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
Today at 08:46 PM
International Wire Colour Codes
by Tjia1981
Yesterday at 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
0 registered (), 311 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#6910 - 01/14/02 01:28 PM Power Spike on A Phase
C.Urch Offline

Registered: 05/23/01
Posts: 36
Loc: Kill Devil Hills, NC USA
Did a service call today at a municipal building where a breaker powering some receptacles (copy machine, computer, fax, etc.) trips rhyme or reason ever few days or so. One phase in the subpanel reads a steady 25 amps while the other spikes every 3 to 10 seconds between 15 and 40 amps. The only circuits in the panel are lighting and receptacle loads. Does anyone have a clue as to what might be causing this?

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....

#6911 - 01/14/02 01:41 PM Re: Power Spike on A Phase
Tom Offline

Registered: 01/01/01
Posts: 1069
Loc: Shinnston, WV USA
Get that no good #$@@@*& copier on its own circuit. There is a heater in it that is cycling & them babies can draw some serious power for a split second.

Other than that, your SWAG is as good as mine.

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

#6912 - 01/14/02 01:52 PM Re: Power Spike on A Phase

Dealt with that problem once too. Moved the copier to a dedicated circuit and solved the problem. The newer copiers seem to draw a lot more than the older ones.

#6913 - 01/14/02 01:55 PM Re: Power Spike on A Phase
WARREN1 Offline

Registered: 05/09/01
Posts: 184
Loc: Greenville, SC, USA
Have you tried a recording ampmeter over a longer period of time? Maybe one of those Flukes that record the harmonics? Harmonics would be my first impression since you have computers, printers and copy machines.
Just a thought.

#6914 - 01/14/02 02:16 PM Re: Power Spike on A Phase
Redsy Offline

Registered: 03/28/01
Posts: 2138
Loc: Bucks County PA
Copier gets my vote.

#6915 - 01/14/02 03:09 PM Re: Power Spike on A Phase
electure Offline


Registered: 12/24/00
Posts: 4226
Loc: Fullerton, CA USA

#6916 - 01/15/02 08:25 PM Re: Power Spike on A Phase

Registered: 12/24/01
Posts: 29
Loc: Omak, WA, USA
Copier,absolutly. Recently I responded to a call of a CB tripping every now and then with a chronic problem of lamps flickering. Turned out to be three copiers, any of which would cause the lamps to brown out and on the rare occasion when all three cycled at the same time the CB would trip.


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