the potential for serious injury or death. ElectricianTalk.com DOES NOT guarantee the accuracy or completeness of any information contained on this site. Always use proper safety precaution and reference reliable outside sources before attempting any construction or remodeling task!

Sponsored Links
Advertisement
 
Old 04-02-2019, 02:26 PM   #2
Senior Member
 
Join Date: Oct 2013
Location: BC , Canada
Posts: 377
Rewards Points: 756
Default

ICM makes a 3ph line voltage monitor that would work for your application as well ....we used them on large heat pump compressors.
scotch is offline   Reply With Quote
Old 04-02-2019, 02:44 PM   #3
Senior Member
 
MikeFL's Avatar
 
Join Date: Apr 2016
Location: The Sunshine State
Posts: 4,931
Rewards Points: 1,970
Default

Welcome to the forums.

Just curious: Do you drink beer?
John Valdes likes this.
__________________
Michael Gookin, President
GPS Timers

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

(833) GPS-TIME
MikeFL is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 04-02-2019, 02:55 PM   #4
Junior Member
 
Join Date: Apr 2019
Location: Central Wisconsin
Posts: 8
Rewards Points: 16
Default

Quote:
Originally Posted by MikeFL View Post
Welcome to the forums.

Just curious: Do you drink beer?

not enough information. On or Off the job?
John Valdes and CoolWill like this.
BeerMaintenance is offline   Reply With Quote
Old 04-02-2019, 02:58 PM   #5
Junior Member
 
Join Date: Apr 2019
Location: Central Wisconsin
Posts: 8
Rewards Points: 16
Default

Quote:
Originally Posted by scotch View Post
ICM makes a 3ph line voltage monitor that would work for your application as well ....we used them on large heat pump compressors.

I see many brands that make them. Is there a reason ICM is better than others? Honestly leaning toward ABB right now, but they have so many models I am not sure which is best for my application.



I think in any case it's going to be a tough call between sensitivity/protection and reliability/no false trips.
BeerMaintenance is offline   Reply With Quote
Old 04-02-2019, 02:59 PM   #6
Senior Member
 
MikeFL's Avatar
 
Join Date: Apr 2016
Location: The Sunshine State
Posts: 4,931
Rewards Points: 1,970
Default

Well I was curious if you're around it all day, is that really what you want when you're not at work.

Friend of mine was graveyard shift manager of a large beer distributor on the east coast. We used to get unlimited beer for $5/ case, any kind we wanted. We didn't do it all the time, but if we were going fishing or having a party, we could always count on him for at least part of the day's needs being met.
__________________
Michael Gookin, President
GPS Timers

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

(833) GPS-TIME
MikeFL is offline   Reply With Quote
Old 04-02-2019, 04:37 PM   #7
Junior Member
 
Join Date: Apr 2019
Location: Central Wisconsin
Posts: 8
Rewards Points: 16
Default

Theres always cans/bottles that the machines reject for various reasons... 1mm too low filled, or damaged lables... employees get to fight over those They also sell to us at cost
MikeFL likes this.
BeerMaintenance is offline   Reply With Quote
Old 04-02-2019, 08:07 PM   #8
Senior Member
 
Rora's Avatar
 
Join Date: Jan 2017
Location: Canada
Posts: 314
Rewards Points: 624
Default

Not sure about the equipment, but since you're tasked with this just understand that you're now the fall guy whether you tune it "on the safe side" and it shuts down production for a nuisance alarm, or tune it for practical reliability then anything fails which might point the finger at the supply.

Be sure to keep management involved, give your defense on the small details up front and get them to sign off on it... ultimately make sure that you're just providing the legwork for a solution, not being responsible for it.
__________________
Self-confidence isn't 1000V rated.
Rora is offline   Reply With Quote
Old 04-02-2019, 08:44 PM   #9
Senior Member
 
MikeFL's Avatar
 
Join Date: Apr 2016
Location: The Sunshine State
Posts: 4,931
Rewards Points: 1,970
Default

Quote:
Originally Posted by Rora View Post
Not sure about the equipment, but since you're tasked with this just understand that you're now the fall guy whether you tune it "on the safe side" and it shuts down production for a nuisance alarm, or tune it for practical reliability then anything fails which might point the finger at the supply.

Be sure to keep management involved, give your defense on the small details up front and get them to sign off on it... ultimately make sure that you're just providing the legwork for a solution, not being responsible for it.
That's outstanding advice.

Another option is to tell them what their options are and let them select what protections they want.
glen1971 and Rora like this.
__________________
Michael Gookin, President
GPS Timers

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

(833) GPS-TIME
MikeFL is offline   Reply With Quote
Old 04-02-2019, 09:03 PM   #10
Senior Member
 
Join Date: Dec 2010
Location: So.Cal.
Posts: 3,224
Rewards Points: 6,397
Default

Quote:
Originally Posted by BeerMaintenance View Post
I see many brands that make them. Is there a reason ICM is better than others? Honestly leaning toward ABB right now, but they have so many models I am not sure which is best for my application.



I think in any case it's going to be a tough call between sensitivity/protection and reliability/no false trips.
Do they have a sales rep.? Maybe contact him/her, and ask. Share the blame.
__________________
-------------------------------
~ She thinks I'm crazy, but I'm just growing old~
joebanana is offline   Reply With Quote
Old 04-02-2019, 09:15 PM   #11
Senior Member
 
Rora's Avatar
 
Join Date: Jan 2017
Location: Canada
Posts: 314
Rewards Points: 624
Default

Quote:
Originally Posted by MikeFL View Post
That's outstanding advice.

Another option is to tell them what their options are and let them select what protections they want.
Even better... this also transfers the responsibility of asking the right questions onto them. If you just spec something out that they then approve, they can still claim "you didn't tell us that, it was your idea and I trusted that you made the right choice!"

They ought to vett everything you present either way, but by making it their decision puts the onus on them to make sure THEIR decision is a good one. You might still get some flak if something happens but you're a lot less likely to get fired as a scape goat.
__________________
Self-confidence isn't 1000V rated.
Rora is offline   Reply With Quote
Old 04-03-2019, 06:15 AM   #12
Senior Member
 
Join Date: May 2018
Location: florida
Posts: 1,239
Rewards Points: 694
Default

I honestly do not see the point. In real life equipment is damaged by the spike with in 1 cycle so trying to disconnect the equipment just seems to slow.

A simple phase/voltage monitoring relay should be able to shut down control power which covers some of the problems (brown outs), Ups units on the control power protect the expensive parts then a box full of surge suppressors deals with the spikes.

In florida i swear more panel space is used for suppressors and ups units than plc hardware.
gpop is offline   Reply With Quote
Old 04-03-2019, 08:25 AM   #13
Junior Member
 
Join Date: Apr 2019
Location: Central Wisconsin
Posts: 8
Rewards Points: 16
Default

Quote:
Originally Posted by MikeFL View Post
That's outstanding advice.

Another option is to tell them what their options are and let them select what protections they want.

This is what I normally do.



I'm not worried about being 'held responsible' in the way that you guys are thinking. I don't get grief for trying... they just want solutions that generally make things better.



Speaking of filtering, do the line filters do a whole lot? I have seen them factory installed for higher end machines, like Kuka robot cabinets... but they aren't much more than RC filter circuits, correct? I could see them help with electrical noise, but I don't have that problem.
BeerMaintenance is offline   Reply With Quote
Old 04-03-2019, 08:37 AM   #14
Junior Member
 
Join Date: Apr 2019
Location: Central Wisconsin
Posts: 8
Rewards Points: 16
Default

Quote:
Originally Posted by gpop View Post
I honestly do not see the point. In real life equipment is damaged by the spike with in 1 cycle so trying to disconnect the equipment just seems to slow.

A simple phase/voltage monitoring relay should be able to shut down control power which covers some of the problems (brown outs), Ups units on the control power protect the expensive parts then a box full of surge suppressors deals with the spikes.

In florida i swear more panel space is used for suppressors and ups units than plc hardware.

This is why I am asking. I understand a phase monitor won't prevent all problems, but the vast majority of the damage I have seen has been the on/off/on/brown/off/on cycles that happen during a power failure. If the power just cuts out, that usually doesn't hurt anything, but usually it cycles a few times then quits.



In my experience with Mov's, they don't last that long, and questionable how much they actually help. Anyone have more experience with them?
BeerMaintenance is offline   Reply With Quote
Old 04-03-2019, 11:45 AM   #15
Senior Member
 
Bird dog's Avatar
 
Join Date: Oct 2015
Location: South East US
Posts: 4,521
Rewards Points: 830
Default

Quote:
Originally Posted by BeerMaintenance View Post
This is why I am asking. I understand a phase monitor won't prevent all problems, but the vast majority of the damage I have seen has been the on/off/on/brown/off/on cycles that happen during a power failure. If the power just cuts out, that usually doesn't hurt anything, but usually it cycles a few times then quits.



In my experience with Mov's, they don't last that long, and questionable how much they actually help. Anyone have more experience with them?
Maybe a problem with the POCO equipment?
__________________
Popcorn munching forum observer
Bird dog is offline   Reply With Quote
Old 04-03-2019, 02:30 PM   #16
Senior Member
 
Join Date: Oct 2012
Location: Alberta Rockies
Posts: 2,584
Rewards Points: 3,528
Default

Depends what is common in your area too.. I've installed lots of Omron K8AB relays for phase loss/reversal with good success.. Tie their dry contacts into a relay/contactor to drop out the control power you want to isolate or alarm, light, etc. They can be time and voltage adjusted on site.

They don't like harmonics though! Found that out after the magic smoke got let out of one.
glen1971 is offline   Reply With Quote
Old 04-04-2019, 06:07 AM   #17
Senior Member
 
Join Date: May 2018
Location: florida
Posts: 1,239
Rewards Points: 694
Default

Quote:
Originally Posted by BeerMaintenance View Post
This is why I am asking. I understand a phase monitor won't prevent all problems, but the vast majority of the damage I have seen has been the on/off/on/brown/off/on cycles that happen during a power failure. If the power just cuts out, that usually doesn't hurt anything, but usually it cycles a few times then quits.



In my experience with Mov's, they don't last that long, and questionable how much they actually help. Anyone have more experience with them?
Mov's work but by the nature of there design they will fail. You have to work out if the mov failing is cheaper than replacing the hardware it is protecting.
(works great on the 480v side)

As for the problem you are describing i would go with a phase/voltage protection relay and install it in the control voltage circuit. If you use another relay and a button you can make a simple latched relay for control power.

Operator presses button to turn on control power, Any glitch will cut control power until the button is pressed again (this allows the operator to make the machine safe before restoring power)
splatz likes this.
gpop is offline   Reply With Quote
Old 04-04-2019, 06:55 AM   #18
Hackenschmidt
 
splatz's Avatar
 
Join Date: May 2015
Location: Parts Unknown
Posts: 7,684
Rewards Points: 2,772
Default

Quote:
Originally Posted by BeerMaintenance View Post
In my experience with Mov's, they don't last that long, and questionable how much they actually help. Anyone have more experience with them?
Everyone that uses plug in surge strips has experience with MOVs. As @gpop said, MOVs are sacrificial devices, you have to keep replacing them. Sometimes they sacrifice themselves in spectacular manner blowing apart the SPD. But they don't sound like a good fit for you.

MOVs don't start acting until the voltage is much higher than the normal supply voltage. If you buy MOV protection for 480V supply it doesn't jump in at 481V. If you have a distribution line or MV line short to your 480V supply they will jump in. They do nothing at all for brownouts, dropouts, etc. Power conditioners do that.

I know they make big power conditioners but I've only seen them in literature. I have used little power conditioners and a lot of people really swear by them.
The product brochures claim the big ones are used in medical facilities and telecom, I could see them at say an MRI clinic. They might make sense in an industrial application if the cost of the equipment wrecked and the cost of the lost production justifies it.

I am not sure what power conditioners do if you lose a phase for more than a cycle or a few cycles. If you can safely cut power (IF) I think something like the macromatic you selected is a good way to go no matter what, if you can install conditioners ahead of the equipment too, they'll have to act less often.
__________________
Whatsoever thy hand findeth to do, do it with thy might;
for there is no work, nor device, nor knowledge, nor wisdom,
in the grave, whither thou goest.
splatz is offline   Reply With Quote
Old 04-05-2019, 04:19 PM   #19
Senior Member
 
JRaef's Avatar
 
Join Date: Mar 2009
Location: SF Bay Area, California
Posts: 4,984
Rewards Points: 1,856
Default

IMHO you can't start throwing money at it until you have fully identified the nature of the problems first. There are solutions for most problems, but not many that will cover more than one. You can't cover every single contingency, it would cost way more than you might imagine, but you can cover most of them if you plan it wisely. I suggest renting or borrowing a recording meter / analyzer for a few weeks first to see what the most common issues are and start with those.

On a side note: Opening a contactor ahead of a machine every time there is a glitch will only serve the purpose of letting you know how MANY glitches in power take place every day, because it will be a serious annoyance and likely end up disabled in no time. It's better to accept the fact that "stuff" happens and plan for it accordingly.
sparkiez likes this.
__________________
"If you don't know where you're going, then any direction will do." -- Lewis Carroll
JRaef is offline   Reply With Quote
Old 05-01-2019, 11:09 AM   #20
Junior Member
 
Join Date: Apr 2019
Location: Central Wisconsin
Posts: 8
Rewards Points: 16
Default

Thanks everyone for the input. It's all about what I expected.



I don't see it as "throwing money at it" when I am only talking about $500 worth of parts to protect a $50k cabinet.



I also know that some of the cabinets do have 'power conditioners' built into them, but they are small and passive... it appears they are basically LC filters.



I suppose it wouldnt hurt to look into MOV's for each cabinet, to add on top of my phase monitor relay, as long as I replace them on a schedule, like bi-annual.
BeerMaintenance is offline   Reply With Quote
Reply

Thread Tools
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
VFD speed control from external sources icyhammer General Electrical Discussion 19 05-19-2018 06:52 AM
Generac transformer control transformer troubleshoot MTW Industrial Electrical Forum 2 03-05-2018 08:16 PM
Advice needed! Electrician and EE degree Dale333 Electrician Apprentice Forum 16 11-30-2017 05:21 PM
Septic pump control box power (resi) MTW NEC Code Forum 38 08-07-2017 11:20 PM
Control Room Power Distribution izatso General Electrical Discussion 2 07-05-2017 06:30 PM


All times are GMT -4. The time now is 04:34 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.1
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Our Pro Sites Network
ContractorTalk.com | DrywallTalk.com | HVACSite.com | PaintTalk.com | PlumbingZone.com | RoofingTalk.com