circuit breaker as an input device

[Ivan Vegvary]

I have a sub-panel in my greenhouse that is fed by an incoming wire from th e main house panel. The incoming wire is directly feeding a 30 amp breaker , therefore I can disconnect the power to the panel by simply tripping the breaker therein. (Also within the panel are two additional 15 amp breakers , one for lights and the other for a single outlet.

I've always liked the convenience of the "breaker input" instead of hard wi ring the input directly to the panel. Does this method meet code? Any haz ards? Any down-side?

Thanks for all replies.

Ivan Vegvary

[Tom Horne]

the main house panel. The incoming wire is directly feeding a 30 amp break er, therefore I can disconnect the power to the panel by simply tripping th e breaker therein. (Also within the panel are two additional 15 amp breake rs, one for lights and the other for a single outlet.

wiring the input directly to the panel. Does this method meet code? Any h azards? Any down-side?

The code requires that all equipment be installed in accordance with it's l isting and marking. If you check that equipment in the listings you will f ind that you are instructed to use a tie down kit when using a plug on brea ker as a main breaker for the buss that it plugs on to. That is so that th e breaker can not be readily removed from the buss while it's buss clamps a re energized. Install the listed tie down kit and you are good to go.

Is the feeder to the greenhouse panel three wire or four? Is your greenhouse a detached structure in relation to the building in whic h the Service Equipment that supplies the feeder is located? If detached when was it built?

[RobertMacy]

Has anybody pointed out that breakers are designed to be ON most of the time, and once in a while kick OFF? and Switches are designed to be turned ON or OFF a lot? Simple thought process suggests that abusing a breaker to use it as a switch is going to have some long term, unexpected consequence. Like not turn ON when you want, or not kick OFF when you want.

[gfretwell]

Just be sure the breaker is marked SWD. Then it is listed for Switching Duty. Most small breakers are these days.

[Ralph Mowery]

You will see lots of things done, but that does not make it correct.

There are some breakers that are also designed to be used as switches an can be cycled off and on many times with out a problem.

[Art Todesco]

In my former church, the breakers were used to turn on and off the lights in the church, built in 1984. They were not, iirc, rated for switching duty. After a few years, many started getting hot to the touch. They were replaced with SWD. And, in time, they started failing the same way. There were 13 such switches each controlling 2 light fixtures. I always wanted to put relays downstream to control the lights. There were about 3 or 4 different lighting patterns used depending on the building use, but it wouldn't be difficult to have groups of relays doing the job. Never did it as I moved. In another commercial building I specified SWD breakers to control TV studio lights and the powers to be, put in a breaker box and a separate switch box because, as they told me, breakers used as switches make for bad breakers. This was in about 2001.

[woodchucker]

That does meet code and is the proper way of doing a small sub panel.

[woodchucker]

Get real, in most commercial establishments, the breakers are the switches.

[dpb]

NB that that applies only to fluorescent or high-intensity lighting circuits. I'd have to look up precisely the Code definition of "lighting circuit" to have 100% confidence but I'm pretty sure it doesn't include a general circuit that has one or two fluorescent fixtures included but is fluorescent-only or almost only load on same.

[dpb]

The breaker panel is/has been the switching panel in the church here "since forever". It was replaced from the 1920's original in the early-mid 60s and hasn't yet had a failure since. Some circuits are all fluorescent, most aren't but nothing bad has happened in 50 yrs or so.

I've never tried to discover what the rating is; I'd suspect there being some other issue w/ the gear in your aforementioned location.

[Ed Pawlowski]

The "main" he is using is not normally used as a switch but it gives him the ability to kill the panel if needed. The one breaker he is using as a light switch should be rated SWD. It is done every day in thousands of commercial and industrial buildings.

Your simple thought process needs to go a complex step further to understand this, I guess.

[VinnyB]

On Sat, 24 Aug 2013 06:47:29 -0700 (PDT), Ivan Vegvary wrote in Re circuit breaker as an input device:

Yes

No

[krw]

Yes, no, no.

This is perfectly normal (I do it all the time). Electricity doesn't care about the direction it "flows" through the breaker.

[krw]

There are breakers that are rated for "switch" use. Residential breakers are not.

[clare]

It is REQUIRED by code in most places - disconnect within reach of the door.

[Stormin Mormon]

There's no reason why you can't use an extension cord instead. It must be heavy duty of course.

Christopher A. Young Learn about Jesus

Ivan Vegvary wrote:

[bud--]

Also is required by the NEC - 408.36-D.

Good to see you at least once in a while.

[bud--]

From the UL "White" book: "Circuit breakers marked 'SWD' and rated 347 V or less are suitable for switching fluorescent lighting loads on a regular basis at their rated voltage.

Circuit breakers marked 'HID' have been investigated for switching high-intensity discharge lighting loads on a regular basis at their rated voltage."

I don't believe using "SWD" breakers on ordinary loads that are switched is required, but it is a real good idea, particularly when they are readily available. The only breaker I looked at recently (SquareD 20A) was marked both SWD and HID.

SWD and HID ratings are probably for the increased arcing from an inductive load. It would be interesting if they are tested for more on-off operations than an 'ordinary' breaker.

[jamesgang]

the main house panel. The incoming wire is directly feeding a 30 amp brea ker, therefore I can disconnect the power to the panel by simply tripping t he breaker therein. (Also within the panel are two additional 15 amp break ers, one for lights and the other for a single outlet.

wiring the input directly to the panel. Does this method meet code? Any hazards? Any down-side?

To be completely precise it's not flowing either direction. It's vibrating back a forth a tiny bit.

[krw]

The energy is "flowing" one direction (there is a source and a sink) but the breaker can't tell which end is which.