Compressor question

[shawndp]

So this morning our neighbour / landlord comes by and is like "did you do any electrical work" and we were like nope... he's on about how his compressor was spinning backwards and I almost thought fumes had got to him, but we went and looked at ours and it really was! The short version is that the local hydro crew are out and about with wires and they switched something around. The compressor now spins the direction of the arrows. Do I need to be worried about any damage? This may have been the case for the past 3 to 4 days... Thanks

 

[isb cornbinder]

Most compressor pumps work in both directions. If you have something more heavy industrial, with an oil pump, there may be some minor concerns about oiling.

 

[rsanter]

Standard compressor pumps don’t care about direction for pumping but they are directions for the fan pully wheel to move air properly

Bob

 

[Ilikeike]

I thought reversing a motor by switching leads could only be accomplished with 3 phase, do you have 3 phase in residential homes in Canada ?

 

[6768rogues]

I thought reversing a motor by switching leads could only be accomplished with 3 phase, do you have 3 phase in residential homes in Canada ?

I thought that, too. Switch any 2 legs (changes ABC into CBA) and it reverses the motor. What gives?

 

[LS6 Tommy]

Shawndp never said it was residential, but if it is, changing polarity on a single phase motor cannot change rotation. You would have to change the wiring on the motor itself. Sometimes a bad run cap will cause a motor to run backwards, but I've only seen it on split phase low torque motors like condenser fans...

Tommy

 

[yyc_ranger_4x4]

If this is really the case, then every motor in your residence would be spinning backwards....including your furnace (which has at least two motors), door openers, etc..

 

[shawndp]

I thought reversing a motor by switching leads could only be accomplished with 3 phase, do you have 3 phase in residential homes in Canada ?

This is at work and I do believe it is a 3 phase... sorry it took me a bit to reply - busy at work changing tires. The unit seems to be running ok a couple of days later so fingers crossed no long term damage. Thanks everyone!

 

[pancho400cid]

As said..... assuming we are talking 3 phase distribution where the phase sequence got screwed up by the POCO... that could be a huge problem depending on who all is being served by that system. Every motor on that system would be running backwards.... some motors have direction-sensitive blowers and will overheat if run backwards... usually on much bigger motors though... not likely on a small compressor. Also... compressors may (or may not) be ok running either direction, but lots of driven equipment (pumps, fans, etc.) will at least not work right, and may be damaged/destroyed.

Also as said, to reverse the rotation on a 3 phase motor, you can generally swap any two of the three phase lines... unless the POCO then comes back, fixes their mistake, and then you'd have to switch them back again....

 

[LS6 Tommy]

This is at work and I do believe it is a 3 phase... sorry it took me a bit to reply - busy at work changing tires. The unit seems to be running ok a couple of days later so fingers crossed no long term damage. Thanks everyone!

You need to check any circulating pumps or HVAC/R compressors and fans. Scroll Compressors, centrifugal pumps, all fans and blowers are direction sensitive.

Tommy

 

[Northislander]

This reminds me of a service call last year.
Got a call from maintenance manager at a facility we had done the install on, he had a three phase, ten HP deep well submersible pump only producing 1/3 of the gpm it "had been pumping fine up until yesterday" I asked if the lines were holding pressure and if anyone had been doing anything on the site in the last couple days. Yes lines hold pressure when pumps off so not a broken line. Electrician was working on site yesterday and had shut every thing down. I told him to make sure the electrician hadn't changed the wiring as if the pump is running backwards it will still produce pressure but but at a reduced flow. Saved me a three hour drive to troubleshoot the problem. The electrician had moved some breakers in the panel to make some room for another breaker.

 

[lakelandcat]

small thing but pulleys are designed to draw heat away from the cylinder heads,(thats one reason why they have a directional arrow) you may not have any problems but I would keep a eye on it.

 

[shawndp]

The utility people came within the hour of our Landlord giving them a call and there was plenty of apologies but no explanation. This is for sure a 3-phase set up. I don't remember seeing any external fans on the compressor and the rest of what looks like expensive electrical equipment is property of the landlord. The other consolation is that has been close to freezing, so I hope that helped with the heat.