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