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How to wire safety switch
Resource: safe electric wiring
Safety switches are used to cut power to equipment such as HVAC, lathe, compressor etc
There are two types of safety switches: Fused and Non-fused
Outdoor safety switch
Indoor
Non-fused safety switch
Cuts power to both legs of 240V circuit.
Rated for outdoor.
-3 Hp motor, 17 amps, use 30-60 amp safety switch
-30 amp water heater, use 30-60 amp
Buy from my affiliate links:
2-pole outdoor / 60 amp/ non-fusable
2-pole outdoor / 60 amp/ non-fusable
2-pole outdoor / 30 amp/ non-fusable
Heavy duty safety switches at Amazon
30 amp safety cut off
Indoor
fusable safety switch
OK to have more than one fuse on same line.
If you have circuit breaker, then it is ok to install fusable safety switch -or- non-fused
Always match fuse amp rating to load amps.
Buy fusible:
L111N 120 volt only/ 1 plug fuse
L211N 30 Amp 120/240-Volt/ 30A
L221N 30 Amp 240-Volt/ 30A
2-pole indoor / 30 amp/ fusable
2-pole indoor / 30 amp/ fusable
LF211N 30 Amp  PLUG Fused
Safety switches at Amazon
Resource:
L111N manual Single pole 30 amp 120 volt w neutral/ indoor
L211N manual Double pole 30 amp 120/240 volt w neutral
L221N manual Double pole 30 amp 240 volt w neutral/ indoor
Match wire and breaker size
LN221N 2-pole manual
LN111N 1-pole manual
LF211N spec sheet
GF211N 2-pole label
3-pole 30 amp outdoor safety switch
Outdoor
3-pole 240 volt non-fusable safety switch

Buy:
3-pole/ outdoor/ 30 amp/ non-fusable
3-pole 30 amp non fusable
3-pole/ outdoor/ 60 amp/ fusable

A 3P or 3-pole safety switch is used for 3-wire 3-phase power ... but can be used for 2-wire single phase residential or commercial 208-240 volt.
By code, the Neutral wire, when present, is not switched on-off, and must remain continuous throughout home or building.
3-pole 100 amp indoor safety switch
Indoor
3-pole 240 volt non-fusable safety switch

Buy:
3-pole/ indoor/ 30 amp/ non-fusable
3-pole/ indoor/ 30 amp/ non-fusable
3-pole/ indoor/ 30 amp/ non-fusable
3-pole/ outdoor/ 60 amp/ non-fusable
3-pole/ 600 volt/ 60 amp/ non-fusable
outdoor 30 amp fusible safety switch
Outdoor
fusable safety switch
Buy:
2 pole/ outdoor/ 30 amp/ fusable

Resources:
Figure volts amps watts
Figure breaker and wire size
Safety switches at Amazon
60 amp safety switch
Indoor
fusable safety switch
Buy:
2-pole / 30 amp heavy-duty
2-pole/ indoor / 60 amp/ fusable
2-pole/ indoor/ 100 amp / fusable
2-pole indoor / 100 amp/ fusable
Safety switches at Amazon
3-pole non-fusible safety switch
Outdoor
3-pole 600 volt non-fusable safety switch
Heavy duty 600 volt

Buy:
3-pole/ outdoor/ 30 amp/ non-fusable
3-pole/ outdoor/ 60 amp/ non-fusable
3-pole/ outdoor/ 100 amp/ non-fusable
Safety switches at Amazon
Heavy duty safety switches at Amazon
Resource:
Leviton safety switch/ pdf

DC safety switch
Non-fusable
DC safety switch 250 Volt
DC safety switch outdoor

Buy:
3-pole / outdoor/ 30 amp DC/ non-fuse
Square D 60 amp DC H222AWK
Square D 30 amp DC HU361RB

DC circuit breaker
Resource:
GF211N spec sheet and label
non-fusable pull out
Outdoor
Non-fused/ Pull out disconnect
Cuts power to both legs of 240V circuit.
Code for AC units
Rated for outdoor
2-finger pull-out cuts power to both legs of 240V circuit.
No fuse.
Buy:
2 pole/ outdoor/ 60 amp/ fusable
2 pole/ outdoor/ 60 amp/ non-fusable
2-pole/ 60 amp w 20 amp GFCI outlet
Pullout Disconnects at Amazon
Rotary disconnect
Wiring
fusible pull-out
Outdoor
Manual pullout/ fused
No switch lever
Manual pull-out disconnect
Buy:
2 pole/ outdoor/ 30-60 amp/ fusable
60 amp cartridge fuse
50 amp cartridge fuse
30 amp cartridge fuse
Pullout Disconnects at Amazon

If you have 240 volt, 50 amp AC unit, then use two 50 amp fuses.

600 volt motor switch
30 amp DPST toggle switch
Cuts power to both legs of 240V circuit.
Motor cut-off switch
30 amp/ max 600 volt

Buy:
30 amp DPST switch
Leviton 30 amp DPST
3-pole 3-phase motor starter
Motor starter switch and cover

Resources:
Figure volts amps watts
Figure breaker and wire size
600 volt 3-phase motor switch
3-phase 30 amp 3PST toggle switch

3PST = 3 pole single throw
3-pole safety switches are 3PST
Rated 30 amp/ max 600 volt
3-phase Motor cut-off switch
Power can connect to either side
Match phase to phase on screw located on opposite side
Buy:
3-pole 3-phase motor starter

600 volt motor start switch

power tool safety switch
Paddle switch/ safety switch for power tools
Raise red cover before tool can be activated.
Quick shut-off by pushing down red lever

Buy:
Safety switches for power tools
Rotary disconnect


AC current is different than DC
AC current reverses direction once each 50-60 seconds because of how AC power is generated. Read more
When AC changes direction, the voltage drops to zero 50-60 times each second.
When voltage drops to zero, the arc is easy to extinguish using AC-rated switches.

600 Volt AC-DC AL CU
CH362 Type 1
CH362AWK Type 12
CH362RB Type 3R
CH362DS Type 4X

Safety switch maintenance
General duty specs





DC power is different.
Generally, for this explanation, DC stays at the same voltage at all times.
DC never drops to zero volts like AC.

When you want to switch off DC, there is a larger arc, that is more difficult to extinguish.
Basically the electrons in DC power keep pushing forward at all times.
This forward motion of DC electrons maintains the arc longer, and can cause damage to electrical equipment that is not rated for DCRated 250 volt DC
120-240 v FUSIBLE
LF111N 120 v 30A plugged fuse
LF211N 240 V 60A plugged fuse
GF211N 240 V 60A 3P cart fuse

240 volt 3-phase Safety Switches
D321N
D321NRB

60 amp
D3222N
D322NRB

fuse puller
H321N
H321NRB  60 AMP
https://amzn.to/3vGKfS6

H322N
H322NRB

1.5 hp 240 V at AC 60 Hz for 1 phase conforming to NEC 240.6

3 hp 240 V at AC 60 Hz for 3 phase conforming to NEC 240.6

3 hp 240 V at AC 60 Hz for 1 phase conforming to NEC 430.52

7.5 hp 240 V at AC 60 Hz for 3 phase conforming to NEC 430.52

HNF362 60-Amp 3 Pole 600-volt 3 Wire Non-Fused Heavy Duty Safety Switches
https://amzn.to/3i72f49

HNF362 60-Amp 3 Pole 600-volt 3 Wire Non-Fused Heavy Duty Safety Switches
https://amzn.to/2S1PnSr

HNF361 30-Amp 3 Pole 600-volt 3 Wire Non-Fused
https://amzn.to/3uEGiMo

HNF363 100-Amp 3 Pole 600-volt 3 Wire Non-Fused
https://amzn.to/3vDuHyM
Square D Fusible
Light Duty 120 volt

L111N Single pole 30 amp 120 volt w neutral/ indoor
https://amzn.to/3fF0Eko
L211N Double pole 30 amp 120 volt w neutral
https://amzn.to/3wMXHUN

Light Duty 240V
L221N Double pole 30 amp 240 volt w neutral/ indoor
https://amzn.to/3fD07j5
General Duty 120 volt
D211N Double pole 30 amp 120 volt w neutral/ indoor

D211NRB Double pole 30 amp 120 volt w neutral/ outdoor
https://amzn.to/2SNV2LG
D221NCP
https://amzn.to/3g0EaJS
General Duty 240 volt
D221N Double pole 30 amp 240 volt w neutral/ indoor
https://amzn.to/3c88KA6
https://amzn.to/3uDqv0z
D221NCP
D221NRB Double pole 30 amp 240 volt w neutral/ outdoor

https://amzn.to/3vIvajg
D222N Double pole 60 amp 240 volt  w neutral/ indoor
D222NRB Double pole 60 amp 240 volt w neutral/
outdoor

GNF222RA
https://amzn.to/2Tvi5eS
D323NRB 100 Amp 3-phase 240 volt
https://amzn.to/2SKWJtk

D324NRB 200-Amp 240-volt 3-Pole
https://amzn.to/3uHVyZ4

Manual
Resource pdf
These switches accept the "Edison Base" plug type fuses.

Heavy Duty AC/DC voltage
H221N Double pole 30 amp 240 volt AC w neutral/ 250VDC Indoor
H221NRB Double pole 30 amp 240 volt AC w neutral/ 250VDC outdoor

H222N Double pole 60 amp 240 volt AC w neutral/ 250VDC  indoor
H222NRB Double pole 60 amp 240 volt AC w neutral/ 250VDC  outdoor
30 amp safety cut off     30 amp DC safety switch 30-Amp 120-240-volt Two-Pole Indoor Safety Switch with Neutral/ fusable
Safety switch is important.
Often the circuit breaker panel is locked, or located remotely.
Safety switch, or power cut-off, is installed next to air conditioner, or water heater, or other appliance.
Code often requires fused or unfused safety cut off next to air conditioner or any outdoor appliance
When safety switch is OFF, person is more certain power is OFF.
ALWAYS check if power is actually off before working on appliance.  
NEVER stand on bare ground when touching electrical device... stand on dry boards until power is OFF for certain.

Buy from my affiliate links
2-pole 30 amp non-fusable safety switch/ indoor / power cut-off
2 pole 60 amp non-fusable / outdoor box/ at Amazon
Safety switches at Amazon
Safety switches for power tools

Resource:
You can use fusable or non-fusable
Having more than one fuse or breaker on same line is ok by code
Never assume power is OFF: Use Non-contact voltage tester
Test for power without touching wire
NEVER assume power is OFF
Press button. tester beeps once, and blinks once, when power is OFF.
Tester beeps continually and blinks when power is ON
Buy:

Non-contact voltage tester Amazon
Electric testers at Amazon
Multimeter
Test for breaks in wire/ Test for short circuit/ Test for voltage/ Test if voltage is present
Most appliance require 80% rated voltage to function correctly
Tape tester leads to wood sticks to keep hands away from power.
Never stand on wet or damp surface
Never stand on bare soil... or ground
Always stand on dry boards
Remove metal from pockets, do not lean into or touch anything made of metal
Buy here and support DIY:
Multimeters at Amazon
Electric testers at Amazon
How to wire safety switch
Larger image
bonding lugs
Use correct size screwdriver when connecting wire to bonding lugs
Tighten very tight against copper wire.

If using Aluminum wire (not advisable to use aluminum) make sure the safety switch is rated for CU-AL. Typically, CU-AL rating requires allan wrench to tighten lugs, and not a screw.

Allen wrench will give more torque on the screw so it will tighten firmly and not move.

Larger wire sizes have allen wrench screw for correct torque on the wire
Code says: Use connected/ double-pole breaker
Against code: Use 2 single breakers to supply 240 volt, unless the switches are connected and rated for same amps.

If breakers are connected, then if one side (leg) trips the other side usually trips off too. 
If breakers are NOT connected, then one leg might be tripped, and other leg not tripped.
A double breaker that is tripped on one leg poses a threat if working on the circuit. Never assume power is OFF. To reset, push fully off then back on.

If double breaker is rated for 30 amp, then BOTH sides of the breaker are each 30 amp (not 15 each)
Power is doubled with 240 volt vs 120 volt, amps are not halved.
Resource: 240 volt breaker keeps tripping
Use only 600 volt solid copper wire for household wiring

Rolls of 600 volt stranded wire seem inviting, and have wide choice of colors, but are not best choice for screw terminals and screw lugs ... because stranded wire comes loose with the heat from a load, and loose connection will start to short and burn out, melting the terminal and lug etc

Household NM-B Wires are color-coded so inspectors/ electricians can easily identify which wire is used during construction

If your home was wired by professional electrician who pulled permits, then circuit breaker and wire size will match. If manufactured home or travel trailer has not been altered by homeowner then breaker and wire size will match.

If breaker is oversized for wire... fire danger
Breaker can let too much amperage travel through the wire. Wire can overheat and cause fire.
Call electrician if you suspect wiring is not correct,

Buy:
Southwire at Amazon
Resource:
How to select wire and breaker
30 amp DC safety switch   30 amp DC safety switch 30-60 amp DC safety switch/ fusable/ outdoor
Heavy Duty 250 V Dc Voltage; 60 Ampere
Use 10 gauge wire with 30 amp fuse
Use 6 gauge wire with 60 amp fuse
Buy:
Square D 60 amp DC H222AWK
Square D 30 amp DC HU361RB
30 amp DC 240 volt 600 Volt
3-pole safety switch
Larger image
3-pole safety switch
Example shows fusable/ this is called a 4-wire, but only 3 wires are disconnected by safety switch
It is OK to have breaker and fuse on same line.
More than 1 fuse, and more than 1 breaker on same line is OK.
If load has breaker it is not necessary to use fusable safety switch. You can use non-fused safety switch.

Disconnect rating must be at least 125% of the ampere load...and within sight of the unit...and with ability to lock in open (off) position
If load is 30 amp, then buy safety switch rated for 30 x 125% = 45 amp, so buy safety switch rated for 60 amp
If load is 2o amp, then buy safety switch rated for 25 amp, so buy safety switch rated for 30 amp.
The rating on the safety switch is MAXIMUM amp rating... 60 amp safety switch will handle loads up to 60 amp.
lug connection
Fuse must match Load.
Always install fuse that is rated same as amp load.
If load is 30 amp, then install 30 amp fuse and 10 gauge wire.
If load is 20 amp, then install 20 amp fuse and 12 gauge wire

Carefully label safety switch

Buy:
3-pole/ indoor/ 60 amp/ fusable
3-pole 30 amp safety switch/ fusable/ at Amazon
3-pole 60 amp safety switch/ non-fused/ at Amazon
3-pole 60 amp safety switch/ fusable/ at Amazon

Resources:
Match wire and breaker size
Figure volts amps watts for water heater
How to wire 3-phase
What is 3-phase

Commercial three-phase power comes in variety of standard voltages and transformer configurations. Typical 120-208V WYE service and 277-480V WYE service use red-black-blue wires for easy identification. Other services like 120-240V high leg DELTA use black-black-orange wires for easy identification.

Commercial three-pole safety switches can be found at the service entrance, and at any piece of equipment that is not in direct sight line with breaker box such as air conditioner, 3-phase water heater, 3-phase motors and machinery etc. Multiple fuse and breaker protection on one line is not a problem.

Safety switch that is rated 240V can be used for 120-208-240V. Cannot be used for 480V.
Safety switch that is rated 600 volt can be used for any voltage 120V through 600V.
review techluck
Larger image
Example 3-pole safety switch application

disconnect...at least 125% of the ampere load...within sight of the unit...and with ability to lock in open (off) position
Two different voltages arrive at water heater
Household 240 Volt AC power feeds upper element, with 2 hot wires
120 Volt AC from Solar panels feeds lower element, with Hot and neutral
Total 3 hot wires.... use 3-pole safety switch
Carefully label safety switches so people know both switches must be turned off for water heater to be OFF

Buy:
3-pole 30 amp safety switch/ fusable/ at Amazon
3-pole 60 amp safety switch/ non-fused/ at Amazon
3-pole 60 amp safety switch/ fusable/ at Amazon

Resource:
Review Techluck
PV safety switch Example DC safety switch for solar array
Use fused or non-fused
This is one way to use safety switch
Purpose of safety switch is to ensure all power is OFF
The handle is clearly visible and can be latched in place
Locate safety switch in plain sight so people can clearly identity when power is OFF
Remember, a solar panel will produce electricity each time it is exposed to light.
You can get shock from solar panel when panel is exposed to sun.
The array and safety switch must be wired at night

The strings can be combined before connecting to safety switch... match total volts and amps with safety switch rating and with fuse rating
When three panels are wired together, the positive wire connects to negative wire to make a string.
Solar panels are like batteries.
When three panels are connected in series, or in a string, then voltage increases with each additional panel, but amperage stays the same.
Illustration shows 3 strings with 3 panels in each string.
If the strings are combined together in parallel, then the voltage stays the same but amperage increases.
Maximum voltage for wire and safety switch is 600 volts AC/ 300 volt DC

Resources:

Calculate volts and amps for array/ How to set up array
DC safety switch wiring/ pdf

Schneider safety switch wiring for DC/ pdf
Schneider safety switches/ pdf
4-pole DC breaker Example DC safety switch for solar array
Use fused or non-fused
Wired in series..
Positive + side is routed through 3 cut-offs
Negative - side is routed through 1 cut offs
Safety switch hub Safety switch hub
Installing subpanel Resources:
How to wire subpanel
See inside main breaker box
What is 3-phase electric: power plant to end user
How to wire 3-phase timer
Light duty/ AC and DC
How to wire safety switch
How to wire safety switch
How to wire safety switch
How to wire safety switch
Heavy duty/ AC and DC
How to wire safety switch
How to wire safety switch
How to wire safety switch
How to wire safety switch
Class R fuses 600 volt AC @ 30 amp fuse/ 300 volt DC @ 15 amp
600 volt AC  @ 600 amp/ 120 volt DC @ 60 amp
6000 volt AC @ 6000 amp/ 300 volt DC 2000 amp
Time delay fuse passes surge currents without sacrifice short circuit limitation
Buy:
Class R fuses at Amazon
Bussman LPN-RK-SP heavy amp AC-DC fuses at Amazon
Bussman 600 Vac @ 200 amp/ 300 Vdc @ 100 amp/  at Amazon
Bussman 250VAC/250VDC @ 25 amp
30 amp Cartridge fuse
Bussman fuses at Amazon

Resource:
Bussman fuses/ pdf
Use 10 gauge wire with 30 amp fuse
Use 6 gauge wire with 60 amp fuse

Resource:
Match wire and amp rating
Class R fuses Bussman DC fuses
Buy:
60 amp DC cartridge fuse
50 amp DC cartridge fuse
40 amp DC cartridge fuse
35 amp DC cartridge fuse
30 amp DC cartridge fuse
25 amp DC cartridge fuse
20 amp DC cartridge fuse

70 amp DC cartridge fuse
90 amp DC cartridge fuse
80 amp DC cartridge fuse
125 amp DC cartridge fuse
150 amp DC cartridge fuse
175 amp DC cartridge fuse
200 amp DC cartridge fuse
225 amp DC cartridge fuse
250 amp DC cartridge fuse
300 amp DC cartridge fuse
350 amp DC cartridge fuse
600 amp DC cartridge fuse

Resources:
DC safety switches
photovoltaic fuseholder Fuseholder/ AC/DC fuseholder/
rated 1000 volts DC/
Not waterproof... mount inside Nema 3R enclosure
Mount on din rail/ change fuse with flick of finger
Install 25-30 amp fuses
Use 10 x 38 DC fuses
Use ordinary wire size/ 20 amp and 12 gauge wire, 30 amp and 10 gauge wire

Buy
Photovoltaic fuseholder / DC fuseholder/ ultrasafe/ at Amazon
Ultrasafe fuseholders at Amazon
Fuseholder + 15 amp fuse
DC fuse pack/ $9
Buy
10 pack 1000 VDC 15 amp
100 pack 1000 VDC 15 amp
Fuseholder and 15 amp fuse
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.

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
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

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