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Posted By: rperry05 Preventative Maintenance on 480v MCP - 02/14/02 06:13 PM
I work with Johnson Controls Inc. at Intercontinental Airport Houston Texas. We recently had an issue with a 3/O wire melting due to a loose lug. We have been discusing better ways to do preventative maintenance in our motor control panels. Is there a type of heat gun device that will let us know if there is a loose contact causing the wire to melt due to resistance or is tightening every lug and contact our best bet to ensure this does not happen in the future. I would greatly appreciate any input on this matter.


Bagroom Manager, Rob Perr.
I have seen thermal imaging "guns" that will sense the hot spots and will thus show you the high resistance connections.
Sorry I don't know who makes it.

Chris
Posted By: mamills Re: Preventative Maintenance on 480v MCP - 02/14/02 08:58 PM
Hi, Rob.
To add a little bit more to what Chris told you, our Fire Department recently purchased a thermal imaging camera from a company by the name of Bullard, located in Kentucky (sorry, I don't know the city). We use this for locating hot spots inside walls and ceilings (from fire, ballasts, or high resistance electric connections which are "cooking" in a hidden area). Works great, but the cost of this thing is horrendous...$9800.00! [Linked Image] Hopefully, someone can put you onto something a little more reasonable.

Mike (mamills)

Found a URL for this company... http://thermalimager.bullard.com/whybullard/
(along with an address and phone numbers)

[This message has been edited by mamills (edited 02-14-2002).]
Posted By: resqcapt19 Re: Preventative Maintenance on 480v MCP - 02/14/02 09:44 PM
Thermal imagers or temperature indicators are nice but only give you a "snapshot" of what is going at that very instant. There are available some small stick on tabs that have a permanent change in color at a specific temperature. some are marketed for electrical use. You put the sticker on the termination and then every few months you just look for the color change and take any corrective action that may be required at that time. Take a look at this site: http://www.ydxlabel.com/ydxlabel.htm

I haven't tried them yet, but they look like a good idea.
Graingers, and lots of others, also sell non contact infra red thermometers. I've used them for a long time. They don't make a permanent record of the area, but they will let you know you have a hot spot, you can also run them up and down columns of breakers and check for loose connections or overloaded conditions like that. Used them for several major maintenance programs including Dulles Airport. They also go between $300.00 and $600.00 making them a bit more palatable.
Posted By: dana1028 Re: Preventative Maintenance on 480v MCP - 02/14/02 11:00 PM
I have a Fluke 65 Infrared Thermometer - believe it cost around $100 - works like a charm...sends out an infrared beam and you can get readings on warehouse conduit 25' up in the air...breakers, lugs, etc.
I've played with the infared themometers but don't have one.

The downside (and maybe they've come out with something better) is that it took nearly a second to get a temperature reading which meant scanning a row of breakers would have been terribly slow.

And the thermometer "sees" a circular area just like a camera lense does - so at 12", you're reading the temperature of whatever its pointing at but at 25', you're reading the average temperature of a circle maybe 2' in diameter.
Posted By: resqcapt19 Re: Preventative Maintenance on 480v MCP - 02/15/02 02:40 AM
The only problem with all of the scanners or non contact thermometers is that if the connection or device is not overheating at the time of your scan, you won't see the problem.
Don(resqcapt19)
Posted By: Redsy Re: Preventative Maintenance on 480v MCP - 02/15/02 12:44 PM
You can get a reliable non contact gun-type temp. sensor for as little as $125.00 from Sunshine Instruments. Try www.measurebetter.com and contact Tom.
Posted By: dana1028 Re: Preventative Maintenance on 480v MCP - 02/15/02 03:46 PM
Maintguy - re: 2' beam pattern at 25' - the Fluke I have has a VERY tight beam - at 20' the light beam does not cover more than a 3/4" conduit....I use mine to check to hot conduit - checking for harmonics, poor connections.
Posted By: beach Re: Preventative Maintenance on 480v MCP - 02/15/02 04:35 PM
I recently purchased the fluke 65 and I paid $270 plus tax. Works great though.

Jon
Posted By: SPARKSALOT Re: Preventative Maintenance on 480v MCP - 02/16/02 04:31 AM
In the "old" days we used to just touch the conductor near where it connected to something we wanted to check out. You could easily tell if something was warmer than it should be. However, I really like the IR devices. Northern Equipement has some for less than $80. If you get one, get one with a laser targeting set up. This makes it really easy to make sure you are seeing the temp you want to check.
Don
Posted By: circuit man Re: Preventative Maintenance on 480v MCP - 02/21/02 11:52 PM
raytek makes a small hand held infared thermomter with laser sighting for around a $100 . you can find them at most good electrical supply houses & there pretty speedy. also have a few second hold on them.
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