Any cheap heat meters ?

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brian john

brian john

Senior Member
Location
Leesburg, VA
Jim W in Tampa said:
Having small problem with my own residential service. Triped 200 main twice in last 2 weeks. Both times were Saturday nights with heavy loads but far under 200 maybe not even 100 amps. Breaker (SQ D) was hot to touch. Tightened wires and they did need it. POCO dropping line in afternoon to check there lugs. Would like to own a low end meter to help in future . Any suggestions and rough price.
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All you need os to do a FALL OF POTENTIAL TEST FOP, what was done prior to hand held IR thermometers.
 
480sparky

480sparky

Senior Member
Location
Iowegia
nakulak said:
besides your hand, good milk chocolate also makes good thermometer
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I actully fried an egg on a transformer once to demonstrate to the distibutor how hot it was getting.
smiley_cookingmishap.gif


A few week later, I bought a Raytek MX4+.
 
Jim W in Tampa

Jim W in Tampa

Senior Member
Location
Tampa Florida
George Stolz said:
Can you elaborate?

When I think of FOP, I think of testing a grounding electrode system; how would it work for testing bad connections?
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What he is after is measuring the voltage drop from point to point thru the service. Depending on amount of amps going thru it the service you would see a voltage drop perhaps across the breaker from the in to the out. Very slow way to go about it but in a pinch could find problem.

We had and still do have a problem that one line on this 300 foot drop comes up 5 volts lower than the other. This could be result of the 4 other houses on the same transformer that are unbalanced.
 
T

templdl

Senior Member
Location
Wisconsin
I have a Fluke 80PK-IR Infrared Temperature Probe is a non-contact temperature probe that has since been discontinued. It has been invaluable in reading temperatures. One application was in trouble shooting a 2P main breaker that had a bad contact which showed up much hotter than the other. I simply plug this thing into my FLUKE 26 and the temperature reads on on my display.

http://us.fluke.com/usen/Products/p...e=FlukeUnitedStates&cs_id=8574(FlukeProducts)
 
G

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
100127-1427 EST

Jim W in Tampa:

I did a quick check on your voltage drop at 175 A. Looks about correct for the wire length.

Aluminum is 1.65 times copper. 1000 ft copper #2 is 0.156 ohms. Thus, for a loop length of 600 ft the resistance should be about 0.6*1.65*0.156 = 0.154 ohms at 20 deg C. Your test time would not cause an appreciable increase in wire temperature. 34 V drop at 175 A = 0.194 ohms. My pole transformer has an impedance somewhat under 0.06 ohms.

.
 
Jim W in Tampa

Jim W in Tampa

Senior Member
Location
Tampa Florida
gar said:
100127-1427 EST

Jim W in Tampa:

I did a quick check on your voltage drop at 175 A. Looks about correct for the wire length.

Aluminum is 1.65 times copper. 1000 ft copper #2 is 0.156 ohms. Thus, for a loop length of 600 ft the resistance should be about 0.6*1.65*0.156 = 0.154 ohms at 20 deg C. Your test time would not cause an appreciable increase in wire temperature. 34 V drop at 175 A = 0.194 ohms. My pole transformer has an impedance somewhat under 0.06 ohms.

.
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I was not really concerned about there wire getting hot. My concern is the main breaker getting hot and triping. A normal load with all my heaters running and other good stuff is about 20 kw in heat assuming all are running non stop , Air conditioner in main house,other loads are harder to add but include hot tub , 4 crock pots on warm, freezer,2 frigs, lights,water heater,water pump, DJ sound system. Rough guess puts me at about 30 kw and some peaks.
We have evaluated our problem and will drop 11 kw off of this load by going to propayne for part of the heat. It is very likely that my 200 amp main hit some unwanted peaks. Forgot to ask the POCO just how large there portable load is.
 
G

gar

Senior Member
Location
Ann Arbor, Michigan
Occupation
EE
100127-1820 EST

Jim:

The point of my calculation was that the voltage drop you measured was about what could be expected for your wire length.

Prior to your correcting the loose joints you no doubt had a small additional voltage drop. If the voltage drop across the main breaker and its connections was even 1 V, then with your 175 A load on both sides of the main there would be 350 W dissipation. That would be quite hot. Direct measurement of the voltage drops in the main panel would be the best troubleshooting method. But IR is a nice quick way to look for hot spots.

34 V at 175 A is 6000 W dissipation in your service wires and some in the transformer. Somewhat less than 6000 in the wires because of the reactance in the transformer. Just the wires alone maybe 175^2*0.154 = 4716 W.

As an aside using my son's Fluke 62 IR thermometer most spots in my basement are between 66 and 69 deg. Same all over the main panel which is in the basement and near the furnaces and water entry. The outside of my gas water heater is 77 deg. The furnace flue is 220 as it leaves the furnace when heating. The hot air duct is about 88 and drops to 69 during the off part of the cycle. Obviously internal temperatures are higher. It is amazing how well this Fluke works on all different surfaces. My refrigerator freezer reads -10 and 33 in the other part. My solid core front door is 54 and the plate glass beside it 44. My windows with storms are about 55. The outside temperature is about 20. I would recommend this little meter.

.
 
ichimo23

ichimo23

Member
Location
Phoenix , Arizona
normal temp ranges for breakers?

normal temp ranges for breakers?

I've thought about investing in an IR thermometer, and was wondering if there is a good source for information regarding 'normal' operating temperature ranges. Nobody at the (small) company I work for uses a thermometer. I've only used the 'touch test', then put a amp meter on the hot breaker to check the load. I assume temperature would vary quite a bit relative to load, breaker size etc? For those that use them, how do you most effectively utlize an IR thermometer?
 
mivey

mivey

Senior Member
gar said:
100127-1820 EST

Jim:

The point of my calculation was that the voltage drop you measured was about what could be expected for your wire length.

Prior to your correcting the loose joints you no doubt had a small additional voltage drop. If the voltage drop across the main breaker and its connections was even 1 V, then with your 175 A load on both sides of the main there would be 350 W dissipation. That would be quite hot. Direct measurement of the voltage drops in the main panel would be the best troubleshooting method. But IR is a nice quick way to look for hot spots.

34 V at 175 A is 6000 W dissipation in your service wires and some in the transformer. Somewhat less than 6000 in the wires because of the reactance in the transformer. Just the wires alone maybe 175^2*0.154 = 4716 W.

As an aside using my son's Fluke 62 IR thermometer most spots in my basement are between 66 and 69 deg. Same all over the main panel which is in the basement and near the furnaces and water entry. The outside of my gas water heater is 77 deg. The furnace flue is 220 as it leaves the furnace when heating. The hot air duct is about 88 and drops to 69 during the off part of the cycle. Obviously internal temperatures are higher. It is amazing how well this Fluke works on all different surfaces. My refrigerator freezer reads -10 and 33 in the other part. My solid core front door is 54 and the plate glass beside it 44. My windows with storms are about 55. The outside temperature is about 20. I would recommend this little meter.

.
Click to expand...
How are compensating for emissivity or does it matter?
 
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