Time and time again, low-voltage wiring gets the better of HVAC technicians everywhere. Sure, the wires are color-coded, but that doesn’t mean they’re easy to understand. On top of that, schematics sometimes look like ancient tablets written in hieroglyphics or something. But that’s where HVAC School comes in. There is a new 3D animation video […]

Connecting more than one wire on or under a single lug or connection point is called “double lugging,” and it is ONLY allowed in line voltage wiring under one condition, according to NEC 110.14: If the terminal, lug, or connector is specifically rated for more than one wire In the case of a conductor splice, […]

This topic came up because I was testing out the new MR45 digital recovery machine. That machine goes off by itself when it hits a 20″ Hg vacuum. It's a cool feature, but it is good to know when that level of vacuum is overkill and when it's not enough according to EPA requirements. You […]