!2 gauge wire question

[MX1]

Is 12g wire good to go for the 120v applications in my control panel?

Power to the pump plugs, power to the PID, and to the 110v lights and switches?
It will be protected by a 16a 1 pole DIN Rail Breaker.

Thanks, I need to buy more wire to finish up, all I have is 16g left and didn't think that it was big enough.

Tim

 

[BigFloppy]

16g should handle enough power for 110v LED indicators

 

[augiedoggy]

I think I used 20 gauge. protected by a 1/2a fuse for much of mine... Like the stuff you find controlling the power switch and leds in a dc application in a computer.

16 gauge is good for 9 amps!

 

[Jerz]

Is 12g wire good to go for the 120v applications in my control panel?

Power to the pump plugs, power to the PID, and to the 110v lights and switches?
It will be protected by a 16a 1 pole DIN Rail Breaker.

Thanks, I need to buy more wire to finish up, all I have is 16g left and didn't think that it was big enough.

Tim

Typical #12 THHN/THWN is good for 600V; it's the amps you need to be concerned with... Overcurrent protection for #14 should be 15amps; #12 20amps; #10 30amps.

 

[augiedoggy]

we are talking about the switches that will be controlling contactors right? Whats the amp draw on these? I use a 24v dc powersupply for mine so that may be the biggest difference... otherwise all indicator lights buzzers and pids are using less than an amp (I do believe a 1/2 amp actually)

 

[MX1]

The contractors are run with 10g wire.

I am really talking about the wire from the terminal block that is feed from my 16a breaker, to the 110v pump outlets and the 110v power in to the PIDs and such. I am having a hard time thinking that 16g wire is good enough for that.

Maybe I am just scared...lol.....

 

[bajaedition]

you need to state the amp draw of the things you want to run.
your wire feeding the pumps need to be rated at the total draw of the pumps x 1.25 or more.

 

[grandequeso]

Look at the rating of the cord that came from the factory attached to the pump. Doubt it's larger than 16g

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[bajaedition]

The contractors are run with 10g wire.

I am really talking about the wire from the terminal block that is feed from my 16a breaker, to the 110v pump outlets and the 110v power in to the PIDs and such. I am having a hard time thinking that 16g wire is good enough for that.

Maybe I am just scared...lol.....

if you are running the wire off a 16 amp breaker, the wire should be rated for 16 amps or better, otherwise you are using the wire as a fuse.
wire that feeds the plugs and stuff needs to be rated from the breaker.

 

[MX1]

Thx for all the input guys


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[MX1]

The pump should be the highest draw on the 120v side, and it draws less that 2 amps iirc.
I will run the 12g for the hot runs.

Again thanks for all the help

T


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[augiedoggy]

if you are running the wire off a 16 amp breaker, the wire should be rated for 16 amps or better, otherwise you are using the wire as a fuse.
wire that feeds the plugs and stuff needs to be rated from the breaker.

I dont quite understand this logic.... I plug things into my wall outlet that have 2 amp draw with 16gauge cords... my breakers are 15 amp on those outlets... the OP will never get a load anywhere close to 16 amps with switch and lights and even pumps wired on the line...
16 gauge is fine but realistically even it is rated at about 2-4x the amp capability (9amp) than whats usually needed...
in my setup I use 12v pumps so I could have used 22gauge if I wanted to and still met codes and been safe if I beefed up the wire powering my 12v/24v powersupply to terminals, which I did.
If I were using two 120v ac pumps I would likely power those outlets with 14 or 16 gauge even though its really overkill...


I know the hot element line in the contractor relays need to be 12 or 10gauge but the coil wires going to the switch likely only require less than half an amp...

 

[kenh]

I dont quite understand this logic.... I plug things into my wall outlet that have 2 amp draw with 16gauge cords... my breakers are 15 amp on those outlets... the OP will never get a load anywhere close to 16 amps with switch and lights and even pumps wired on the line...
16 gauge is fine but realistically even it is rated at about 2-4x the amp capability (9amp) than whats usually needed...
in my setup I use 12v pumps so I could have used 22gauge if I wanted to and still met codes and been safe if I beefed up the wire powering my 12v/24v powersupply to terminals, which I did.
If I were using two 120v ac pumps I would likely power those outlets with 14 or 16 gauge even though its really overkill...


I know the hot element line in the contractor relays need to be 12 or 10gauge but the coil wires going to the switch likely only require less than half an amp...

The wires running to my PIDs are 22 gauge and they aren't protected by a 5 Amp breaker.

Also, every light, radio, etc plugged into an outlet in my house has a power cord rated at less than 15 Amps and they are all plugged into 15 Amp outlets.

 

[augiedoggy]

The wires running to my PIDs are 22 gauge and they aren't protected by a 5 Amp breaker.

Also, every light, radio, etc plugged into an outlet in my house has a power cord rated at less than 15 Amps and they are all plugged into 15 Amp outlets.

Thank you, exactly my point.

If your going to put more than one device on the same breaker load than the breakers has to be rated for at least for the maximum of all the devices that are running off it at once at the same time... if you run more that 15amps worth of appliances then the breaker trips..
By the logic stated earlier someone would have to put each switch and light on its own breaker...

 

[Jerz]

The wires running to my PIDs are 22 gauge and they aren't protected by a 5 Amp breaker.

Also, every light, radio, etc plugged into an outlet in my house has a power cord rated at less than 15 Amps and they are all plugged into 15 Amp outlets.

The wires to your pid's should be protected by an appropriate sized fuse within your panel. I used #14 gauge to my pids and have my hot bus protected by a fuse that is not more than 15amps. My two 5500watt heater elements have 10 wire in the control panel between the contactors and the heater elemets and that wire is protected by fuses sized not more than 30amps. My panel is fed with a 50A 120/240V gfi breaker, the cord is #6/4 SO... As long as you fuse the wire appropriately to the wire size than you can use whatever size wire you want... If you undersized the wire and the fuse blows well then you should upgrade the size of your wire... definitely not rocket science; your simply protecting the wire according to code.

 

[augiedoggy]

It was recommended to me to use a 1/2amp fuse for pid power and thats what I've done..and since theres so little ampherage required anything under 18 gauge is really overwired, not that it will hurt.
I've never had that fuse blow... a I would think 15 amp fuse wouldnt do as much good at all

 

[Jerz]

It was recommended to me to use a 1/2amp fuse for pid power and thats what I've done..and since theres so little ampherage required anything under 18 gauge is really overwired, not that it will hurt.
I've never had that fuse blow... a I would think 15 amp fuse wouldnt do as much good at all

It really doesn't matter.... I run more than the three pid's on the #14... pids, lights, pumps and meters so I have one fuse to handle that load. I *could* downsize the wires to the pids from the hot bus but then I should fuse that wire change so the wire is protected from overcurrent.

 

[bajaedition]

I dont quite understand this logic.... I plug things into my wall outlet that have 2 amp draw with 16gauge cords... my breakers are 15 amp on those outlets... the OP will never get a load anywhere close to 16 amps with switch and lights and even pumps wired on the line...
16 gauge is fine but realistically even it is rated at about 2-4x the amp capability (9amp) than whats usually needed...
in my setup I use 12v pumps so I could have used 22gauge if I wanted to and still met codes and been safe if I beefed up the wire powering my 12v/24v powersupply to terminals, which I did.
If I were using two 120v ac pumps I would likely power those outlets with 14 or 16 gauge even though its really overkill...


I know the hot element line in the contractor relays need to be 12 or 10gauge but the coil wires going to the switch likely only require less than half an amp...

ok, get this

we use a 16 amp breaker and then we use 12 gauge wire to complete the circuit. We are protecting the entire circuit the 12 gauge wire is going to, ther can be things on this circuit not drawing 12 amps that is true, but the circuit will be protected by 16 amps and 12 gauge wire is proper for that.
when you plug in a appliance to one of the plugs on the circuit you are actually plugging in an appliance to the circuit, that can have a chord rated at whatever the appliance needs.

in other words, the breaker is protecting the circuit, not that appliance
if the appliance were to be hard wired into the circuit, then that is another matter.

A union electrician takes 5 years of classes to learn the code and when one section starts and another ends, Engineers take 4 to 5 years full time of classes. They learn where and when each code applies, the wire feeding the appliance, and the wire feeding the device the appliance plugs into come from 2 different places in the code. Unless the appliance is hard wired where it cannot be disconnected.

that is why a lamp can have such a small wire in it's chord but you plug it into a receptacle that is fed with 14 gauge wire.

 

[augiedoggy]

ok, get this

we use a 16 amp breaker and then we use 12 gauge wire to complete the circuit. We are protecting the entire circuit the 12 gauge wire is going to, ther can be things on this circuit not drawing 12 amps that is true, but the circuit will be protected by 16 amps and 12 gauge wire is proper for that.
when you plug in a appliance to one of the plugs on the circuit you are actually plugging in an appliance to the circuit, that can have a chord rated at whatever the appliance needs.

in other words, the breaker is protecting the circuit, not that appliance
if the appliance were to be hard wired into the circuit, then that is another matter.

A union electrician takes 5 years of classes to learn the code and when one section starts and another ends, Engineers take 4 to 5 years full time of classes. They learn where and when each code applies, the wire feeding the appliance, and the wire feeding the device the appliance plugs into come from 2 different places in the code. Unless the appliance is hard wired where it cannot be disconnected.

that is why a lamp can have such a small wire in it's chord but you plug it into a receptacle that is fed with 14 gauge wire.

That makes sense..and that wasnt at all what I dont understand. I was looking at it more as since this is dedicated device and its internal wirings load isnt subject to change outside of whats permanently wired to it or designed to be plugged into it and the current draw is going to be so small (2-3 amps with pumps running?) Then why not put some kind of circuit protection in thats close to the normal draw since it would be more likely to trip or pop if there was an actual problem and more likely to do so quicker and protect devices on that circuit? Isnt this why devices use fuses rated at close thier power consumption?
So why the 16 amp breaker? and why over wire everthing so much when it makes just increases cost, takes up more room and provides less protection to the devices on the circuit? Thats my real question. There is something I'm likely missing and I really want to know why.. The lamp you mentioned doesn't have 12 gauge wire going to the switch and 60w rated max bulb because it would be inconvenient expensive pointless overkill so why do it here?

I do not have an engineering degree Nor am I a licensed electrician so I'm asking those who are so I understand this better.
Which is why I stated I dont quite get it... I asked because I wanted to understand the reason or reasoning not because I wanted to be talked down to.

 

[Jerz]

I dont quite understand this logic.... I plug things into my wall outlet that have 2 amp draw with 16gauge cords... my breakers are 15 amp on those outlets... the OP will never get a load anywhere close to 16 amps with switch and lights and even pumps wired on the line...
16 gauge is fine but realistically even it is rated at about 2-4x the amp capability (9amp) than whats usually needed...
in my setup I use 12v pumps so I could have used 22gauge if I wanted to and still met codes and been safe if I beefed up the wire powering my 12v/24v powersupply to terminals, which I did.
If I were using two 120v ac pumps I would likely power those outlets with 14 or 16 gauge even though its really overkill...


I know the hot element line in the contractor relays need to be 12 or 10gauge but the coil wires going to the switch likely only require less than half an amp...

Well... without getting into a lot of BS... all of your household appliances should be UL listed for their purpose; meaning they are approved to plug into the receptacle. Technically if you cut the end off of your motor cord that voids the UL listing. Underwriters Labs deems these appliances safe to plug in and I know most everything in my house (stereo, tv, washing machine, etc) is internally fused.

 

[augiedoggy]

Well... without getting into a lot of BS... all of your household appliances should be UL listed for their purpose; meaning they are approved to plug into the receptacle. Technically if you cut the end off of your motor cord that voids the UL listing. Underwriters Labs deems these appliances safe to plug in and I know most everything in my house (stereo, tv, washing machine, etc) is internally fused.

Yes but wouldnt the internal breaker in the panel be acting as a fuse? and those devices have a fuse or multiple fuses rated just over the max load they would be expected to see right?

 

[Jerz]

Yes but wouldnt the internal breaker in the panel be acting as a fuse?

Sure... Breakers and fuses basically are the same thing when talking about overcurrent protection.

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[augiedoggy]

Sure... Breakers and fuses basically are the same thing when talking about overcurrent protection.

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So wouldnt building an internal circuit 4 amp circuit with 12 gauge and a 16 amp breaker be like building say a 6 amp powersupply for a tv with a breadboard capable of supporting 20a of current and then putting a 20a fuse on it so if theres component failiure the fuse wont blow until major catastrophic failure or damage is done and something else has a meltdown to open the circuit??

I just think it makes more sense to actually make the breakers the weaker link in the chain than other things that go poof and smoke and then can start on fire if they are still receiving juice... I realize to do it right one would ideally want every device on its own breaker of fuse but a 5mp breaker and 18 gauge wire would still be more effective protection than a 16 amp breaker and 12gauge right? Or No?

 

[kenh]

The wires to your pid's should be protected by an appropriate sized fuse within your panel. I used #14 gauge to my pids and have my hot bus protected by a fuse that is not more than 15amps. My two 5500watt heater elements have 10 wire in the control panel between the contactors and the heater elemets and that wire is protected by fuses sized not more than 30amps. My panel is fed with a 50A 120/240V gfi breaker, the cord is #6/4 SO... As long as you fuse the wire appropriately to the wire size than you can use whatever size wire you want... If you undersized the wire and the fuse blows well then you should upgrade the size of your wire... definitely not rocket science; your simply protecting the wire according to code.

Why?

The timer that runs my dryer is not protected by its own fuse. The controller that runs my home heating system is not protected by its own fuse, none of the plug-in lamps in my house have fuses. And come to think of it, none of my ceiling lights have their own fuses!

But my coffee pot and toaster oven and TV do have their own fuses, for main incoming power only. You could break any of these down to their parts too. I'm sure my TV has sub-components that draw less than the whole. I know my coffee pot does because it has a digital clock & timer.

 

[MX1]

For good or bad, I am not using fuses. The diagram I am using does not call for them.


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[augiedoggy]

Why?

The timer that runs my dryer is not protected by its own fuse. The controller that runs my home heating system is not protected by its own fuse, none of the plug-in lamps in my house have fuses. And come to think of it, none of my ceiling lights have their own fuses!

But my coffee pot and toaster oven and TV do have their own fuses, for main incoming power only. You could break any of these down to their parts too. I'm sure my TV has sub-components that draw less than the whole. I know my coffee pot does because it has a digital clock & timer.

alot of this stuff does have built in protection like pico fuses and such designed to blow and protect the rest of the circuit but I see the point your making... the timer in your dryer is also likely run with 18 or 20 gauge wire and not 12 gauge with an internal 16 amp fuse or breaker. still because its a separate circuit being split off of a lager 30a protected line the 16a breaker protecting the 120v source is better than nothing.
I guess we are splitting hairs here.

 

[augiedoggy]

For good or bad, I am not using fuses. The diagram I am using does not call for them.


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nor does a pid call for 20a rated wire to power its less than 1/2amp power requirements

 

[MX1]

Well played good sir! Lol


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