ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals

Topic Options
Rate This Topic
#11140 - 07/01/02 02:26 PM 123.9 VAC drops to 122.4 ???
strainsa Offline
Junior Member
Registered: 08/18/01
Posts: 3
After installing a new outside AC compressor the voltage at any outlet drops from 123.9 to 122.4 whenever the AC starts. This causes a momentary flicker in the household lights about 80% of the time. The AC company has installed a hard start capacitor with no change in the flicker. I had the utility company come out and they checked the voltage across the meter and saw the same thing. They said it is OK and within their specifications. Are they giving me a straight answer?
Top
Work Gear for Electricians and the Trades
#11141 - 07/01/02 04:33 PM Re: 123.9 VAC drops to 122.4 ???
Ron Offline
Member
Registered: 03/13/02
Posts: 582
Loc: White Plains, NY
I believe they can give you plus or minus 10% of nominal. So, If nominal is 120V then the math looks like 108-132V. How big is the service, how bid is the compressor?
It might also be an undersized service or service conductors. Have you completed a demand calc for this new load with the existing arrangement?
_________________________
Ron
Top
#11142 - 07/01/02 08:14 PM Re: 123.9 VAC drops to 122.4 ???
Bjarney Offline
Moderator
Registered: 04/10/02
Posts: 2527
Loc: West-Southern Inner-Northeast ...
Sounds like superb voltage regulation. ANSI limits are ~110-127, and these numbers are in most utility and appliance manufacturer boilerplate.

Incandescent lamp flicker can be very difficult to subvert, for the human eye is very sensitive to it. Looks like everything is up to snuff and then some.
Top
#11143 - 07/02/02 02:58 AM Re: 123.9 VAC drops to 122.4 ???
Trainwire Offline
Member
Registered: 03/15/02
Posts: 360
Loc: Strasburg,PA,USA
Join the club, Ihave the same problem with My AC. When I had the 200 amp panel, meterbase and service entrance put in, the poco didn't bother to change the drop off the pole, so I have 2awg drops feeding a 4/0 service entrance, in the summer time when the other 2 houses on the transformer are running their ac too, I get a very pronounced flicker.
This is the ac's third season, so far so good.

Trainwire
Top

Member Spotlight
Member Since: 01/22/05
Posts: 5316
New in the Gallery:
SE cable question
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box


Who's Online
0 registered (), 54 Guests and 8 Spiders online.
Key: Admin, Global Mod, Mod
 
New in the Gallery:
SE cable question
 
Top Posters (30 Days)
Admin 51
HotLine1 43
gfretwell 17
Trumpy 16
Ruben Rocha 13
 
Newest Members
clee512, Jdscott2005, FAIZAN, Regitest2, sureshazhagai

ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals