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craigflor · Joined: 27 Oct 2004 Posts: 3

Hi. I live in a trailer and have had a few lightbulbs blow recently and the lights dim every now and then. I started to check the voltage in my outlets and was surprised to find a large variation throughout the trailer. In a couple outlets my multimeter read as low as 96VAC, while in other outlets it read as high as 156VAC. The remaining outlets varied between those. I checked the outlets all again shortly after the first time and have found that the amount of voltage read at each outlet often changes over time. I understand that there will be some variation, but isn't this quite extreme? My multimeter is really cheap, but I wouldn't think that it would be that far off. Should I call an electrician out right away? I'm a little worried about possible damage to my computer, TV, DVD player, etc.

b · Posted: Thu Oct 28, 2004 3:36 am Post subject:

Found this on monster...

The power that comes into your home, and then out of your wall outlet, is constantly changing, and usually for the worse. There are many reasons for this.

Outside your home, your utility company’s electrical grid is reacting to constant changes in consumer demand. The higher the common demand in your community – early evening hours are typically the busiest – the less power coming into your home. Typical homes fluctuate between 80 and 140 volts

Once inside your home, the effect is made even worse. Today’s households typically include dozens of power-sapping components, from appliances to computers, not to mention home theater gear itself. Many of today’s household appliances draw more power (some over 1500 watts) than your house wiring was originally designed to support. These demands can result in even more voltage sags (a dip below the standard value of 120 volts) to your wall outlets.

There are voltage regulators available. Hope this helps.
b

craigflor · Joined: 27 Oct 2004 Posts: 3

Thanks for the tip. I'll have to look into a voltage regulator.

I started checking voltages in the breaker box. Of the two phases that come into the trailer, one is normally at around 126V, while the other is normally around 120V. Whenever a load is applied to one phase it lowers, while the other raises a proportional amount. For example, I plugged a 1500W heater into an outlet on one phase and it dropped 8V, causing the other phase to rise 8V. I haven't seen any extremes over a 10V variation lately. I assume that too many consumers must be on the same transformer, though.

My question now is this: It seems that the voltage into the trailer is being regulated near 240V (somewhere around the transformer I assume), but is it normal that only this high voltage is regulated, regardless of the voltage on each phase? I mean, shouldn't each phase be regulated independently at around 120V, or is that just not how it's done?

I have one more concern for now, too. I isolated every circuit to find out exactly which outlets and switches were on each circuit. As I was looking at the wiring in the box, I noticed that one of the circuits had a 20amp breaker but only 14 guage wire. As I understand, 14 guage wire is only acceptable for up to 15amps, correct? I haven't checked each outlet to see if it is 14 guage all the way through, but would it necessarily matter if 12 guage was wired to 14 guage somewhere in the circuit? My main concern should be with the breaker, shouldn't it? Should I just replace the breaker with a 15amp one, or is there something else to be done?

Thanks for your help.

b · Posted: Mon Nov 01, 2004 4:42 pm Post subject:

hi craig
as far as the regulation at the transformer... that is a high power supply question and i do not know. i am an inside journeyman electrician. your electrical provider would be a better one to ask. they have electrical engineers on staff as site planners.
the 14 awg on the 20 amp circuit is a problem though. YES change the breaker to a 15A as that is all the wire is rated for. Too much current on a smaller wire will melt insulation and create havoc, possible fire. If the circuit is supplied with a 14 wire it does not matter if there is 12 guage somewhere else in the circuit. the 12 will handle the 15A no prob, but the 14 is not rated for 20A. You are right in wanting to change out the breaker for the correct size.
b

craigflor · Joined: 27 Oct 2004 Posts: 3

b,
Thanks for the verification. I really appreciate your help and the service you guys are providing here. I'll change the breaker and also contact the power company. Thanks again.
Craig