recessed lights dimming & flickering
- Thread starter eamon
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brian john
Senior Member
- Location
- Leesburg, VA
There are several issues here,
Possible loose neutral which needs attention IMMEDATLY. This can be from the transformer to your branch circuits.
Flicker which can be something you are doingg (motors starting or possible a neighbor issue, depending on the utility distribution in your area.
Light flicker (dimming and restoration of light to near preflicker level) of lights from motor inrush) is a byproduct of several factors and generally is difficult to over come.
AC motor loads (in particular compressors) but all motor loads have inrush currents. These inrush currents result in voltage drop in the branch circuit, panel bus, service laterals, utility transformer and possibility the utility HV feeders.
Flicker is in addition user dependent; some people are more susceptible to flicker. For some reason flicker seems to bother women more that men (based upon personal experience).
A Voltage Drop (VD) as little as 3 volts on a nominal 120 VAC system is noticeable (by me), 2.5% VD.
We have had cases were the VD was all a byproduct of primarily single phase 120 VAC loads, in these cases we were able to put the lighting on L1 and all the motor loads on L2, the HVAC compressors were something the homeowner had to live with. This minimizes the flicker.
To test for this VD and resulting flicker to determine the source of the inrush, use a min max amp clamp and min max multimeter at the main service watch the lights(it may take two workers) and correlate to the meters.
Possible loose neutral which needs attention IMMEDATLY. This can be from the transformer to your branch circuits.
Flicker which can be something you are doingg (motors starting or possible a neighbor issue, depending on the utility distribution in your area.
Light flicker (dimming and restoration of light to near preflicker level) of lights from motor inrush) is a byproduct of several factors and generally is difficult to over come.
AC motor loads (in particular compressors) but all motor loads have inrush currents. These inrush currents result in voltage drop in the branch circuit, panel bus, service laterals, utility transformer and possibility the utility HV feeders.
Flicker is in addition user dependent; some people are more susceptible to flicker. For some reason flicker seems to bother women more that men (based upon personal experience).
A Voltage Drop (VD) as little as 3 volts on a nominal 120 VAC system is noticeable (by me), 2.5% VD.
We have had cases were the VD was all a byproduct of primarily single phase 120 VAC loads, in these cases we were able to put the lighting on L1 and all the motor loads on L2, the HVAC compressors were something the homeowner had to live with. This minimizes the flicker.
To test for this VD and resulting flicker to determine the source of the inrush, use a min max amp clamp and min max multimeter at the main service watch the lights(it may take two workers) and correlate to the meters.
eljefetaco
Member
- Location
- Fanwood, NJ
I agree with above statement. If you have 400 amp res service and use two 200a main lug panels would putting the hvac compressors in one panel and lights in another solve issue. Just a thought
durraniguy
Member
Loose connections
Loose connections
There is a loose connection somewhere, in the washer ckt. In the lighting ckt (especially if they share the same neutral -or maybe in the client's brain. I have multiple had call backs on a client who was the only witness to such flickering.
Loose connections
There is a loose connection somewhere, in the washer ckt. In the lighting ckt (especially if they share the same neutral -or maybe in the client's brain. I have multiple had call backs on a client who was the only witness to such flickering.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Simplest way to start is by measuring the voltage from each line to the neutral during the flicker.
If one line voltage remains steady, and the other drops, there's an issue on that line.
If one voltage rises, and the other drops, there's an issue in the neutral.
If both voltages remain steady, the washing machine needs its own circuit.
If one line voltage remains steady, and the other drops, there's an issue on that line.
If one voltage rises, and the other drops, there's an issue in the neutral.
If both voltages remain steady, the washing machine needs its own circuit.
B4T
Senior Member
- Location
- Long Island, N.Y.
Also look on the street where the transformer is located and how many houses are past where you are tied in.
Check with a neighbor and see if they are having the same issues.
Check with a neighbor and see if they are having the same issues.
brian john
Senior Member
- Location
- Leesburg, VA
I have looked at countless flicker issues and seldom is the issue a loose connection, I am not saying not to look for this issue but typically it is much more than a loose connection.
Simple trouble shooting will prove out the source of the flicker.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Yes, and I forgot to mention I was talking about measuring at the panel in my last post.
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