Temps and MH Lighting

[mtcnokc]

We have installed HPS fixtures in a metal building, no more than 7 fixtures per circuit, fixtures drawing 2 amps each, and the home run has 6 conductorss, w/ 1 ground wire.

The Inspector has determined that the heat that this building will see in the summer time, will be in the 140 to 160 degree area, and wants us to replace the #12 wiring with #10.

This building has the normal air turbines as well as power ventalitaion.This build is built with galv material which has has refelcted properties.

My calcuations at worst have me with derated wire and assuming no more than 120 degrees that this building would see, we show that the number 12's still are acceptable.

Anyone have insight to this ?

 

[ryan_618]

Re: Temps and MH Lighting

Why did use 120 degrees in your calculations when the inspector told you 140-160 degrees?

 

[bennie]

Re: Temps and MH Lighting

Does the inspector have documented evidence that the temperatures are present?

 

[charlie]

Re: Temps and MH Lighting

Originally posted by Bennie:
Does the inspector have documented evidence that the temperatures are present?

Does mtcnokc have documented evidence that the temperatures are not present? Remember, the inspector is always correct.

 

[bennie]

Re: Temps and MH Lighting

Charlie: Good response What happened to the innocent until proven guilty, and the burden of proof is with the accuser. The accused is not required to prove innocence.

 

[iwire]

Re: Temps and MH Lighting

Just curious, if the inspector is correct and the ambient temp is reaching 140 to 160 degrees are the fixtures rated for use in this temp? :roll:

I think this is a BS call by the inspector and if you end up conceding to it the next logical question from the inspector would be about the suitability of the fixture in that temp.

I have no idea how you would prove the ambient temp either way without taking temp readings at the site for a long period of time.

Did you upset this guy before this issue came up? :roll:

 

[bob]

Re: Temps and MH Lighting

mtcnock
Where do you live. I live on the Gulf Coast and my attic does not get that hot. With the air vents and power ventilation I can't see those temps. With 14 amps on the #12 conductor the load is way below capacity. Isq heat build up compared with #10 would not be much different.

 

[brian john]

Re: Temps and MH Lighting

Remember, the inspector is always correct.

The inspector is not always correct, of course proving this or convincing him/her of this is another thing.
We find inspectors wrong as well as contractors.

 

[frenchelectrican]

Re: Temps and MH Lighting

a quick point of question about the wire run. is the wire is running near the roof or what ?? and how high the fixure are mounted ?? and how much space above it. if the wire are close to the roof then the tempture will get hot and can affect the conducters.

if inspecter say change to #10 wire maybe he have good reason due the tempture factors .


i work on few commercal bulding and during summer time it do get warm but not super hot. but most important thing is use the common sense to set up properly

merci, marc

 

[charlie]

Re: Temps and MH Lighting

Gentlemen, please. My statement of the inspectors always be correct is normally a true statement. Most inspectors are very knowledgeable and have seen everything, they are running from job to job as fast as they can because they have more to do than can be done in the amount of time they have. When they walk onto a job, they will look at the obvious and if it looks wrong, they will look deeper. I have never seen a job that can't be cut to ribbons but they don't do that.

Some of the inspection is on reputation. If you do your work well, make corrections when asked, and treat the inspector well, your jobs well get a cursory inspection. On the other hand, if you do sloppy work, fight hard about every write up, do not make all of the corrections so repeat trips are required, and blow off the inspector, your jobs will get a tight inspection. Is this fair? Yes, I think so.

Once in a while you will see an inspector that doesn't know what he is looking at. Instead of saying, "Look at that ________.", go over and help him understand the job. He may be green, unknowledgeable about this type of work, or confused about something. Most inspectors will appreciate the help and it will be remembered.

The last thing any inspector wants is to approve an unsafe job that will hurt someone or burn the building. Is that any different than what you want?

Sorry, I get carried away sometimes (maybe I have too many friends in the IAEI). Remember, the inspector is always correct.