FLIR and the Home Inspector

brian john

Senior Member
Location
Leesburg, VA
Many HIs are doing Mold, Radon, EMF and now FLIR testing.
For the record the term would not be FLIR test it is Infrared Test or scanning.

FLIR (Forward Looking Infrared) is a manufacture of IR test equipment.

http://www.flir.com/US/

And for a selfish reason I have argued for years that companies that come into an area unlicensed (no electrical, no state corporation no local contracting license) and perform IR should not be allowed.
 

jxofaltrds

Senior Member
Location
Mike P. Columbus Ohio
Occupation
ESI
For the record the term would not be FLIR test it is Infrared Test or scanning.

FLIR (Forward Looking Infrared) is a manufacture of IR test equipment.

http://www.flir.com/US/

And for a selfish reason I have argued for years that companies that come into an area unlicensed (no electrical, no state corporation no local contracting license) and perform IR should not be allowed.
Correct. I started the title correctly but should have said testing with a Flir camera in my opening statement.
 

jxofaltrds

Senior Member
Location
Mike P. Columbus Ohio
Occupation
ESI
In general terms, black is no more emissive than white. That being said, if you have black PVC jacketed wire and white nylon jacketed wire, then you will have differences. The color in the visible spectrum has little to do with emissivity. Its the material and surface preparation.

When I get back to the shop on Monday, ill make some pictures. Any requests? Ill do 12ga black, red, white and green THHN, all at the same measured temperature.
Suprise us!
 

kwired

Electron manager
Location
NE Nebraska
The problem with using thermal imaging devices is knowing how to read what you see and know what it means. In the case of a dwelling what are the chances of catching all the circuits with significant enough load to heat them up if there is a problem? Outside of HVAC loads most breakers in a dwelling will be relatively cool most of the time, simply because they are not loaded constantly like they may be in a commercial or industrial setting. If a HI showed me a hot breaker in a dwelling panel and I find it to be the breaker for the AC and it was middle of summer when image was taken I will not be too suprised in most cases in fact I will expect that breaker to be hotter than any others in most cases, it is about the only load in most dwellings that actually has demand for long periods of time. Refrigerators and freezers may have long term demand but not necessarily at a level near the upper range of the overcurrent device either. 4 amp refrigerator is not going to heat a 20 amp breaker to same amount as a 17 amp AC will heat a 30 amp breaker, if in good condition.
 

ramsy

Owner/Operator
Location
LA basin, CA
Occupation
Service Electrician 2017 NEC
..one job I did involved getting the AHJ to a house that an HI {inspected}.
If only more home owners knew how took get the AHJ involved. If the right buyer can miss property defects and pay cash, mortgage insurance is avoidable, and no record exists of previous failed HI inspections.
 

ELA

Senior Member
If it was just from the circuit loading, I would expect that the temperature of the conductor would be more uniform. There is a hot spot at the point of termination and I would expect to find a poor connection based on the picture.
Don,
We had an Industrial situation where a customers Inspector told them a breaker was running too hot and they sent a FLIR report. From the picture alone it looked like a real issue. Colors can be very deceiving, in this report the hot spot was "white" hot.
Unfortunately this was from about 10 years ago at a different job position so I no longer have access to the actual numbers or I would relate them.

We went out to the field and inspected, measured currents etc. Nothing was wrong. This breaker was loaded more heavily than others in the same panel but within ratings.

Once back in the lab I ran the same breaker type under normal load current and measured the temperature of the thermal element with a thermocouple. It was very, very hot ( wish I still had that report for actual numbers). Taking a FLIR of that test breaker looked just like the field report and nothing was of concern.

They were showing the very hot spot that was actually the thermal element in the breaker. This very hot element has a good thermal conduction path to the load wire termination. You will see the heat from the thermal overload travel some distance down the wire. In this case it was not about the wire heating directly due to load current but instead from the thermal element outward for a short distance. Looked very much like a loose terminal might but it was not a loose terminal.

I am not saying this case is the same. I am just saying more information is required than just a FLIR picture with relatively low temperatures being shown.
Again I wish I had access to the data. Going strictly from a very poor memory the picture shown here is much cooler than we measured.
 

kwired

Electron manager
Location
NE Nebraska
This very hot element has a good thermal conduction path to the load wire termination. You will see the heat from the thermal overload travel some distance down the wire. In this case it was not about the wire heating directly due to load current but instead from the thermal element outward for a short distance. Looked very much like a loose terminal might but it was not a loose terminal.
This is exactly why when we are determining what size of a conductor to use we must multiply continuous loads by 125%, with the exception being an overcurrent device listed for operation at 100% of its rating. Those 100% devices do not depend on the conductor to be a heat sink. Circuit breakers that are 100% rated are likely to be electronic instead of thermally operated and will not have that kind of heating within.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Don,
We had an Industrial situation where a customers Inspector told them a breaker was running too hot and they sent a FLIR report. From the picture alone it looked like a real issue. Colors can be very deceiving, in this report the hot spot was "white" hot.
Unfortunately this was from about 10 years ago at a different job position so I no longer have access to the actual numbers or I would relate them.

We went out to the field and inspected, measured currents etc. Nothing was wrong. This breaker was loaded more heavily than others in the same panel but within ratings.

Once back in the lab I ran the same breaker type under normal load current and measured the temperature of the thermal element with a thermocouple. It was very, very hot ( wish I still had that report for actual numbers). Taking a FLIR of that test breaker looked just like the field report and nothing was of concern.

They were showing the very hot spot that was actually the thermal element in the breaker. This very hot element has a good thermal conduction path to the load wire termination. You will see the heat from the thermal overload travel some distance down the wire. In this case it was not about the wire heating directly due to load current but instead from the thermal element outward for a short distance. Looked very much like a loose terminal might but it was not a loose terminal.

I am not saying this case is the same. I am just saying more information is required than just a FLIR picture with relatively low temperatures being shown.
Again I wish I had access to the data. Going strictly from a very poor memory the picture shown here is much cooler than we measured.
That's neat, it confirms the requirements of 210.19(A)(1). :)
 

brian john

Senior Member
Location
Leesburg, VA
My thermographers are all trained and have anywhere from 5-34 years experience. I/we do not just turn loose an electrician with an IR camera. They are trained and work with an experience thermographer until they are comfortable inspecting, interpreting all data, doing the required math to determine if a particular piece of equipment based on the type of equipment being scanned, the load, the ambient and the temperature of the discrepancy. In addition the reports are reviewed by two seperate men in the office, a thermographer and task master (my partner) looking for possible errors, spelling, IR, NEC, ETC.........


Doing a point and shoot in my opinion is wasting your time and the customers. But that seems to be where the market is heading.
 

kwired

Electron manager
Location
NE Nebraska
Doing a point and shoot in my opinion is wasting your time and the customers. But that seems to be where the market is heading.
Especially when done like in the OP. We have a panel with one breaker operating at a higher temp than the others - a little look at into why is the next step and not just assuming it has a problem. It may be the only breaker in the panel at the time image was taken that had any significant load on it, but otherwise had no problems.
 
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