# MCP in Cold Weather



## drsparky (Nov 13, 2008)

COLD WEATHER? I had to show this post to my neighbor, we got a good laugh. It is -2F now and it will be -15 below tonight. I wore a hoodie sweatshirt over to his house. Sorry I don't have your answer but I can't see the temperature effecting a PLC.


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## GEORGE D (Apr 2, 2009)

drsparky said:


> COLD WEATHER? I had to show this post to my neighbor, we got a good laugh. It is -2F now and it will be -15 below tonight. I wore a hoodie sweatshirt over to his house. Sorry I don't have your answer but I can't see the temperature effecting a PLC.


-15, remind me not to move where you live! Laughing


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## Tyson (Jan 17, 2011)

May be the temp effected what is on the belt, or material left on the belt.


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## mattsilkwood (Sep 21, 2008)

I could see the belt freezing if it was cold enough. Maybe bearings getting stiff?


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## nitro71 (Sep 17, 2009)

Could be oil, grease, the belt stiffening up as it gets colder putting more load on the motor. Perhaps these conveyors are running close to motor capacity and the cold adds just enough load?


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## eutecticalloy (Dec 12, 2010)

nitro71 said:


> Could be oil, grease, the belt stiffening up as it gets colder putting more load on the motor. Perhaps these conveyors are running close to motor capacity and the cold adds just enough load?


I work in a food processing plant that is refrigerated. Most of our rooms are around 45 degrees fahrenheit. Are conveyors, plcs and vfds never have temp related problems. Because of the way the equipment is sanitized we often have moisture problems. I don't think 47 degree cold air would seize up a conveyor our fault a vfd.


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## nolabama (Oct 3, 2007)

GEORGE D said:


> Went to service call today in a packaging facility thats full of, vfds, plcs , etc. This place basically has no heat, just big open warehouse. Temp today there was high 47, which is colder in building especially over nite. Four similar conveyors (all do same thing, control a certain type of conveyor) were showing motor overload. Long story short, before I could even trace problem, the system started and ran just fine. None of the vfds ever displayed an error. This system has a PLC and a CNET PLC for remote access. Could cold have been the culprit amongst other things and would you recommend to install heater in cabinet?


I have VFDs that are not climate controlled and it has not been an issue.


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## drsparky (Nov 13, 2008)

Forecast was wrong, it is -22F this morning. The wood products industry around here runs in this weather, many conveyers are outdoors and unheated.


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## Southeast Power (Jan 18, 2009)

drsparky said:


> Forecast was wrong, it is -22F this morning. The wood products industry around here runs in this weather, many conveyers are outdoors and unheated.


We are getting a chill here too. Its 66 degrees here at 6:30am and was able to turn off the central air conditioning last night.

I turned the heat on yesterday and my meter read 12.6kw on the whole house. I turned it off.


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## JRaef (Mar 23, 2009)

If conveyors are DESIGNED to be used in cold weather, as they would be in a lumber mill outdoors, they are rarely a problem. But if they are designed without that in mind, then for sure the extra cold can cause an increase in starting current until the belts / grease / bearings warm up. 

Are your conveyors run by the VFDs? You weren't clear on that. If so, some VFDs allow you to program two separate ramp profiles that can be called up via digital input closures. So what I would do is set up a "Cold Start" ramp profile that gooses the system a little more when it's cold so that you get to speed faster and avoid the nuisance tripping. Tie that to a selector switch for an operator (assuming they can tell when it is cold) or even automatically to a simple little thermostat.

By the way, your thread title says "MCP in cold weather", what did you mean by MCP? Motor Circuit Protector? If so, it would never be that, and besides, if it was, you would not get an indication of "overload", you would just have a tripped breaker.

As to strip heaters in the control panel, you would do that to prevent condensation forming inside of the panel, particularly on metal surfaces like bus bars or traces on printed circuit boards that are un-powered. Condensation happens when you have moist air and the ambient temperature INSIDE of the box drops below the dew point. The dew point will vary with humidity, but can be as high as 40F. So if you put a heater in, use a thermostat set for 40F (maximum) so that it isn't running the heater all of the time.


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## GEORGE D (Apr 2, 2009)

MCP, I was referring to motor control panel but probably shoulda put MCC. Yes, all 4 of those conveyors, which are identical, are run by individual AB Powerflex 4M's. The HMI was showing the OL's and the 'OL' alarm would light on door. The actual drives never showed anything on their displays. Does that sound right?


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## Wirenuting (Sep 12, 2010)

GEORGE D said:


> MCP, I was referring to motor control panel but probably shoulda put MCC. Yes, all 4 of those conveyors, which are identical, are run by individual AB Powerflex 4M's. The HMI was showing the OL's and the 'OL' alarm would light on door. The actual drives never showed anything on their displays. Does that sound right?


The drives didn't show the o/l's being tripped?
But it showed on both the MCC bucket door and your HMI?
I would think someone reset an overload and it started or one of the overloads are set to "auto reset" and enough time had passed for the process to resume.
If only your HMI showed an overload then I would assume that you might had a (1) bad program line or (2) a bad input on your MCC's PLC.
Cold and condensation might have done it, but I wouldn't think so. Unless your MCC's are open to both inside & outside weather. If they are, shove some perma-gum in the pipes that pass thru. Seal out that cold air. 

I'm just surprised that the process started on its own. Makes you want to quickly count your fingers. :-(


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## GEORGE D (Apr 2, 2009)

Sorry if I stated that wrong, I meant when the 'system start' button was pressed it started up, not on it's own. We pressed that button a few times prior and the OL alarm would light and HMI was pinpointing those 4 conveyors as OL fault. After a while, pressed button again and started as normal, no changes were made to anything.


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## JRaef (Mar 23, 2009)

GEORGE D said:


> MCP, I was referring to motor control panel but probably shoulda put MCC. Yes, all 4 of those conveyors, which are identical, are run by individual AB Powerflex 4M's. The HMI was showing the OL's and the 'OL' alarm would light on door. The actual drives never showed anything on their displays. Does that sound right?


Something is not right here. The PF4M has built-in internal OL protection. If the drive display did not show OL, but your HMI did, I too think something is amiss in whatever is sending information to your HMI. Is there a PLC? Are the PF4Ms tied directly to it with a comm cable of some sort, or hard wired from I/O on the drive? If it's hard wired to I/O, something is not right about either the wiring or the programming of the I/O.

One other possibility is that parameter A451 is set to Auto Restart Attempts (# of attempts) and it is restarting after it cools down. This little drive doesn't retain a history of faults so you won't know if that is happening unfortunately. But if you want to check it, set A451 to 0 and see if it stays tripped.

Or are there additional OL relays down stream from the VFDs that are wired to the HMI and the OL lights?


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## JRaef (Mar 23, 2009)

By the way Wirenutting, it wouldn't be a traditional NEMA MCC with buckets etc. because you can't get the PF4M in an MCC. Probably a control panel with all the drives in one box. No big deal, just thought I'd clear that up.


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## GEORGE D (Apr 2, 2009)

JRaef said:


> Something is not right here. The PF4M has built-in internal OL protection. If the drive display did not show OL, but your HMI did, I too think something is amiss in whatever is sending information to your HMI. Is there a PLC? Are the PF4Ms tied directly to it with a comm cable of some sort, or hard wired from I/O on the drive? If it's hard wired to I/O, something is not right about either the wiring or the programming of the I/O.
> 
> One other possibility is that parameter A451 is set to Auto Restart Attempts (# of attempts) and it is restarting after it cools down. This little drive doesn't retain a history of faults so you won't know if that is happening unfortunately. But if you want to check it, set A451 to 0 and see if it stays tripped.
> 
> Or are there additional OL relays down stream from the VFDs that are wired to the HMI and the OL lights?


As I've admitted in the past, I'm not too knowledgable on controls and stuff. What I started doing when I got there before pressing anything I started checking prints to try and find a common point for all 4 drives. Never did though and I did find that most motors had an overload input coming from drive on prints but these 4 didn't. Not sure how the plc recognizes OL.


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## Wirenuting (Sep 12, 2010)

JRaef said:


> By the way Wirenutting, it wouldn't be a traditional NEMA MCC with buckets etc. because you can't get the PF4M in an MCC. Probably a control panel with all the drives in one box. No big deal, just thought I'd clear that up.


I didn't know about fitting a PF4M into the MCC. Thanks for telling me it's to large to fit. 

Like yourself I was wondering if there were other things down/up stream from his drive.
Here we had an automation company add current donuts to the load side of alot of our o/l's and used that as proof of status. They skipped using the aux contacts on the installed units, an extra charge for us, and those donuts aren't worth a hoot after awhile. They are about a cheap as a Chinese chop stick. A little bit of moisture and they don't change state.


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## RIVETER (Sep 26, 2009)

GEORGE D said:


> Went to service call today in a packaging facility thats full of, vfds, plcs , etc. This place basically has no heat, just big open warehouse. Temp today there was high 47, which is colder in building especially over nite. Four similar conveyors (all do same thing, control a certain type of conveyor) were showing motor overload. Long story short, before I could even trace problem, the system started and ran just fine. None of the vfds ever displayed an error. This system has a PLC and a CNET PLC for remote access. Could cold have been the culprit amongst other things and would you recommend to install heater in cabinet?


No. 47 degrees is insignificant.


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