Problem Type: Facilities
Workspace: Metal Shop
Asset: Copco Compressor / Shop Compressed Air
Summary: No compressed air in the metal shop.
Additional Info:
Report generated from a filing. This report has also been sent to Asmbly staff, leadership, and space leads with any contact info that was provided. Provide additional photos or resources here to help. When the problem is resolved, ensure it is marked.
Was there a power outage there? Has anyone tried to turn the compressor back on (toggle the black switch)?
No power outage, where is the black switch to toggle?
I toggled the switch per the documentation with no effect.
i checked it a couple of days ago, oil level was fine at the time.
There is extensive troubleshooting guide on the wiki for that model.
Does it try to come on, then shut off?
if not, there is a protection switch inside that does not self reset but it does not trip without an underlying problem to identify and address.
it could be the main panel breaker is shut off, but that also needs to have an underlying cause identified.
in recent memory the 3 phase contactor did fail and was replaced. This caused one of the phases to fail to switch on and off with the others, and in a 3 phase motor that causes a high over current that pops the panel breaker and shuts everything down. A smaller point of use breaker is the recommended installation requirements but IIRC we haven’t put one in. In any case I would be surprised if the contactor is the issue since it’s recently replaced and typically a long life component.
I can come in later today to troubleshoot it if no easy fix comes up.
There was an oil leak from a high pressure fitting that wasn’t tightened down again after the last maintenance effort that has been spitting out bits of oil inside.
The immediate shutdown cause is the overtemp switch reading open, but FLIR showed it’s at normal operating temp. It’s also looking intermittent, more like a bad connection. The switch opening did seem to have a thermal component to it though- I got it to start from cold, run for a couple of minutes only to switch off at about 80 psi, switch and oil hose showed 85C on FLIR (normal oil operating temp is 70°C - 95°C, overtemp switch is >105C) and then it would refuse to restart until given like 10 min to cool down. Then ran up to the same ~80psi and 85C and stopped. There was a period in between where I held the main toggle at “start” and the contactor clicked on and off rapidly. I don’t think that should happen. Overtemp switch should be designed to snap open or closed and the likely failure mode is sticking one way or another. Actually the latching relay design could work with a PTC thermistor there and not a switch, but that would be weird.
There is a 3 pin Molex connector inside the compressor area and it was saturated with oil and it was pretty grimy overall. I hit it with a little brake cleaner to flush the oil out but there was some grime worked into the pins too. I tried to bend the Molex male split pins a bit wider to increase the surface contact force. Didn’t help. I tried replugging several times and wiggling it while holding the main toggle in the START position and it didn’t seem to get better. It did occur to me later that the 3 switch wires go into the sensor switch through a blob of something like epoxy and oil may have been able to creep down the interface and contaminate the switch contacts, ruining the switch. That’s what the blob seal is supposed to prevent but it isn’t normal to have it soaked with oil regardless.
Given that the switch is behaving a bit intermittently which seems odd (but I’m not sure how that switch works, it may fluctuate between on/off right near the trip point but usually they design something to pop into one position or another), and I watched on FLIR several times to see the oil thermostat open up and flow oil through the oil cooler normally, the oil cooler fins are clean, but then shuts down while at a normal operating temp, I jumped past the temp switch by disconnecting the sensor and jumping two pins of the molex together. Then it ran without any problem.
We did replace that switch recently (like a year or two ago) when it was shutting down for what was definitely real, legit overheating due to a bad thermostat. We might have gotten a bad (counterfeit?) switch and if we kept the old one- I think we did- then I’d like it try putting it back in since it wasn’t actually the problem at the time. It’s either that or the oil-soaked grimy Molex connector needs to be replaced. I’m thinking not the Molex though, I would expect that problem to get notably better or worse when wiggling the connector or trying to re-mate it but I didn’t see that.
So, looks like faulty overtemp switch, runs ok now with it bypassed. If we have the old one, we should try to put that back in, and order a replacement either way.
one small quirk- a panel wire on the led indicator pulled off and that causes some quirks where the led only lights when not running and same for the hr meter. i think I know where to put it but want to be sure.