The Electrical Contractor Network

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

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!


2017 NEC and Related
2017 NEC
Now Available!

Recent Posts
Parking lot pole light swap....
by gfretwell
10/24/16 08:46 PM
International Wire Colour Codes
by Tjia1981
10/23/16 12:08 PM
Son of Sparky
by HotLine1
10/20/16 07:43 PM
Speaking of Plugmold ...
by gfretwell
10/17/16 02:37 PM
Broken battery charger? Check for cobwebs!
by gfretwell
10/17/16 02:30 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
gfretwell 14
HotLine1 7
ghost307 7
renosteinke 6
Potseal 4
Who's Online
1 registered (cableguy619), 314 Guests and 5 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#3132 - 08/07/01 05:53 AM A/C Causes Interference On Separate Circuit

I set up a separate circuit for a computer in an apartment with 40A service. When the compressor goes on on a 5000 BTU window air conditioner on a separate circuit, the computer screen jiggles a little. While the effect on the monitor is bad enough, it is logical to assume the computer CPU etc. is seeing the same interference which may be an even worse problem.

Is this normal? Is there anything that can be done to prevent it. The computer and peripherals are plugged into a surge suppressor/ battery back-up.

Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#3133 - 08/07/01 10:40 AM Re: A/C Causes Interference On Separate Circuit
resqcapt19 Offline

Registered: 11/10/00
Posts: 2209
Loc: IL
This would not normally be unusual, but I would not expect it on a system with a UPS.

#3134 - 08/07/01 02:32 PM Re: A/C Causes Interference On Separate Circuit
Tom Offline

Registered: 01/01/01
Posts: 1069
Loc: Shinnston, WV USA
How close is the AC to the monitor? Monitor distortion can be caused by a strong magnetic field which leads to the second question. Is all the grounding, all the way back to & including the service done correctly? Grounding mistakes can lead to magnetic fields that would be capable of causing monitor problems.

Good luck
Few things are harder to put up with than the annoyance of a good example.


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