Troubleshooting Circuit Brown Outs

[russgentile]

One of my customers reported when her lawn boy was using an electric mower on the front lawn plugged into exterior GFCI, at one point the mower and interior lights on the same circuit including the LR and DR dimmed momentarily then resumed full power. Separately, she claims the same lights frequently dim briefly in the same rooms for no reason.

Is a brown-out like this indicative of failing branch wiring or breaker for that specific circuit? Or an old mower and old woman? What troubleshooting technique should/can I use?

[ August 18, 2005, 01:19 AM: Message edited by: russgentile ]

 

[macmikeman]

Re: Troubleshooting Circuit Brown Outs

Possible loose neutral at panel, or at the service. Look for corosion at the weatherhead if it is overhead. There also might be a loose connection on the hot side in one of the wirenuts someplace in that branch circuit. This particular problem is sometimes a really good way to get some real troubleshooting experience. How old is the wiring in the house?. It is also possible that there may be a poco connection problem someplace up the line from the service drop connection point. Good luck to you.

 

[allenwayne]

Re: Troubleshooting Circuit Brown Outs

I would start in the middle of the circuit and open it to see what happens,If clears problem is behind you then 1/2 way again.Keep going till you locate where the problem is located.
No that would be the 2nd procrdure,1st start at the panel and go from there.Also what is the amperage rated for this motor.Also calc the lighting load.But I would say there will be a loose connection somewhere

 

[charlie b]

Re: Troubleshooting Circuit Brown Outs

Maybe it's an old house. By current definitions, dining room lights are on "small appliance circuits." You cannot install them on the same circuit as an outdoor GFI receptacle. I am not even sure if you can install LR and DR lights on the same circuit. Perhaps it's time to suggest a modernization of the wiring?

 

[steve66]

Re: Troubleshooting Circuit Brown Outs

Or it could just be the AC kicking on. She probably wouldn't hear it with mower running.


Steve

 

[charlie b]

Re: Troubleshooting Circuit Brown Outs

That's a good thought. The SA circuits might be properly separated from the outdoor circuits. But when the A/C kicks in, the voltage in the entire house will drop for a short while.

 

[haskindm]

Re: Troubleshooting Circuit Brown Outs

Remember that 210-52 (b)(1) Exception 2 of the 1993 code allowed outdoor receptacles to be put on the small appliance circuit. I'm not sure when this was changed, but a house would not need to be very old for this to have been accepted procedure.

 

[benaround]

Re: Troubleshooting Circuit Brown Outs

I'm going to go with the 'Back Stabed' device insallation,if this in fact is one circuit,it gets a lot of use.

I also advocate the 'time to up grade' method, once things start blinking it's not long until they start smoking.

 

[cselectric]

Re: Troubleshooting Circuit Brown Outs

Well, for the problem as described, I'll go out on a limb and say the lawn boy bogged the mower down on something, thus increasing the current draw (an unloaded motor draws less than a fully loaded one.)

As to it happening frequently, I wouldn't start ripping things apart until I asked a bunch of questions in an attempt to find a common thread (Someone mentioned an A/C kicking in, which is a common cause of such problems.

 

[redfish]

Re: Troubleshooting Circuit Brown Outs

Is a brown-out like this indicative of failing branch wiring or breaker for that specific circuit? Or an old mower and old woman? What troubleshooting technique should/can I use?

I would say your "brownout" is the result of: </font>

• <font size="2" face="Verdana, Helvetica, sans-serif">A poor neutral connection, check for an imbalance at the service when the house is under a load. If you have to, plug the mower in and then check voltage at the service or your main. If it is and overhead service, look up on the pole for a corroded or burned neutral, you can also call your local utility and have them come out and check their end.</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">It may be voltage drop due to?under sized service entrance conductors, or feeder conductors. Perhaps more load has been added to this house since the original service installation, and no service upgrades were made.</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">Of course it could also be a poor neutral connection on a device.</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">One thing is for sure, it will be good troubleshooting experience.</font>

<font size="2" face="Verdana, Helvetica, sans-serif">Good luck.