ptonsparky
Tom
- Occupation
- EC - retired
What brand was it?
Brand New Construction Lights Dim in a few places with Vacuum load
- Thread starter juant1971
- Start date
- Status
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
200123-2230 EST
To add to my previous comment in post #5.
At the same receptacle I did some quantitative measurements with a Kill-A-Watt EZ..
First with the same vacuum sweeper ---
0.9 V change from the sweeper load.
3.3 A load current.
390 W load power.
390 VA.
0.97 PF.
Second I used my 1500 W heater as the load ---
3,5 V change from the heater load.
12.2 A load current.
1450 W load power.
1450 VA.
1.0 PF.
Tonight a test at the main panel using the 1500 W heater at a receptacle with 1 foot of wire to the breaker, voltage measured at the main panel input wires ---
0.8 V drop change from heater load.
0.4 V increase change from heater load.
Note that on a 120 V single phase load on a center tapped secondary that about 1/2 of the loop voltage drop change is on the neutral and 1/2 on the hot conductor.
.
.
To add to my previous comment in post #5.
At the same receptacle I did some quantitative measurements with a Kill-A-Watt EZ..
First with the same vacuum sweeper ---
0.9 V change from the sweeper load.
3.3 A load current.
390 W load power.
390 VA.
0.97 PF.
Second I used my 1500 W heater as the load ---
3,5 V change from the heater load.
12.2 A load current.
1450 W load power.
1450 VA.
1.0 PF.
Tonight a test at the main panel using the 1500 W heater at a receptacle with 1 foot of wire to the breaker, voltage measured at the main panel input wires ---
0.8 V drop change from heater load.
0.4 V increase change from heater load.
Note that on a 120 V single phase load on a center tapped secondary that about 1/2 of the loop voltage drop change is on the neutral and 1/2 on the hot conductor.
.
.
Last edited:
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
As we've discussed in other threads, this is why I wire like Kwired does.
gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
200124-1649 EST
I my previous post I failed to mention that I did not perceive flicker in the incandescent bulb in the voltage change measurement at the main panel ftrom the 12 A heater load.
Suppose the voltage changes at the main panel were much greater than I measured. For example --- suppose a 2.2 V drop in voltage across the heater was observed when the heater was turned on, and with a voltage change increase of 1.4 V for the unloaded side. Now the ratio is 1.57 instead of 2.
Also it would be useful to be looking at the hot line to hot line voltage change between no heater and heater.
At this time we have insufficient information to judge whether there is a high resistancer neutral and/or or hot wire power company problem.
If there are no major voltage changes at the input to the main panel, the above tests will tell us, then the high trsistancre is in the panel or after.
.
I my previous post I failed to mention that I did not perceive flicker in the incandescent bulb in the voltage change measurement at the main panel ftrom the 12 A heater load.
Suppose the voltage changes at the main panel were much greater than I measured. For example --- suppose a 2.2 V drop in voltage across the heater was observed when the heater was turned on, and with a voltage change increase of 1.4 V for the unloaded side. Now the ratio is 1.57 instead of 2.
Also it would be useful to be looking at the hot line to hot line voltage change between no heater and heater.
At this time we have insufficient information to judge whether there is a high resistancer neutral and/or or hot wire power company problem.
If there are no major voltage changes at the input to the main panel, the above tests will tell us, then the high trsistancre is in the panel or after.
.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
If it was actually arcing it might trip, lets just say that is a condition it is supposed to trip for. "Glowing connection" is a resistance load just like a heater.
Those arcing connections burn themselves out, especially with only 120 supply volts and IMO are not as likely to start a fire as a glowing connection, which AFCI's don't detect.
- Status