One of the most common mistakes I hear techs make is confusing zero ohms with infinite ohms. The fuse above is showing near-zero ohms, which indicates a good electrical path with very little resistance. If there is a perfect path, it would have zero ohms (which isn't actually possible unless you happen to be […]

Relays can be used for many different control applications, including controlling fans, blowers, other relays, or contactors, valves, dampers, pumps, and much more. A 90-340 is a very common, versatile relay that many techs have on their truck. So, we will use it as an example. A relay is just a remotely controlled switch that […]

In residential and light commercial HVAC, we work primarily with PSC (permanent split capacitor) motors. However, it is good to be aware of some other types. PSC (Permanent Split Capacitor) A common medium torque single phase motor with a run capacitor always in the circuit. This type makes up the majority of HVAC motors (condenser […]