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 ghost307
Today at 04:10 PM
International Wire Colour Codes
by Tjia1981
Today 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 12
HotLine1 7
ghost307 6
renosteinke 6
Potseal 4
Who's Online
1 registered (HotLine1), 162 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#68418 - 08/08/06 07:26 AM Breaker: 250V or 125V?
Christopher.Banbury Offline
Junior Member

Registered: 08/07/06
Posts: 6
Loc: Brooksville, FL, USA
I purchased a refurbished battery backup that uses 125V/30A single phase power from a L5-30R receptacle. The on-board breaker is replaceable on the rear and is listed at 250V/30A. The reported trip amperage is 37.5A. Will this breaker throw at 4687W (125V) or not until 9375W (250V)?
Christopher Banbury, PE
Ark Engineering, Inc.
PO Box 10129, Brooksville, FL 34603
22 N. Broad ST, Brooksville, FL 34601
Phone: (352) 754-2424
FAX: (352) 754-2412

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....

#68419 - 08/08/06 10:08 AM Re: Breaker: 250V or 125V?
resqcapt19 Offline

Registered: 11/10/00
Posts: 2209
Loc: IL
The breaker doesn't care about the load watts. In its themal mode (overload) it only cares about the watts caused by the current flowing through its thermal element. These watts are based on the impedance of the thermal element and the current (amps).


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