Hvac circuit breakers and fuses

AIC

Needs to react quick

If a contact is rated at 20A the fuse should normally be

No larger than the protected circuit

Fast acting fuses doesn't have

Notch

Time delay fuses have

Notch

The major causes of breakers is

Overheating due to the Loose connection on the load side

Over current

Overload current and short circuit current

Feed through GFCI provides

Protection to all outlets in that circuit

Non feed through GFCI only

Protects at the point of installation

Fuses AIC are

200,000A

A fault current exists when

An unintended path is established between an underground conductor and ground

Standard interrupting capacity has

Black handles and black interrupters

Time delay fuse must

Carry 5 times is continuous rating for at least 10s

Magnetic trip

Circuit cuts of immediately, short circuit, or nick in wire

H

High interrupting capacity

Time delay s-type fuse is mostly used

In motor circuits to compensate for high in rush currents

Interrupting capacity

Is based on test UL(underwriters laboratories) and CSA(Canadian standards association)

Downstream

Is closer to the load

Upstream

Is closer to the power source

FH

Is higher than H interrupting capacity(65,000A)

Mechanism means

Spring

AIC

The max amount the breaker or fuse can handle (amperage interrupting capacity)

Thermal trip

Wire Overheats which takes build up time