Search
sitemap button
Search using google with ads

 Tweet button  

Are both sides of double breaker 30 amp or each of them 15 amp ?

Tech support options
Resource: safe electric wiring
2023
Use only 600 volt wire.
Lamp cord, extension cords are not rated 600 volt.
Use copper wire only. Aluminum wire is fire risk and should be avoided or installed by professional.

30 amp breaker use 10 gauge /
120-240 volt 30 amp outlet can be installed on 30 amp breaker only/ use 10 gauge wire ... cannot be connected to 15-20-40 amp breaker.

Orange/ #10 gauge wire, with ground ... 30 amp capacity. Safe maximum: 30 x 80% = 24 amps.
Buy:
10-2 gauge/ 30 amp
10-3/ 30 amp
Southwire electric tools
Yellow 12 gauge 20 amp
120 volt 20 amp outlet can be installed on 20 amp breaker, but not 15 amp breaker/ use 12 ga wire.
... cannot be connected to 30-40 amp breaker. 1

Yellow/ #12 gauge wire, with ground ... 20 amp capacity. Safe maximum 16 amps.
Buy:
12-2 gauge/ 20 amp
12-3/ 20 amp

NMB is house wiring
UF is underground
Rolls of stranded wire
HOOK UP Wires
Southwire armored cable cutter
Electrical tools must be insulated.
Always best to disconnect power, but insulation failure, lack of proper grounding, grounded neutral, lack of GFCI, out-of-code wiring, generator operating without transfer switch, and other problems still pose a risk to anyone working on electric power ... even when breaker is off.

Buy:
Electrician tools kits
KLEIN TOOLS
Tools kits
IRWIN tools
KNIPEX

Telephone cable knife
Low Voltage Mounting Bracket for Telephone
multimeter
Multimeters
Voltage is tested across two separate wires. Ohms or resistance is tested across both ends of same wire. Amperage is tested along one or two points on same wire.
Buy:
Analog multimeter
Multimeters at Amazon
Klein multimeter
Electric testers at Amazon
Clampmeter for testing amp flow on line

240 Volt circuit breakerQuestion: Are both sides of double breaker 30 amp or 15 amp ?
Answer: Both are 30 amp


You can use a double breaker as two single breakers to supply 120 volt to two separate circuits..
If you have a 30 amp double breaker, you can connect a single 10 gauge hot wire and it will work for 120 volt. You would NOT connect a 12 or 14 gauge wire to the 30 amp breaker or it creates a fire hazard.

You can create a 240 breaker by combining 2 single-pole breakers, they must be located side-by-side, and code requires a 'common bar' between the breaker switches so if one trips, then the other breaker also trips.
You would NOT use two 15 amp breakers. You would use two 30 amp breakers and 10 gauge wire.

Calculations
Volts x Amps = Watts is a basic electrical formula
Volts (V or E) x amps (A or I) = watts (P or power)

-Let's calculate watts for 120 volt single breaker
 -15 amp single breaker. 120 volts x 15 amps = 1800 watts of power
 -30 amp single breaker. 120 volts x 30 amps = 3600 watts of power.

-Calculate watts for 240 volt double breaker.
-15 amp double breaker. 240 volts x 15 amps = 3600 watts of power
 -30 amp double breaker. 240 volts  x 30 amps = 7200 watts of power.

With 240 volt, the watts or power is doubled  .... Amps are not cut in half

Since each leg of 240 volt circuit offers 120 volt potential to ground, then you're getting two legs of out-of-phase 120 volt when you use double breaker, and doing so doubles the voltage and doubles the watts (power), it does not halve the amps.

This shows that each leg of 30 amp double breaker delivers 30 amps, and not 15 amps. .

Mr Laing emailed a question.
He asked,
Since each side of 30 amp double breaker is 30 amps, is the total 60 amps?


The answer is no.
Maximumm 30 amps can flow on each side or each leg of a double breaker, but it is the same 30 amps flowing IN on one leg and back OUT on the other leg. .. and it's never 60 amps.

To begin, each circuit requires 2 wires to complete the circuit. The 30 amp double breaker has 2 wires, and each wire is called a leg.

Amperage is the current of electrons that are moving back n forth between each leg.... so if the load is drawing 30 amps, then 30 amps worth of electrons are flowing IN on the first leg and back OUT on the second leg .... and this movement of electrons through the load is what powers the load.

Because of how the generator produces AC electricity, the current of electrons is constantly changing direction.
60 times per second, the electrons slow down and come to a brief halt, and ....
then start moving the reverse direction.
And when the electrons reverse, they move IN on second leg and back OUT on the first leg ... and it's all the same electrons flowing through both legs of the breaker, going back-and-forth, one direction then the other.
Because it's the same electrons, the amps or electrons never exceed 30 amp ...
because the breaker maximum lets 30 amps worth of electrons flow, and if more electrons are present, the breaker trips.
At no point are 60 amps allowed to flow through a 30 amp breaker.
Read  how a generator works
240 volt breakers

If a 30 amp double pole breaker was 15 amps on each leg, then a 20 amp double breaker would be 10 amps on each leg. And a 15 amp double breaker would be 7.5 amps on each leg. There is no 10 amp circuit breaker or 7.5 amp breaker made for residential breaker box.
There are 5-10 amp fuses etc made  for various applications, such as a line fuse for automotive or 12 volt DC breaker for boats.

Residential transformer converts high voltage distribution power into lower voltage residential power.
Electricity from the grid is alternating current.
Electrons on the wire move one direction, then come to a stop, before moving the other direction. This is caused by the rotation of the power plant generator, where N and S poles of a magnet pass over coils of wire.
In a process called magnetic induction, the electrons move one direction on the wire when the N pole of magnet passes the coil, then momentarily come to a stop and reverse direction when the S pole of magnet passes the coil of wire.

In a simplified version of events, one end of the generator coil is connected to one wire, and the other end of generator coil is connected to the other wire.
ResourceRead more detail

Each residence receives power from a transformer.
The purpose of the transformer is to convert high voltage from the generator into lower, usable voltage for household use.

Two high voltage wires from the generator connect to the Primary side, while the secondary or residential side delivers 3 lower voltage wires to the residence.

So a transformer has 2 sides, the primary and secondary with a shared iron core. The primary side has 30 times more wraps of wire around the iron core than the secondary, yeilding a ratio of 30 to 1.
The ratio is how voltages are lowered. The ratio determines the voltage delivered to the secondary or residential side.

Fig-T1 show two high voltage wires connected to the Primary side of a residential transformer.
The high voltage wires energize the Primary coil with electrons that are oscillating back and forth, 60 times per second, in an endless cycle that matches the rotation of the generator.

The back and forth motion of electrons on Primary side creates a magnetic field on the iron core.

Due to the shared iron core, the Secondary side of the iron core is also magnetized, which causes electrons on the Secondary coil to start oscillating back and forth at 60 times per second, same as primary side and same as rotation of the generator.
What this means, is electrons on the Secondary or residential side are oscillating with AC electricity in the same frequency (cycles or Hertz or Hz) as the primary side, except at lower voltage and higher amperage.
Why lower voltage on secondary or residential side? The 30:1 turns ratio causes lower voltage.
Why are there higher amps on secondary or residential side? Volts and amps are inversely proportional. So when volts are lowered by the 30:1 ratio, then amps are raised by the same ratio.

This  indicates that high voltage distribution wires only deliver a few amps to each transformer (8 amp maximum per 250 amp residential service), allowing many homes to draw electricity from a single power line. Resource: Amp rating of power lines.

It works nicely because 120-240 voltage (the force that pushes electrons, also called Volts, or abbreviated as V or E) can be safely controlled by small switches, relays, cell phone chargers etc contained within steel and plastic enclosures, while the amperage (the flow of electrons, also called amps or current, or abbreviated as A or I) is controlled by circuit breakers and then distributed to Loads (lights, appliances, motor etc) using correctly sized wire to match amp rating of breaker.

In residential service, each Hot wire (X1 and X2 in Fig-T1) tests 120 volt to Neutral and also 120 volt to Ground.
So each Hot wire carries 120 volt potential, but when testing across both Hot wires, the test shows 240 volts because each leg (X1 X2) is 'out of phase' with the other.

Out of phase means the electrons on each wire are oscillating back and forth, going different direction from electrons on other wire.
Since both hot wires in a 240 volt circuit come from opposite ends of the Secondary coil, then each hot wire is 'out of phase' from the other hot wire because electrons are always accelerating different directions on each wire.
This means that each leg of a 240 volt circuit is delivering the same amount of voltage.
When you use two hot legs for a circuit, it doubles voltage and doubles power, like pedaling a bicycle with two legs instead of one.
Contrast with 120 volt circuit that uses only 1 hot leg and a neutral, then the circuit delivers less power, like pedaling a bicycle with 1 leg.

Footnote 1: taking 2 Hots from same side of coil yields no voltage when connected to an appliance since both Hots are in phase with each other... each Hot must come from the opposite end of Secondary coil.
Footnote 2: Household voltage remains unchanged (except for brief surges etc) no matter how many Loads are being operated (this assumes correct size wire is used). While amps, or flow of electrons, rises and falls depending on number of Loads, with more electrons flowing when more Loads are ON.

Resources:
Figure volts amps watts
Formulas for ohm's law
What is electricity
How a generator works
Difference between single-phase and 3-phase
Electricity from power plant to end user

More detail
69,000-500,000 volt Transmission and Sub-transmission lines (from power plant to substations) and 4500-7200 volt distribution lines (from local substation to local end user) are high voltage, low amperage to reduce heat loss. Ampacity of power lines
Heat occurs when voltage pushes amperage (current of electrons) against the matrix, or atomic structure, of the conductor. The conductor always offers resistance to the movement of electrons. Resistance is like friction, causing heat that pushes back against the flow of amperage ... reducing efficiency, raising costs, and lowering grid reliability.

Transformers located at power plant change the high-amperage electricity produced by the generator into lower amp, high volt electricity.
High voltage and low amperage means more force is pushing fewer electrons against the conductor matrix, which means less resistance and less heat.
By reducing losses from heat, electricity can be transmitted longer distance without losing power. Read about power generation and transmission

To prevent electricity from jumping (arcing) to other wires, or to the transmission tower, or to the earth, high voltage conductors (wires) are suspended high above the ground and spaced far apart, utilizing air as an insulator. The higher the voltage, the more space is needed to keep the voltage under control.
Keeping high voltage under control requires large switchgear, making it expensive to control, and impractical for residential and commercial use.
Just imagine if every switch inside a home had to be inside a 10' high cabinet, and wires couldn't be located closer than 3 feet away from any building material.

To solve the problem, and keep the balance of cost and function, transformers are used throughout the grid to 'step up' and 'step down' voltages to meet various objectives.

Distribution transformers that deliver power to homes and businesses step down the 7200 volt distribution electricity to a level that does not require wide space between conductors etc. Using lower voltage for the end users also allows standardized manufacture and installation of small, safe, and reasonably-priced wires, breakers, switches, appliances etc.
Standard voltages.
Voltages are a function of power generation, mathematics of electricity, transformer configuration, availability of conductive materials, cost, safety, and need for standardization. Standardization makes it possible to mass produce electrical devices, switches, appliances etc.

Transmission, sub-transmission and distribution voltages range widely from 4500 volt to 500,000+ volts. The voltages are standard, for example a sub-transmission line might be 69,000 volts, but not 59,000 volt.
Why? Standard voltages are predictable so that installation practices can be uniform ... this means power companies can send crews anywhere in the state or to other states to restore power following natural disaster. It means that power companies can connect all generator stations together into a single grid that picks up shortages in one area by sending power from other generators. And if one or more generating stations goes offline, they can be restarted by pulling power from other stations. It also means transformers, conductors, insulators, poles, and switchgear can be mass produced and sold across the nation.

Voltages at homes and businesses are also standardized, ranging from 120 volt to the maximum 600 volt. Industrial voltages can be considerably higher, and often produced by on-site generator and substation.

By NEC code, all wire and cable used for permanent installation inside homes and businesses must be rated 600 volt (printed on wire insulation or embossed onto the sheathing of each cable).
Note: Extension cords are not rated 600 volt and cannot be used for permanent in-wall wiring and have limited applications. Read more about uses for extension cords

Why 600 volt? Because 600 volts is the maximum voltage that distribution transformers are designed to supply off the secondary side of end-user transformer.
Note that 600 volts is only supplied to commercial installations when that specific service is required.
Most businesses receive 120-208-240-277-480 volts depending on requirements.  
Homes never receive 600 volt service, and there are no household devices or appliances made for such voltage.
Homes receive standard 120-240 volt service, which can range from 115 to 250 volts since voltages are never precise, but expected to be within range to ensure appliances and devices operate reliability. The voltage might vary slightly over time, and except for brief surge events, is generally stable and unchanging.
Buy:
Kilowatt hour meter
Amperage and heat
The breaker responds to amperage, not voltage.
The breaker does not respond to ordinary household voltage spikes, for example when inductive loads like a motor activates, but a breaker can trip if direct lightning strike energizes the wire with enough voltage. For voltage spikes such as nearby lightning strike, motor start-ups etc, a surge protector is used. Resource: How to wire whole house surge

Household circuit breakers are designed with thermal and magnetic properties that respond to different overcurrent conditions. Overcurrent means too much current, and since current is the flow of electrons on the wire, then overcurrent means too many electrons getting pushed down the wire by the force of voltage.
The thermal (heat) mechanism located inside breaker expands in response to temperature and is calibrated to trip when current exceeds breaker rating. Thermal protection is designed to respond slowly (not instantly). This allows overcurrent to exceed breaker rating for a moment so when a motor start-up pulls a surge of amps, then the breaker does not trip.
The magnetic protection is for emergency conditions such as short circuit or faults where the magnitude of current surpasses normal amp flow on the line. The surge of electrons passes through a coil of wire located inside the breaker, which creates a strong magnetic field, causing the breaker to trip 'instantly.'
Thermal and magnetic protection means the household breaker is designed to trip 'instantly' when a short circuit occurs, but delays an appropriate amount of time before tripping in the event of ordinary overload (when a circuit is briefly drawing too many amps).

If there is a short circuit (insulation failure), where electrons (amps) start running wildly into the ground wire (assuming installation is correctly grounded), then wires and devices etc can melt before the breaker trips. Wires don't always melt because the breaker should trip instantly, but if the short is caused by a loose connection where there is arcing, then damage can occur. Why you need ground wire

Since the electric code requires wires and devices to be rated for 600 volt, how could a 600 volt wire melt when household voltage is much less?
a) The voltage did not increase during the short circuit. The voltage didn't spike over 600 volts. It's still 120-240 volt, because the grid transformer didn't suddenly change it's construction parameters and deliver more voltage.
b) The amp rating of the copper wire did not not change. Each wire has a amp rating. For example 10 gauge wire is rated 30 amps. NEC Code says: safe maximum ... 80% x 30 amps = 24 amps for 10 ga wire.
Wires are like lanes on a freeway, and amps are like the cars. Wires only allow so many cars before the lanes are full. Larger wires have more lanes.

c) So what changes when a short circuit happens? Answer: The flow of amps on wire increases because the short is allowing electrons to flow into earth, and voltage will push electrons down the wire in massive numbers until the wire melts or the breaker's magnetic coil causes breaker to trip.
d) But why does the wire get hot when more electrons are on the wire? Why does a wire melt?
e) The answer is, if a circuit is shorted to ground, then voltage keeps pushing more and more electrons against the matrix of a conductor (copper wire). Except the copper wire is a fixed size, and the copper matrix only allows so many electrons to flow before the resistance limits the flow of electrons. Electrons begin to pile up, like an impatient traffic jam. The more electrons on the wire, the higher the resistance. Resistance is like friction that causes heat. So the massive flow of electrons causes more heat on the wire.

f) Mathematics
First formula: Volts x Amps = P (Power or watts). Volts do not change, but more electrons (amps) are flowing down the wire, so amps are rising. This means P (power or watts) is rising. Power goes up during a short circuit.
Second formula: IČ (amps) x R (resistance) = P (Power or watts). The first formula tells us that Power is going up. If P is going up, then [amps x resistance] must be going up. But the wire limits how many amps (electrons) can flow on the wire. Once the number of electrons approaches the maximum, then the number of electrons is restricted. This means the resistance must go up../. which slows the electrons, like too many cars on the road. Too many electrons on the wire and the wire gets hot causing the breaker to trip. If there is an arc caused by loose connection, then the excess power can melt the wire almost instantly before the breaker trips. One of the functions of the ground wire is to absorb the flow of electrons, redirecting them into earth. This puts less stress on the wire and breaker and helps preserve the electrical installation.
If the wire does not have a circuit breaker or ground wire, or if wire is too small for the amp rating of breaker (each a strict violation of electrical code), then the wire will overheat, melt, arc, or cause fire ... depending on unpredictable nature of out-of-control electricity at that moment.

The math tells us that amps (the flow of electrons on the wire), held back by resistance, is the cause of heat. If there was no amperage flowing, there would be no heat.
Question:
Can I connect 120 volt 30 amp single-pole load to 30 amp double breaker?
Answer: Yes. 30 amp requires 10 gauge wire. Always use solid copper wire, and make connections very tight.

Question:
Can I connect 120 volt 15 amp circuit to 30 amp double breaker.
Answer: Generally no.
30 amp breakers are made for 30 amp loads only.

You can use smaller 14 gauge wire if and only if you install 15 amp line fuse, or surface mount breaker, or din rail mounted breaker on the 14 ga wire.
Multiple overcurrent protection (breaker, fuse) on a circuit is ok.
The fuse or breaker must be inside a box or subpanel with cover, and must be easily accessible and not concealed inside a wall.

The fuse can be installed at the load or anywhere on the line and still protect entire length of wire.
Resource: Fuseholders


The best solution is always connect to correct size breaker, or install tandem breaker if panel does not have enough spaces.
Not enough space in breaker box

Question:
My circuit breakers are 20 amp, but lights switches, outlet and the wall timer are rated for 15 amp? Is this safe?
Answer: Yes. It is code to install 15 amp switch, outlet, dimmer, timer etc on a 20 amp breaker.
However if breaker is 15 amp, then only 15 amp switches and outlets, gfci etc are permitted.
Ratings for each device are embossed into the device.

Of course if the outlet or switch supply power to 120 volt 1-Hp pool pump that draws 16 amp, then you want a 20 amp switch or outlet. Each device has a rating for volts and amps.
Add up total wattage being controlled by the switch etc, and divide by 120 volts to calculate amp draw of load.

Question:
Isn't electricity 110 volt and 220 volt? Your website says 120 and 240.

Answer: 120-240 is correct. Check the rating label on each appliance, TV, etc. and it often shows 115 or 125 volts. Electric water heaters show 240 volt. Electric device manufacturer's spec sheets show 120-240. Switches and outlet and timer manuals show 120-240.
Look at switch or outlet, and the 120-240 volt rating will be embossed somewhere on the device.

Switches rated for 120 can only be used on 120 volt circuits. Switches rated for 120-277V can be used for 120 and 240V, and used for commercial 208, 277 volt. Switches rated for 240V always have 4 screws, and are double-pole, and can be used for 120, 208, 240, but not 277 volt.
ResourcesWhat is 208 volt    What is 277 volt

Actual voltages at each location vary. Folks have emailed saying they test 250 volt, and their grid supplier says it's 'normal.' My home measures 236 volts most times. And 122 volt on the 120 volt lines.
Anything greater or less than 80% rated value can damage inductive loads like motors, while resistance loads like incandescent light bulbs just get brighter or dimmer.
Buy:
Kilowatt hour meter

Resources:
Fuseholders
Not enough space in breaker box
See inside main breaker box
Basic household wiring diagrams
Why ground wire is needed
How to wire switches
Question:
Isn't a 30 amp double pole breaker is same as two 30 amp single pole breakers stuck together, so I can put 30 amps on each leg?
Answer: Yes, because the breaker draws 30 amps from each leg ... 1 leg per each busbar.
You might be better using two individual 30 amp breakers since a double breaker has a connection bar and both sides will trip if either leg trips.


Question:
Can I use 10 gauge wire on a 20 amp breaker.
Answer: Yes as long as the large wire fits each device (outlet, switch etc) and the connections can fit inside your junction boxes.
It is possible that a larger wire will run cooler and save energy, especially if distances are greater than 50-100'.

Question:
If you load a panel up with only single pole breakers can you put 200 amps on each leg?
Answer: No.

A main breaker panel has 2 hot busbars (legs), with each busbar receiving power from a different end of the Secondary coil on the transformer.

A main breaker is a large-amperage double breaker, same as any double breaker in the breaker box, except it supplies power to each busbar. So your question is like asking if you can draw 60 amps off a 30 amp double breaker ... the answer is NO.
Why? Each leg on the 30 amp breaker delivers max 30 amp. One or the other leg on the 30 amp breaker will trip at 30 amp, and cause other leg to trip also. This means the 30 amp double breaker has max 30 amp rating.

Same with 200 amp main breaker ... 200 amps on each leg would be 400 total amps.
If you draw 400 Amps, the main breaker will trip ... because the 200 Amp main breaker has a limit of 200 amps. So a 120/240Volt panel with a 200 amp main breaker has maximum 200 Amp rating, no matter if loads are 120Volts or 240Volts.

Note, breakers are generally not fast-acting. They allow a certain amount of over-amps before the heat causes breaker to trip, which means actual amperage can exceed the breaker's amp rating. However, chronically overclocking breakers will cause the breaker and busbar to get warm or hot, then cool off when no power is being used, and then get warm or hot again as power is used again. Over time, this causes busbar to get soft and start arcing with the breaker ... and will eventually destroy that tab on the busbar, and ruining breaker. Breakers should not be warm or hot. Use hand to test if breakers are running hot when under load.
circuit breakers are warm
Overheated main breaker can cause permanent damage to the busbar ... destroying the breaker box.
If individual breaker is overheating and melts 1 busbar tab, then a new breaker can be moved to another slot, and panel is not destroyed.

Keep loads within the safe maximum for each breaker. The safe maximum calculation is 80%.
If breaker is rated 30 amp, then 30 x .8 = 24 amp safe maximum.
200 amp main breaker x .8 = 160 amp safe maximum.
Add up wattage of loads on each breaker, and divide by voltage to get amperage at full load. Add up total amperage on all breakers to determine if electric service provides enough amps. Using this guideline will prevent long term issues and help protect investment. Do the main breaker stress test

Inside Main Breaker BoxQuestion:
Can I put 190 amps on one leg, and 5 amps on another leg?
Answer: No.
This can cause imbalance issues in the transformer.

It would be difficult to accidentally put 190 amps on one leg and 5 on the other. Why? When a double breaker is stabbed into the panel, it draws a Hot from each busbar because every other breaker slot goes to a different leg on the busbar. So all double breakers are automatically balanced, and draw equally from both busbars.
Single breaker: If you put all the single breakers on one side of the panel, every other breaker will draw from a separate busbar and so the load is balanced. This assumes you don't install 15 amp breaker every other slot, and 30 amp on the other slots ... because that would draw unevenly from both busbars.

Ideally in a residential breaker panel, single breakers should be evenly divided, with roughly half on one side and half on the other. The double breakers are snapped over both busbars so their location is unimportant for 'balancing the loads.' Leave top two breaker spaces, located closest to main breaker, on either side of panel for installing Type 1-2 surge protection device.
Type 1-2-3 surge protectors


If the residential breaker panel is somehow unbalanced, this can cause damage to motors, HVAC etc. The problem of imbalance is usually found in commercial 3-phase installations where 'voltage monitors' are used to protect vulnerable circuits from imbalance issues.
A voltage monitor can protect household HVAC from low voltage or brownout events.
How to wire voltage monitor

More info:
Residential breaker box has 2 Hot busbars. Each busbar is 'out-of-phase' from the other busbar. Each busbar has 120 volt potential to Neutral (phase voltage) and 240 volt potential to the other busbar (line voltage). 240 volt breaker snaps over both Hot busbars, while single-pole breaker snaps over one Hot busbar. The breaker box should not be overloaded on one busbar, or one leg.
Unbalanced load can unbalance the transformer and electricity might not have the correct waveform, causing damage to motors, electronics etc.

Resource:

What does out-of-phase mean
Troubleshoot household electric
See inside main breaker box
Basic household wiring diagrams
Question:
Can I reverse feed a circuit breaker and have it work?

Answer:
Yes, most molded-case circuit breakers can be reverse fed and they work fine.
However, if the circuit breaker has LINE and LOAD embossed or printed on each end of breaker, then it cannot be reverse fed.


Resource:
Reverse feed breakers .pdf
Single-phase water heater amp draw
Larger image
Refer to chart above.
1500 watt element.
12.5 amp @ 120 volt
or 6.3 amp @ 240 volt
So the amp rating drops by 1/2 for same wattage load.
This means that 240 volt breakers are designed to handle large appliances that cannot be supplied by 120 volt.
To illustrate how much more power 240 volt supplies to an appliance, we use the 4500 watt element with a rating of 240 volt.
When connected to 240 volts 30 amp double breaker, the element heats 16+ gallons per hour.
When same rated element is connected to 120 volt, it heats 1/4 the amount of water per hour, and a smaller breaker can be used.
Resources:
Figure volts amps watts
Formulas for ohm's law
Match breaker and wire size
circuit breaker resources Circuit breaker resources
Water heater is tripping breaker
How to replace circuit breaker
How to wire gfci
Can AC breaker be used for DC breaker
How to reset circuit breaker
Not enough space for circuit breakers/ use tandem
Circuit breakers
How to install subpanel
Why you need ground wire
See inside breaker box
How to wire safety switch
How to wire whole house surge protector
Figure volts amps and watts
Figure correct wire and breaker
Types of surge protection

Multimeter
Test for breaks in wire/ Test for voltage
Most appliance require 80% rated voltage to function correctly
Buy
Analog multimeter
Multimeters at Amazon
Klein multimeter
Electric testers at Amazon
Clampmeter for testing amp flow on line
Resource:
How to test and replace element
How to test thermocouple
Element tests for 120 volts
How to test wire

Safety when testing wires:
Never touch wet or previously flooded appliance.
Never stand on wet surface when working on electric.
Never stand on bare soil, put down dry boards.
Tape tester leads to wood sticks to keep hands away from power.
Use non-contact voltage tester before touching wires.
Never touch or lean into any made of metal.
Remove metal objects from pockets.
Do not use oxygen or fuel accelerants in same room as electrical repairs

Resource:
Basic house wiring
GFCI receptacle120 volt 15 amp devices including GFCI, timers, switches, plugs, wifi controls etc can be installed on 15 or 20 amp breaker.

120 volt GFCI, outlet, receptacle that is rated 20 amp can be installed on 20 amp breaker only, but NOT on 15 amp breaker.  
Buy
15 amp GFCI
20 amp GFCI
Southwire armored cable cutter
Electrical tools must be insulated.
Always best to disconnect power, but insulation failure, lack of proper grounding, grounded neutral, lack of GFCI, out-of-code wiring, generator operating without transfer switch, and other problems still pose a risk to anyone working on electric power ... even when breaker is off.

Buy:
Electrician tools kits
KLEIN TOOLS
Tools kits
IRWIN tools
KNIPEX
6x6x4 pull box
6" Pull box
Junction boxes for conduit and wiring
Buy:
Bud industries 6x6x4 best value/ no KO
Raco 6x6x4 metal pull box
Wiegman 6x6x4 pull box
Hoffman 6x6x4 pull box
Adamax raintight enclosure
Raintight 6x6x4 box
Pull boxes
Buy:
Pull boxes
Polycarbonate boxes
Resource: Enclosures and boxes
Terminals

Terminals

Buy:
Crimping tool kit
Blue for 16-14 wire
Yellow for 12-10 wire
Ratcheting Crimper

Resource:
How to install terminal

Use nipper instead of pliers or screwdriver for removing staples (and nails). Do not damage cable or wires inside cable.

Code
-Cable SHALL BE secured without damage to the outer covering. NEC sec. 336-15
Buy
End cutting nippers at Amazon

 


When removing insulation from wire, do NOT score or put cuts on surface of copper wire. Doing so increases resistances on wire and creates weak point.
Buy tools:
Wire strippers at Amazon
Linesman pliers
Pro linesman plier
Needle nose pliers
End cutting nippers at Amazon

How to wire contactors/ relays
Busman HKP-HH fuse holder
How to wire inline fuseholder
AH3 off delay timer
How to wire delay timers
How to wire twin timers




Buy
Tools
Milwalkee
DEWALT
Black and Decker
Stanley
SKIL
Makita
Porter-Cable
Bosch

Irwin Hand tools
Klein hand tools
Fluke electrical testing
Dremel hobby tools

Campbell Hausfeld air powered
Tekton automotive

Powerbuilt automotive
Saws and saw blades

Buy from my affiliate links every time/ thanks:
Amazon
''As an Amazon Associate I earn from qualifying purchases''
Enter Amazon from any link on my site, fill cart with any item ... purchases pay small commission

E-mail: geno03245w@gmail.com
My response might end up in spam folder, check email folders
Waterheatertimer on Twitter
Message thru facebook
>