Latest Discussions : Electrical & Lighting


06:31PM | 11/29/05
Member Since: 11/28/05
1 lifetime posts
Have a 15 amp circuit (with 14 gauge wire of course) which has 2 bedrooms on it now. There are currently 11 outlet boxes, and 2 ceiling fans each with one 60 bulb in them. A contractor adding a sunroom on that will have 2 ceiling fans, one outlet box and one light fixture wants to put that room on the same 15 amp circuit. Will this be ok? or is it too much. currently there are 2 computers, and 2 TVs on this circuit along with a fax machine.

2nd problem: (same circuit) when the fax machine is running and not in sleep mode, the lights flicker in these 2 rooms. I have test it with everything unplugged and one of the ceiling lights on also; I turn fax on and get the flickering until it goes into sleep mode....this is with NOTHING else on or plugged in even. It also does same thing with clothes iron, or hair dryer. Is this a problem? It certainly is annoying. It seems if there is just one device running with one light on, it should not do this....I really need help here! What could be the problem????


Tom O

02:43PM | 11/30/05
Member Since: 09/17/02
476 lifetime posts
Sure hope you're not related to Chemical Ali.

Anyway, a 15 amp general purpose lighting circuit can serve 600 square feet of your house. Measure up the bedrooms & add in the additional area for the sunroom & that will tell the tale.

Personally, I'd run a new circuit for the computers & fax machine.

The fax machine could have a thermal element that is cycling & causing the flickering lights. Laser printers are notorious for this type of problem & matbe your fax machine is doing the same thing.

The other loads you mentioned that cause the problem are all fairly hefty & it would be normal for lights to dim with a large load. If you want sdme peace of mind, hire an electrician. He can determine if this is just normal voltage drop or signs of a loose connection.



08:22AM | 12/02/05
Member Since: 09/17/02
524 lifetime posts
Empty receptacles don't use any power. It all depends on what you plug in them. If you plug in a heater then one receptacle is enough.

The flickering light is probably do to the fax machine fuser unit turning on and off. The fuser unit is a heater that melts the dry toner onto the paper.


06:45AM | 12/04/05
Member Since: 01/30/05
360 lifetime posts
Or if you have an old-style fax machine the heating unit that activates the thermal paper.

When the motors (that drive the paper through the printer or fax machine) are first running they too draw more power.

When the cooling fan inside of your computer, and/or the "chip fan" activates your computer will also be drawing more "power".

When motor loads don't have sufficient voltage available, they actually draw more power to compensate and tend to "heat things up" more as well.

15 Amps x 120 volts = watts or va (volt amps). That would be the ideal maximum that you could have available for use. Voltage drops due to a host of issues would further reduce your available "power". That useful "watts law" calculation in comparison with the "ratings" on the items you're planning on having "in use" on this circuit will help you in your determinations.

There may be some restrictions presently in effect regards to electrical codes and other building codes in your jurisdiction with regards to combining a branch circuit that supplies sleeping room lighting and a "sun room" depending on if this "sun room" is considered a damp location, regards to what may or may not be present in your existing wiring. You may also want to keep in mind forthcoming recommendandations/requirements to have supplies to sleeping rooms (120 v) being AFCI protected.

Incandescent light bulbs dimming are usually the first indicator to a DIYer/homeowner that they are experiencing a "power shortage".

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