Latest Discussions : Electrical & Lighting

02:53AM | 08/03/00

Member Since: 06/13/00
3 lifetime posts

Dimming lights

I have seen posts on this and other boards that talk about lights in the house dimming momentarily when the furnace blower or
other large appliance comes on.

The responses have been that you either have 1) an unbalanced load or 2) a loose neutral connection.

So here's my question(s).
1) Re: unbalanced load. Let's say that the only electric usage in the house is a couple of table lamps on one branch circuit and the
furnace blower (gas furnace so only current draw is the blower) comes on. Won't this ALWAYS create an unbalanced load? The
starting draw for the furnace blower is going to be WAY more than the two lamps. I guess I don't understand what is meant by
"unbalanced load". What is is and how can I check for it and what is the solution????

2) Re: loose neutral connection. Given the table lamps and furnace blower scenario, would I be looking for loose neutral
connections only on those two circuits and only where current is being used? Meaning, loose connections at the two lamp outlets
or where this circuit attaches to the neutral bar at the panel or at the neutral connection to the furnace blower or where that circuit
connects to the neutral bar at the panel or the MAIN neutral connection. That is to say, it wouldn't do any good to go check the
neutral connection for the bathroom light in this example, right?

Bottom line, can anyone give more troubleshooting hints than "unbalanced load or loose neutral"??

rpxlpx

05:20AM | 10/03/00

Member Since: 03/13/00
1674 lifetime posts

I believe "unbalanced load" does not literally mean unequal usage of both/all circuits. It simply means that one circuit has too much load, regardless of the other circuits.
You can "balance" that by moving some of the load from the overloaded circuit to another one that is not so heavily used.
As to your "neutral" question: yes it makes sense to look only for a neutral problem in the places where the neutral for that circuit is found.

[This message has been edited by rpxlpx (edited October 03, 2000).]

ElectrcBil

07:30AM | 10/06/00

Member Since: 07/21/00
76 lifetime posts

When a motor load starts on a circuit it draws considerably more current at start up than when it is running at full speed. This is because of the torque required to start the load of the motor spinning. The problem you are describing is very common in older houses were a lot of new appliances have been added to a service that was not designed for that much of a load. I know the problem can be annoying but often cannot be changed without a lot of expense. Call a qualified electrician out and have them give you an idea of what can be done.