# Electrical Question: How Water Dispenser **URL:** \ **Category:** Factual Questions\ **Created:** [September 17, 2011, 10:10pm UTC](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666 "2011-09-17T22:10:29Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [September 19, 2011, 3:24am UTC](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666/21 "2011-09-19T03:24:02Z")
> [@Digital\_is\_the\_new\_Analog](#): > > I suspect the concern is that a too-big circuit won’t trip when the elements attached to it misbehave. You could have something short out, heat up, and catch fire, and a too-big circuit will happily keep providing fuel. A proper circuit allows for what’s on it (in both run and startup mode) and not too much more, so it can catch a failure. > -D/a That’s basically it. While it’s a long shot, it could conceivable happen, along with wires, plugs and devices (outlets) overheating. Under-protected will result in nuisance tripping and overheating of the breaker, which will likely lead to failure of the breaker altogether once the spring is weakened enough. ---
**Author:** ![BrightNShiny](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@BrightNShiny](https://boards.straightdope.com/u/BrightNShiny)\ **Post date:** [September 19, 2011, 3:57am UTC](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666/22 "2011-09-19T03:57:56Z")
Thanks for the responses. I didn’t even consider the split outlet thing. The disposal has a switch over the counter to turn it on and off, so I guess that means it’s a split outlet? I don’t know how the circuits are wired. The breaker box was never labelled for some reason. When I get a moment, though, I’ll look up all the power requirements for the appliances and see what they add up to. I guess I’ll then have to test the breakers to see who is hooked up to what. ---
**Author:** ![boytyperanma](https://avatars.discourse-cdn.com/v4/letter/b/4491bb/32.png) [@boytyperanma](https://boards.straightdope.com/u/boytyperanma)\ **Post date:** [September 19, 2011, 4:03am UTC](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666/23 "2011-09-19T04:03:41Z")
> [@Digital\_is\_the\_new\_Analog](#): > > I suspect the concern is that a too-big circuit won’t trip when the elements attached to it misbehave. You could have something short out, heat up, and catch fire, and a too-big circuit will happily keep providing fuel. A proper circuit allows for what’s on it (in both run and startup mode) and not too much more, so it can catch a failure. > -D/a If you’re in the US and wiring to protect the end product you are doing it wrong. NEC wiring and breakers are to protect the wiring itself. If a device has specific voltage or amperage requirements that can’t be exceeded that protection needs to be incorporated into the device. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [September 19, 2011, 3:29pm UTC](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666/24 "2011-09-19T15:29:25Z")
> [@BrightNShiny](#): > > Thanks for the responses. I didn’t even consider the split outlet thing. The disposal has a switch over the counter to turn it on and off, so I guess that means it’s a split outlet? If there is a switch and the device is plugged into half of a duplex outlet, then yes. One can either buy a split outlet, or cut the strap on a regular duplex to create a split outlet. I would guess the latter. ---
**Author:** ![thelabdude](https://avatars.discourse-cdn.com/v4/letter/t/dc4da7/32.png) [@thelabdude](https://boards.straightdope.com/u/thelabdude)\ **Post date:** [September 19, 2011, 4:45pm UTC](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666/25 "2011-09-19T16:45:39Z")
Yes, in general breakers are sized to the wire, but the service needs to relate to the loads. It may make sense as hair driers get bigger and bigger to wire bathrooms with 20 amp service. A gargage disposal should rely on its own built in over load when jammed. Still for something maybe drawing 6.5 amps, I fail to see the wisdom of a dedicated 20 amp circuit. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [September 19, 2011, 5:50pm UTC](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666/26 "2011-09-19T17:50:52Z")
> [@thelabdude](#): > > Yes, in general breakers are sized to the wire, but the service needs to relate to the loads. It may make sense as hair driers get bigger and bigger to wire bathrooms with 20 amp service. A gargage disposal should rely on its own built in over load when jammed. Still for something maybe drawing 6.5 amps, I fail to see the wisdom of a dedicated 20 amp circuit. I agree. For the smaller ones, 6.5 amps may be appropriate; but a 1.0 HP Insinkerator like [this one](http://www.insinkerator.com/product/product.php?id=206&template=hhd) draws 10.2 amps, _average_. While it doesn’t warrant a 20 amp circuit, it will need all of 15 amp protection. I would hesitate to install a 20 amp circuit just in case somebody decided to put in a commercial grade disposal. On spec is a different story, of course. ---
**Author:** ![Khendrask](https://avatars.discourse-cdn.com/v4/letter/k/3e96dc/32.png) [@Khendrask](https://boards.straightdope.com/u/Khendrask)\ **Post date:** [September 20, 2011, 1:32pm UTC](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666/27 "2011-09-20T13:32:30Z")
> [@](#): > > At least two 20-ampere branch circuits are required to feed receptacle outlets for small appliance loads, including refrigeration equipment in the kitchen, pantry, breakfast room, and dining room. These circuits, whether two or more are used, shall NOT supply anything other than receptacles in these areas. Lighting outlets and built-in appliances such as garbage disposals, hood fans, dishwashers, and trash compactors are NOT permitted on these circuits. That is from the current US NEC for residential rough-in wiring, so the NEC says 20A. Also required currently is a minimum of one GFCI protected outlet every 24" of counterspace. Every bathroom is required to have at least one GFCI protected 20A outlet. ---
**Author:** ![thelabdude](https://avatars.discourse-cdn.com/v4/letter/t/dc4da7/32.png) [@thelabdude](https://boards.straightdope.com/u/thelabdude)\ **Post date:** [September 20, 2011, 2:31pm UTC](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666/28 "2011-09-20T14:31:42Z")
Note, homeowners pay for all that, not those writing the code. Do they have numbers showing refrigerators need 20 amp circuits? ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [September 20, 2011, 2:44pm UTC](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666/29 "2011-09-20T14:44:27Z")
refrigerator manuals have specified separate circuits for a long time. you can get a voltage sag and overloads on shared circuits especially at startup. ---
**Author:** ![boytyperanma](https://avatars.discourse-cdn.com/v4/letter/b/4491bb/32.png) [@boytyperanma](https://boards.straightdope.com/u/boytyperanma)\ **Post date:** [September 20, 2011, 7:15pm UTC](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666/30 "2011-09-20T19:15:00Z")
> [@Khendrask](#): > > That is from the current US NEC for residential rough-in wiring, so the NEC says 20A. No it doesn’t. Did you read your own cite? That says you need 2 20 amp circuits dedicated for convenience outlets. It doesn’t mention any specific requirements for the garbage disposal. [Previous page](https://boards.straightdope.com/t/electrical-question-how-water-dispenser/596666.md?page=1)