Amprobe problem.

Geo-TH,In

Well-known Member
I have 2 amprobes that have served me well. One is an old school analog, no battery. The other is digital, replaced 9v battery with a new one. Neither one would work yesterday. They were in a cold truck. So on the way home, I stopped off at HF, bought their best digital probe. When I got home, I found my old digital probe works as it should. On the way home, it was in the warm truck cab.

I'm scratching my head, is it possible the cold probes didn't want to work? My old probes have served me well. Never once had any problems using them measuring current inside a load center.

Yes, I know you only put the probe around one wire current carrying wire at a time.

Going back today and see what my problem is. The probes better work.

Tenants electric bill is excessive. No way they can use that many KW-hrs even if all electric heater ran 24/7/30. Either electric meter is defective or there is a problem with grinder pump, which belongs to city, sticking on. Going to put a current sensor on grinder wire and see how many hours it runs and see if it stucks in the on position. Something is very wrong.
 
You should be able to look at the owners manual on the amp probe, either the original or online, it will tell the temperature limits for proper operation.
 
Hello Geo-TH,In,

That should be easy to duplicate. Cold sounds like the culprit, together with possibly battery connections? Put the meter in the same conditions with the new battery, and see what happens.
Those injection pumps have a float that controls the on and off. Paper gets around the float and it sinks. Should be able to hear it running if that is the case,

Guido.
 

Remember also batteries are lower in cold weather. However if no current flowing neither one will work.
 
Occasionally I have to take an appropriate tool and bend the contacts just a bit to make a better connection to the batteries.
 
You didn't say how cold, but many digital displays will not work if weather gets real cold, plus as has been mentioned battery voltage drops when the battery is very cold.
 
Geo,

You doing submetering there? First mention I've ever seen of submetering outside NYC. I know it's being done but don't here of it much. I work for Bay City Metering Co., Inc. We're in NYC. Have been in the submetering biz for 35 years, we read 40,000 meters per month. What kind of kwhrs did the tenant get in a month?

Richard
 
If those are true rms meters, it's quite possible they won't work in extreme cold. Most TRMS meters use some kind of thermal device to sense rms current.

I doubt you'll find anything wrong with the meter. Nothing tenants do surprises me anymore. I couldn't figure out why our tenants in Pontiac always run up exorbitant water bills. (We pay the bill and tack it onto their rent.) I eventually figured out the root problem was the washer and dryer (which we provide). They were running a landromat for half the neighborhood!
 
Wanted to use my DVOM meter a couple weeks ago, was dead, replaced batt., still dead, took it in the house a couple hours and it came to life. It's a Blue Point so it's not the cheapest one on earth.
 
I'm not in the meter reading business. Tenant has baseboard heat, 8000 w total. So 8000 x 24 x 30 = 5760 kw-hrs if the heaters ran 24/7/30, which there is no way. Bill showed over 6800 kw-hrs. Tenant called Duke, filed a complaint. The sub meter reader will most likely get fired. He has been caught curb reading too many times.

I installed a device on the grinder pump, it grinds the sewage and pumps it to town, to monitor the hours it runs a day. There was an issue with it last month. So far so good, think that problem has been solved. Probes worked today as they should. I now have 3 probes, they all read very closely when measuring the same current. I have no standard to go buy. I feel they are accurate enough for my purposes.

Lesson learned, keep your meters warn. I put the new one under passenger’s seat where heat will blow on it. The old analog probe is in the tool box with 2 other volt meters, one digital and one analog. I might add once before I had a bad experience with a digital tester. It was when I was having a physical.
 
Guys, the analog probe uses no battery. It didn't want to work either. I checked battery voltage, even replaced it with a new one. All work fine when they are warmed up. Keeping the new one in cab to stay warm. I feel the cold had something to do with them not working. Could have gotten condensation inside meters when they came in to a warm room.

Once before I had a problem with an EVOM not working when I measured 240 v going to a water heater. Meter lied, zero volts. I new better, I could hear the water heater making a sound. Power was on. DON'T BET YOUR LIFE ON YOUR METERS, YOU COULD LOSE.
 

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