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Air ConditioningAir Conditioning

Breaker Panels and Disconnects

Breaker Panels and Disconnects

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Breaker Panel Breaker Panel

Function:• Distribute electricity to individual

circuits • Each branch has rated amperage • Breakers must be reset by hand • Main breaker will control voltage

to whole panel

Function:• Distribute electricity to individual

circuits • Each branch has rated amperage • Breakers must be reset by hand • Main breaker will control voltage

to whole panel

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Construction Construction • Panels can be built with or

without main breaker • Rated for amperage

– How many amps the main lug can handle

– Amps the main breaker can handle

• Phase – Single – Three

• Panels can be built with or without main breaker

• Rated for amperage – How many amps the main lug can

handle – Amps the main breaker can handle

• Phase – Single – Three

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• Neutral strip with screws • Ground strip with screws • Each breaker should be

marked • Lock out for safety

• Neutral strip with screws • Ground strip with screws • Each breaker should be

marked • Lock out for safety

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• Breakers will be: – Single pole – Double pole – Three pole

• Styles are snap in or clamp on • Can be in “On”, “Off” or

“Tripped” position.

• Breakers will be: – Single pole – Double pole – Three pole

• Styles are snap in or clamp on • Can be in “On”, “Off” or

“Tripped” position.

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• When breaker is tripped, handle will usually move halfway between on and off position, or a red mark will appear.

• To reset, breaker must be moved to off position, then back on.

• When breaker is tripped, handle will usually move halfway between on and off position, or a red mark will appear.

• To reset, breaker must be moved to off position, then back on.

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Disconnect Switches Disconnect Switches • All system should have another

means to disconnect power • Should be within service mans

reach • Can be mounted to the outside of

the unit • Uses double pole double throw to

208/240 applications • Uses single pole single throw for

120volt

• All system should have another means to disconnect power

• Should be within service mans reach

• Can be mounted to the outside of the unit

• Uses double pole double throw to 208/240 applications

• Uses single pole single throw for 120volt

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• Can be fused or non-fused depending on application

• May be have lever or pullout

• Can be fused or non-fused depending on application

• May be have lever or pullout

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Types of Wiring Types of Wiring

1.EMT2.Greenfield3.Seal-tite4.Romex5.BX6.MC 7.Knob and Tube

1.EMT2.Greenfield3.Seal-tite4.Romex5.BX6.MC 7.Knob and Tube

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Types of Wiring Types of Wiring 1. Electrical Metallic Tubing (EMT): rigid

galvanized metal conduit that can be bent and have wires run through it.

1. Electrical Metallic Tubing (EMT): rigid galvanized metal conduit that can be bent and have wires run through it.

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• Greenfield: Flexible metallic conduit, no wires inside; wires provided by installer.

• Greenfield: Flexible metallic conduit, no wires inside; wires provided by installer.

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• “Sealtite” flexible conduit : Used outdoors to provide weather proof connection from A/C condensing unit to disconnect switch.

• Can be purchased as a “whip”, usually 6’ long with wires inside.

• “Sealtite” flexible conduit : Used outdoors to provide weather proof connection from A/C condensing unit to disconnect switch.

• Can be purchased as a “whip”, usually 6’ long with wires inside.

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Seal-titeSeal-tite

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• Romex: Trademarked name of NM (non metallic) cable- Wiring typically found in residential indoor applications. Solid wire, plastic sheathing.

• Romex: Trademarked name of NM (non metallic) cable- Wiring typically found in residential indoor applications. Solid wire, plastic sheathing.

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• SJ cord: stranded copper wire, rubber insulated, for use with portable tools and equipment.

• SJ cord: stranded copper wire, rubber insulated, for use with portable tools and equipment.

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• BX: generic term for flexible metallic conduit with wires inside, but no ground wire, sheathing itself was used for ground conductor.

• BX: generic term for flexible metallic conduit with wires inside, but no ground wire, sheathing itself was used for ground conductor.

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• MC (Metal Clad) cable: flexible metallic conduit, has wires inside, including insulated ground wire. More durable and resistant to damage than Romex.

• MC (Metal Clad) cable: flexible metallic conduit, has wires inside, including insulated ground wire. More durable and resistant to damage than Romex.

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• Knob and tube: Wiring found in very old homes. Can not be used, must be upgraded by electrician.

• Knob and tube: Wiring found in very old homes. Can not be used, must be upgraded by electrician.

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