# Purple discoloration on bus bar **URL:** \ **Category:** Electrical Inspections\ **Created:** [March 30, 2017, 8:05pm UTC](https://forum.nachi.org/t/purple-discoloration-on-bus-bar/115070 "2017-03-30T20:05:43Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![sstaggs](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sstaggs/32/1777_2.png) [@sstaggs](https://forum.nachi.org/u/sstaggs)\ **Post date:** [March 30, 2017, 8:05pm UTC](https://forum.nachi.org/t/purple-discoloration-on-bus-bar/115070/1 "2017-03-30T20:05:43Z")
Today’s home inspection I had some discoloration on the neutral and ground bus bar. Seems like this would be caused by heat. I searched on google and through the InterNACHI electrical class and can’t find anything. The panel was located in the garage and no chemicals were found near by. I do not own an IR camera and I only used my IR Thermometer and there was no spikes in temperature. Could this be a loose connection to the bar? My camera flash did not go off and stayed the same when I moved around. ![IMG_20170330_102753.jpg](https://global.discourse-cdn.com/internachi/original/3X/e/7/e7938e640cb78ad587550881f0bda1b185d470f9.jpeg) ![IMG_20170330_102749.jpg](https://global.discourse-cdn.com/internachi/original/3X/a/6/a6212d1d5068f6695ef35f539ef144044bb30c67.jpeg) ---
**Author:** ![rmeier2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rmeier2/32/59909_2.png) [@rmeier2](https://forum.nachi.org/u/rmeier2)\ **Post date:** [March 30, 2017, 8:53pm UTC](https://forum.nachi.org/t/purple-discoloration-on-bus-bar/115070/2 "2017-03-30T20:53:44Z")
Looks OK from the photo’s since there is no other visible signs of a problem. I’ve seen something similar on GE panels where the ungrounded lug area became discolored. The multiple neutrals under one screw is a problem though. Each neutral requires it’s own hole in the bus. ---
**Author:** ![sstaggs](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sstaggs/32/1777_2.png) [@sstaggs](https://forum.nachi.org/u/sstaggs)\ **Post date:** [March 30, 2017, 9:13pm UTC](https://forum.nachi.org/t/purple-discoloration-on-bus-bar/115070/3 "2017-03-30T21:13:41Z")
> [@Robert\_Meier](#): > > Looks OK from the photo’s since there is no other visible signs of a problem. I’ve seen something similar on GE panels where the ungrounded lug area became discolored. > > The multiple neutrals under one screw is a problem though. Each neutral requires it’s own hole in the bus. Ok awesome, I haven’t seen that before and wanted to do some research. I am calling out the multiple neutrals on one lug. On a similar note, should we call out the same for multiple grounds on one lug? ---
**Author:** ![rmeier2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/rmeier2/32/59909_2.png) [@rmeier2](https://forum.nachi.org/u/rmeier2)\ **Post date:** [March 30, 2017, 9:46pm UTC](https://forum.nachi.org/t/purple-discoloration-on-bus-bar/115070/4 "2017-03-30T21:46:20Z")
> [@sstaggs](#): > > Ok awesome, I haven’t seen that before and wanted to do some research. I am calling out the multiple neutrals on one lug. > > On a similar note, should we call out the same for multiple grounds on one lug? Many panels will accept 2 or 3 equipment grounding conductors (EGC’s) under one screw. That information should be on the labeling within the panel. ![](https://global.discourse-cdn.com/internachi/original/4X/5/f/c/5fcf159060cb6b581d8816b386625fc435a5e26b.jpeg) ---
**Author:** ![sstaggs](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sstaggs/32/1777_2.png) [@sstaggs](https://forum.nachi.org/u/sstaggs)\ **Post date:** [March 30, 2017, 10:05pm UTC](https://forum.nachi.org/t/purple-discoloration-on-bus-bar/115070/5 "2017-03-30T22:05:45Z")
> [@Robert\_Meier](#): > > Many panels will accept 2 or 3 equipment grounding conductors (EGC’s) under one screw. That information should be on the labeling within the panel. > > [http://i191.photobucket.com/albums/z303/starstream4627/ground-neutral-terminalbars.jpg?t=1233679569](http://i191.photobucket.com/albums/z303/starstream4627/ground-neutral-terminalbars.jpg?t=1233679569) Awesome, thank you for the input Robert! ---
**Author:** ![Jim\_Port](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jim\_Port](https://forum.nachi.org/u/Jim_Port)\ **Post date:** [March 30, 2017, 10:50pm UTC](https://forum.nachi.org/t/purple-discoloration-on-bus-bar/115070/6 "2017-03-30T22:50:55Z")
Since both bars like similar I don’t think it is an issue of heating. Robert did point out the other issues. ---
**Author:** ![cdeakins](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cdeakins/32/438_2.png) [@cdeakins](https://forum.nachi.org/u/cdeakins)\ **Post date:** [April 2, 2017, 5:19am UTC](https://forum.nachi.org/t/purple-discoloration-on-bus-bar/115070/7 "2017-04-02T05:19:05Z")
also the white wires connected to breakers should be re-identified with red tape. ---
**Author:** ![Jim\_Port](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jim\_Port](https://forum.nachi.org/u/Jim_Port)\ **Post date:** [April 2, 2017, 10:36pm UTC](https://forum.nachi.org/t/purple-discoloration-on-bus-bar/115070/8 "2017-04-02T22:36:14Z")
> [@cdeakins](#): > > also the white wires connected to breakers should be re-identified with red tape. The tape or marker can be any color other than green, green with a yellow stripe or grey. ---
**Author:** ![cevans](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cevans/32/244194_2.png) [@cevans](https://forum.nachi.org/u/cevans)\ **Post date:** [April 2, 2017, 10:42pm UTC](https://forum.nachi.org/t/purple-discoloration-on-bus-bar/115070/9 "2017-04-02T22:42:42Z")
> [@Jim\_Port](#): > > The tape or marker can be any color other than green, green with a yellow stripe or grey. I chose white :mrgreen: ---
**Author:** ![jjonas](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jjonas/32/301755_2.png) [@jjonas](https://forum.nachi.org/u/jjonas)\ **Post date:** [April 2, 2017, 10:54pm UTC](https://forum.nachi.org/t/purple-discoloration-on-bus-bar/115070/10 "2017-04-02T22:54:52Z")
[https://www.quora.com/How-do-high-temperatures-cause-the-color-of-metal-to-change](https://www.quora.com/How-do-high-temperatures-cause-the-color-of-metal-to-change)