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What's causing a brown out?

I've noticed that in our new home that when the electric furnace comes on, the lights dim. At present, these are the only two loads on the service.

Here is my setup:

  1. Electric Meter 100 ft. from transformer. This was an existing transformer, so I'm not sure about the load capacity. The utility company seemed to think that it was sufficient for our home.

  1. Electric Meter set on top of a 200 AMP Main Breaker Box with Pass-through lugs.

  2. Service is carried underground to a 200 AMP subpanel on #000 Aluminum conductors over a distance of 300 feet.

  1. Electric Furnace is on a 50 AMP breaker.

When the utility company connected, I was receiving 244 volts at the meter. The subpanel was checked at the same time and was receiving 246 volts, some

300 feet away. Obviously, there was very little, if any, voltage drop.

Is it possible that the main transformer needs to be larger?

Any thoughts?

Randell Tarin

Reply to
Randell Tarin
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Sounds like its very possible you have a loose connection somewhere in the service to your main panel. Could be the meter base or main breaker.

Reply to
Fred

how much does the voltage drop? and what is the current or power of the furnace?

Reply to
TimPerry

You have a long run to the motor which has an appreciable starting current. I suggest that you try to find the starting current inrush of the furnace motor and from this and conductor data guestimate the voltage drop at start. If you are not having problems with other equipment, due to this, it may not be worth the effort to try to fix it. However you should also make sure that your terminal connections are rated for aluminum wire as, if not, this could be a hazard.

Reply to
Don Kelly

Pass-through

Did you measure the voltage when the furnace was on? Did you measure their voltage L-N and L-G during the loading?

Others have suggested that you need to check all of the connections, very true with AL. I check mine every other year.

Have you tried measuring current at the heater?

It is possible that the transformer has a problem. Best to have your house in order before you call them. They will ask you if you have done all of the above. When you say yes, it narrows their focus.

Reply to
SQLit

It can also be the return. I noticed that when things turned on some lights would get brighter and some dimmer. Went out to the box and found that I often had 130 volts on one phase and 110 on the other, then they might switch.

Called the utility company. They traced it to a big aluminum wire out in the neighborhood distribution box (they still use aluminum there).

Reply to
Rich256

...

Unlikely it's the transformer. More likely the feed or a bad connection.

If the transformer is a pole pig, it may have a number stenciled on its side, such as 15, 25, 37.5 etc. This is the transformer rating in kVA. For a resistive load, you can read this as kilowatts. These are long term ratings, the power companies know they're often over the limits over short terms.

Reply to
Michael Moroney

Michael Barrymore maybe?

Reply to
Peter Charles Hood

are you pulling my pisser?

PC Hood

Reply to
Peter Charles Hood

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