Timeline for HVAC blows fuse when cooling kicks on
Current License: CC BY-SA 4.0
15 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 4, 2020 at 18:58 | answer | added | Zac | timeline score: 1 | |
| Jun 4, 2020 at 5:51 | comment | added | Ed Beal | Is this a heat pump both heat and ac ? A reversing valve ? Since you said the fan was working (fan on outside unit? Was my thought until I reread fan working if the outside fan is not starting bad bearings ? ) , I would use caution with only a 10 amp inline amp meter yes there is a fuse in the meter to protect it but I have learned the hard way on that where a 1 amp fuse that was blowing had enough draw to pop the fuse in my fluke, I only use clamp meters unless doing calibrations that I know will not exceed the meter rating. Is there a schematic for the system you could get a photo of? | |
| Jun 4, 2020 at 1:18 | comment | added | ThreePhaseEel | @Zac -- since it sounds like it's not a dead short, unlikely -- I'd make sure your meter's 10A range is fused, just in case, though | |
| Jun 4, 2020 at 1:12 | comment | added | Zac | @ThreePhaseEel Any chance of damaging anything doing that, since there will no longer be a fuse in there to blow? | |
| Jun 3, 2020 at 23:17 | comment | added | ThreePhaseEel | Can you plug the red lead into the 10A jack, put the meter on AC amps, stick the meter probes where the fuse on the control board normally goes, and then try turning the AC on? | |
| Jun 3, 2020 at 23:17 | comment | added | Zac | @EdBeal I don't see any flashing LEDs on the PCB. The compressor starts and the whole thing runs for probably 3-5 seconds before dying. | |
| Jun 3, 2020 at 23:16 | comment | added | Zac | @ThreePhaseEel Absolutely! | |
| Jun 3, 2020 at 23:04 | comment | added | Ed Beal | Do you have any flashing LED’s or a group of them on? The power failure and the fuse on the pcb is not A normal failure , is the compressor starting? A bad cap in the outside unit can make for hard starts and drop the supply voltage (if a inverter or vfd controlled this is a possibility) but I haven’t had a pcb fuse blow. The fan normally starts later when needed but could be controlled by the board not the contactor. But they are usually a bit larger. | |
| Jun 3, 2020 at 22:58 | comment | added | ThreePhaseEel | @Zac -- do you have a multimeter? | |
| Jun 3, 2020 at 22:58 | comment | added | ThreePhaseEel | @PhilFreedenberg -- since it's the control fuse, it's probably not the compressor. | |
| Jun 3, 2020 at 21:51 | comment | added | Zac | @JRaef Its the tiny fuse (3A) on the PCB for the air handler. | |
| Jun 3, 2020 at 21:42 | comment | added | Phil Freedenberg | Could be a bad compressor. | |
| Jun 3, 2020 at 21:25 | comment | added | JRaef | "blowing the fuse on the board"... Do you mean your Distribution Board in the house, or is this a fuse on a printed circuit board? If it's the Distribution Board fuse, what size fuse, what size wire and what it the nameplate amp rating of the HVAC unit? | |
| Jun 3, 2020 at 20:11 | review | First posts | |||
| Jun 3, 2020 at 23:15 | |||||
| Jun 3, 2020 at 20:04 | history | asked | Zac | CC BY-SA 4.0 |