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Basic 240 & 120 volt water heater circuits

Electric water heaters are resistive loads with power factor of 1
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
White 14 gauge 15 amp
120 volt 15 amp outlet, AFCI, GFCI, timer, switch etc can be installed on 15 or 20 amp breaker. Never connect 15 gauge wire to 20-30-40 amp breaker.

White/ #14 gauge wire,  with ground ... 15 amp capacity. Safe maximum 12 amps.
Buy:
14-2 gauge/ 15 amp
14-3/ 15 amp

NMB is house wiring
UF is underground
50-60 amp breaker use 6 gauge /
240 volt 50 outlet can be installed on 50 amp breaker only
6-2 wire
Buy:
6-2 wire
Southwire electric tools
NMB is house wiring
UF is underground
40-50 amp breaker use 8 gauge /
240 volt 40 amp outlet can be installed on 40 or 50 amp breaker only
6-2 wire
Buy:
8-2 wire
Southwire electric tools
NMB is house wiring
UF is underground
     
Copper ground wire.
Every device, load, metal enclosure etc must be grounded. Ground wire must be continuous throughout installation, never switched on-off, never used as a Neutral wire.
Generally ... use same size as other wire in circuit
Buy:
12 gauge copper ground wire
Ground wire
Green ground wire
Ground pigtails
Ground rods/ ground clamps at Amazon
armored cable
Non metallic flexible cables must carry ground wire, but do not have hazard of short circuit causing injury from shock.

Armored steel cable can be used as a grounded connection, and will protect wires from damage. Metal can be energized from an insulation failure.

All conduit ...metal, plastic ... flexible and rigid ... must be attached to structure, and attached to enclosures, boxes.
Movement, damage and deterioration are major cause of electrical failure.
Buy:
Non-metallic flexible conduit
Power whip
Armored cable
Southwire armored cable cutter
Pull boxes
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
stranded wire
600 volt 12 ga Stranded wire ot THHN wire is good for conduit with multiple wires ... but stranded cannot be installed under screw terminals on outlets, switches, timers etc without risk ... of heat causing splayed strands ....that come loose ... and begin to arc. Connect stranded to short piece of solid copper wire, and attach solid to screw terminal. Do not solder residential or commercial wiring.

Project wire, extension cords, thermostat, bell and automotive wire are not rated for residential or commercial wiring. Only wire marked 600 volt can be used for permanent household wiring.
Buy:
Southwire 600 volt stranded wire
Rolls of stranded wire
HOOK UP Wires

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

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


Electrically insulated tools
When removing insulation from wire, do NOT score or put cuts on surface of copper wire. Doing so increases resistance and heat on wire and creates possible weak point.
Buy tools:
KLEIN TOOLS
Wire strippers at Amazon
Electric Wire Stripping Machine
Linesman pliers
Utility knife at Amazon
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
Dia 1) Typical residential water heater: 240 Volt 4500 watt:
Black and White wires are hot > bare copper is ground
240 volt water heater circuit
30 amp 10 gauge wire supports up to 5500 watt non-simultaneous water heater
       
When using black-and-white wires for 240Volt, add tape to white wire.
This action will tell next electrician that white wire carries power.
Connect either wire to either wire



Breaker box
Meter on water heater
Use kWh hour meter to record usage of water heater.
This is most accurate way to determine what percentage of bill is going to water heater over a full month. Take only showers for a week see what it costs per shower vs bath ... observe hot water usage for laundry etc.
To connect meter: Temporarily disconnect wires from top of heater. Install meter on two jumper wires. Use jumpers to temporarily reconnect power to water heater. Cover with tape to secure temporary connection. Add conduit and junction box if meter is to be installed for any length of time.
Buy
240 volt pass through kWh  meter

Resource:
How many kilowatts to heat water
Water heater causing high electric bill
Meter on water heater
The kWh meter is din rail mounted inside enclosure.
Track exact usage

Connect either wire to either wire. Black to black and white to red is my technique, but it works either way..
 
Buy
Bomain power meter
Ketotek power meter
240 volt pass through kWh  meter
2T2502GA beige plastic enclosure
2T2500GA grey plastic enclosure
din rails
Resource:
Enclosures
Figure volts amp watts for water heater
Dia 2) Typical residential water heater: 240 Volt 3500 watt

240 volt water heater circuit
20 amp 12 gauge wire supports up to 3800 watt non-simultaneous water heater

Read label on side of water heater.

Using 12 gauge wire on 4500 watt water heater can overheat wire and breaker, causing shortened breaker life and possible damage to breaker busbar

Using 12 gauge wire on 5500 watt water heater will blow breaker

Resources:
Figure volts amps watts for water heater
Choose correct wire and breaker size
Water heater is tripping breaker
Dia 3) 3-wire 240 Volt circuit with neutral wire: uncommon
Not typically found in residential water heater circuits
Black and Red wires are hot > bare copper is ground > white is neutral
240 volt water heater circuit 
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Resources:
How to wire thermostats
How thermostats work



Dia 4) 120 Volt water heater circuit: for under counter water heater
Typical example of under-counter water heater
Black wire is hot > white wire is neutral > bare copper is ground
120 Volt water heater circuit
Resources:
Water heater will work on any voltage as long as element voltage matches supply voltage
Convert 240V water heater to 120V
Connect water heater to generator
color-code household wire
Resource:
Wire sizes


Main breaker
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Residential Main panel has 120 and 240 volt circuits.
This is called single-phase electric power. Phasing is determined by the power company transformers.

-Each 120 volt circuit can include up to 12 outlets, and supply power to lights inside a room.
- Generally each 120 volt circuit sends power to one area of home. This is because the wire leaves breaker box and goes to first junction box inside a room. From the junction box, the wire splits off and goes to each individual box, jumping from box to box until the final box is reached. So each box will have 1 black hot wire, 1 white neutral wire, and 1 ground wire that connect back to main breaker box.
- Some circuit breakers are dedicated to 1 specific appliance. For example the kitchen microwave is usually wired to 1 circuit breaker and no other outlets or lights are connected to that breaker. This is because microwave draws so much amperage. That is called dedicated circuit, and dedicated breaker.

- Each 240 volt circuit is usually dedicated to one appliance. For example electric water heater is connected to 1 240 volt breaker. The electric dryer is connected to another 240 volt breaker. The heat/AC is connected to another 240 volt circuit breaker, and so on.
Resources:
See inside main breaker box
How to replace circuit breaker
How to install subpanel
Figure volts amps watts for electric water heater
Difference between single-phase and 3-phase
Timer installed on water heater

Buy
T104 240 volt timer

Resources
240 volt T100 series timers
Compare all timers

Control water heater with 30 amp switch
Control water heater with Zwave
Control water heater with remote switch
Control water heater with WEMO

Toggle water heater and car charger

30 amp safety cut off Fused safety switch
Cuts power to one or both legs of 240V circuit.
Rated for indoor.
-3 Hp motor, 17 amps, use 30-60 amp safety switch
-30 amp water heater, use 30-60 amp
Since water heater is on a breaker, then either fusible or non-fusible is fine
Buy from my affiliate links:
L211N 30 Amp 120/240-Volt/ 30A /one plug fuse
L221N 30 Amp 240-Volt/ 30A/ two plug fuses
As illustrated
2-pole outdoor / 60 amp/ non-fusible
2-pole outdoor / 30 amp/ non-fusible

2-pole indoor / 30 amp/ fusible
2-pole indoor / 30 amp/ fusible

Heavy duty safety switches at Amazon

Resource:
L111N specs Single pole 30 amp 120 volt w neutral/ indoor
L211N specs Double pole 30 amp 120/240 volt w neutral

L211N Fusible
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Electrical problems
-Heat means electric loss. -Hot breaker: put hand on each breaker to feel if it is warm or hot -Undersized wire and breaker: 4500-5500 watt water heater requires 30 amp breaker and 10 ga wire up to 150 feet away from main breaker box. Use 40 amp and 8 gauge wire over 150 feet.

Resources:
Figure volts amps watts for water heater
Match breaker and wire size
Water-heater-is-blowing-breaker
Stress test breaker panel
How to replace circuit breaker
Water heater causing high electric bill

Electricity from pole to breaker box


How to install Subpanel
Electricity is a wave that oscillates at 60 cycles per second. This is called 60 Hz.which appears on electric device labels.

120 volt is like pedaling a bike with one leg. 240Volt is like pedaling bike with 2 legs.
Commercial 3-phase is like pedaling a bike with 3 legs.

Household power is called single-phase or split phase.
Electricity from power plant to distribution substation
What is 3-phase electric: power plant to end user
Electricity:
The grid is defined by three parts: transmission, distribution and end user. The following links show how it works
Power plant to end user power pole
Power pole to residential breaker box
Power pole to commercial breaker box

How to wire basic home electric
How to wire commercial 3-phase

Why you need ground wire
How to wire 3-phase timer
3-phase water heater




Buy
Tools
Milwaukee
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

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