ATSman
ATSman
- Location
- San Francisco Bay Area
- Occupation
- Electrical Engineer/ Electrical Testing & Controls
I had a little lesson in T-shooting at my house recently and would like to share it FWIW.
I was observing electrical problems in 3 rooms of my house for a few month or so.
Master Bedroom
I plug the LED magnetic shop light in the outlet next to the window. I noticed that the green (charged)
LED would change on occasion to red (charging) and in some cases go out. I thought the light had a self-test feature causing this or suspected the multi plug outlet module that plugs into the wall outlet was getting corroded. I took it apart and cleaned it thoroughly but it did not help. I also noticed that the battery charger LED for the Rigid drill I also plug in would loose power at times.
Bedroom (Bath) green rm
The Belkin UPS feeding the AT&T Modem was acting up for a few months (constantly resetting loosing wifi) At first I thought it was the self-test feature mentioned in the manual where the logic would simulate a power fail and switch the load to test the battery. This would happen almost every morn around 7:30AM. The LED would switch from On AC to On Battery and back an forth. I thought maybe the battery was getting old and needed to be replaced. Checked voltage and found 13+VDC. Measured the charger wires but read nothing. I hocked up a wall wart 12DC supply in parallel the battery but did not correct problem.
Bathroom
Using the hair dryer I noticed it would bog down occasionally like it was loosing power and thought it was the fan motor brushes that were getting old. Dryer dates back to early 80’s.
While doing testing of the Belkin UPS on 10-30-16 in the bedroom the power went out completely. I went to kitchen and saw that the house still had power. The UPS power was fed from the bath outlet (to provide a gnd to the bedroom office PC. I took this plug apart suspecting a bad connection but found nothing. I was using a tic-tracer voltage detector which was a big mistake I found out later. I thought their was a break in the wiring from the bath to bedroom so I ran an extension cord from master bedroom to UPS. Turned on hair dryer…..no power at bath outlet. Left dryer on and went to kitchen and in kitchen heard dryer turn on! That was it! The problem had to be an intermittent connection at the feeder breakers in the main power panel in garage! I went to garage and found the 2 breakers that fed the bedroom and bath, turned them off and on several times. Exercising them cleaned the contacts after all these years (36yrs) correcting the problem. When doing PM work on MCCB panels we take contact resistance measurements using a Ductor low resistance ohmmeter if it’s in the scope. Otherwise we just exercise the breakers by opening and closing them.
It has been 3 days and the voltage has been rock solid in all rooms so far. If they show their ugly face then I will have to continue the hunt, look for loose connections and maybe change the breakers.
Just goes to show that no matter how many years in the business T-shooting industrial/ commercial problems you can learn something new every day. The feed back from the client can help or can lead you down the wrong path. But knowing how to connect the symptoms to find the root cause of the problem can help make you find the problem sooner. I just wish I would have connected the dots a lot faster!
I was observing electrical problems in 3 rooms of my house for a few month or so.
Master Bedroom
I plug the LED magnetic shop light in the outlet next to the window. I noticed that the green (charged)
LED would change on occasion to red (charging) and in some cases go out. I thought the light had a self-test feature causing this or suspected the multi plug outlet module that plugs into the wall outlet was getting corroded. I took it apart and cleaned it thoroughly but it did not help. I also noticed that the battery charger LED for the Rigid drill I also plug in would loose power at times.
Bedroom (Bath) green rm
The Belkin UPS feeding the AT&T Modem was acting up for a few months (constantly resetting loosing wifi) At first I thought it was the self-test feature mentioned in the manual where the logic would simulate a power fail and switch the load to test the battery. This would happen almost every morn around 7:30AM. The LED would switch from On AC to On Battery and back an forth. I thought maybe the battery was getting old and needed to be replaced. Checked voltage and found 13+VDC. Measured the charger wires but read nothing. I hocked up a wall wart 12DC supply in parallel the battery but did not correct problem.
Bathroom
Using the hair dryer I noticed it would bog down occasionally like it was loosing power and thought it was the fan motor brushes that were getting old. Dryer dates back to early 80’s.
While doing testing of the Belkin UPS on 10-30-16 in the bedroom the power went out completely. I went to kitchen and saw that the house still had power. The UPS power was fed from the bath outlet (to provide a gnd to the bedroom office PC. I took this plug apart suspecting a bad connection but found nothing. I was using a tic-tracer voltage detector which was a big mistake I found out later. I thought their was a break in the wiring from the bath to bedroom so I ran an extension cord from master bedroom to UPS. Turned on hair dryer…..no power at bath outlet. Left dryer on and went to kitchen and in kitchen heard dryer turn on! That was it! The problem had to be an intermittent connection at the feeder breakers in the main power panel in garage! I went to garage and found the 2 breakers that fed the bedroom and bath, turned them off and on several times. Exercising them cleaned the contacts after all these years (36yrs) correcting the problem. When doing PM work on MCCB panels we take contact resistance measurements using a Ductor low resistance ohmmeter if it’s in the scope. Otherwise we just exercise the breakers by opening and closing them.
It has been 3 days and the voltage has been rock solid in all rooms so far. If they show their ugly face then I will have to continue the hunt, look for loose connections and maybe change the breakers.
Just goes to show that no matter how many years in the business T-shooting industrial/ commercial problems you can learn something new every day. The feed back from the client can help or can lead you down the wrong path. But knowing how to connect the symptoms to find the root cause of the problem can help make you find the problem sooner. I just wish I would have connected the dots a lot faster!
