fanshvacwiring
I replaced my old HVAC system and a friend suggested asking the HVAC company to leave the fan unit to use as a shop fan.
I thought it would be a simple task to add a plug to the motor and off it would go (or rather on…).
I've tried wiring black-black, white-white (there are multiple blacks & whites) with no luck. I appreciate your time!
Here are some relevant pictures.
Let's see if we can answer this in pictures. For one feed from the breaker panel, to have each of the outlets on their own GFCI, you want this:
For one feed from the breaker panel to have one GFCI protecting downstream outlets, you want this:
However, you say that you have a red and a black wire in the box, and this complicates things. You might have a MWBC (multi-wire branch circuit) feeding the outlets, with the red hot on one outlet and the black hot on the other:
Or, you could have something else in this outlet, in which case (espcially if you don't feel confident) you really need to contact an electrician to get it sorted out.
Absolutely do not leave the wires alone wrapped in electrical tape. Electrical tape does not have enough longevity to safely protect the exposed leads and can create a hazard in the future.
The blue wire exists to support the future addition of a light. The polite thing to do for your future self or future owner of your home would be to connect the blue and red wires. However, it is not necessary; if you do not want to, you can cap both leads with wire nuts.
Note that it is also legitimate to connect the black on the fan to the red from the ceiling, and the blue on the fan to the black from the ceiling. Assuming you have two switches, that will swap which switch controls the fan and which switch controls the light.
If the existing black-black connection doesn't work, you can try the black-red. If that does work, it would suggest that the switch for the fan has failed, although it could also indicate other wiring problems.
Best Answer
To me that looks like an ECM motor -- an "electronically commutated motor" or "brushless DC motor." This is a newer motor technology with a variety of benefits.. at the cost of being more complex. These motors can't run directly from a power source; they require a control system to operate. The good news is that yours appears to have that controller built into the motor.
Based on what I see in the wiring diagram I'd suggest keeping that PCB in the circuit too. It appears the PCB provides a convenient way of "programming" the controller's behavior -- things like how fast it should spin (implied the the choices of AC/HP size and AC/HP CFM adjust) and how soon it should come on and how long it should stay on (ON/OFF delay).
I've not had the pleasure (?) of working on one of these motors myself, but from what I can gather online (and considering there's no 230 V connection shown to your PCB), all those control signals are probably 24 V ac signals. It's possible you could have damaged the controller by connecting 120 V between pairs of black and white wires, but.. it's also possible the internal control was engineered to survive that kind of mistreatment. Though you probably could connect 24 V ac to some of the wires on plug 4 and get results, it seems much easier to keep and use the PCB.
Try feeding the motor and the transformer 230 V (or 240) on the black and yellow wires and put a jumper between the R and the G terminals. Be prepared to wait up to 30 seconds depending on how that ON/OFF delay setting works. If you get a response from the fan in these conditions you could experiment with the other programmable settings for CFM, delay, etc.