Don't Forget To Turn Your Compressor Off!

[megadodo]

2 nights ago I was working in the garage, fixing a leak on the fuel level sender and stripping my petrol Flymo down as the speed regulator vane had decided to work itself loose! I started the compressor so I could blow away the dirt and grass from the mower before I removed the carb. When finished for the evening I forgot to tun the compressor off no biggie normally as when it kicks in the house lights flicker slightly which reminds me that I have left the bloody thing on.

Last night I remembered that I hadn't turned it off and wondered why I hadn't noticed the disco lighting! So popped out to the garage to be met with an acrid burning smell as soon as I opened the door.

A quick look at the compressor, after finally switching it off, revealed that the compressor part had stalled (very hard to turn it by hand, possible bearing failure) and had jammed the electric motor. This had got hot enough to melt the plastic components attached to the motor. I found the cooling fan and housing on the floor next to the compressor! I dread to think what could have happened instead of just a meltdown!

[maccavvy]

Phew...close call there fella.

[Shaft]

To be honest, I'd be more worried about why your

lights flicker due to the compressor kicking in?

[owlman2222]

quite surprised the RCD didnt trip (if 1 is fitted that is)

[megadodo]

Low mains voltage at the house and many many repairs to the overhead wires that feed the house! We have been promised a new supply but have yet to see it. Can be pain when welding as well as the "kick" required to start an arc can often be weak. (that's my excuse for poor welding anyway!

[megadodo]

I have been thinking about that as well, clearly the stalled motor didn't pull more amps than the trip, unless its faulty. I tested the trip and that works but that is only for earth leakage I guess! I may change the trip to be on the safe side. It's a 16 amp trip as the motor is a bit of a meaty beast. It was a recon motor from machine mart less than 2 years ago after the original decide to give up. I ought to complain to the friend who gave it me over 15 years ago. Things just don't last any more!

[Shaft]

I see, at least its a problem you're aware of then, albeit one that needs sorting.

 

[fry61]

If memory serves ---- once the slip angle of 14degrees has been exceeded on an induction motor it will stall & current remains same as max. load so fuses/RCD's will not trip; these are rated for inrush current at start. Most "home" compressors are protected only by fuse/RCD, these will work if their rating is same as full load current but nusance blowing/tripping will occur at times. Very few home installations use a proper motor starter which can tell difference between start load & overload. Hope memory for above is true.

 

If pump is still good check start-up relief valve is working( there will be air loss from it at start or air loss when shutting down.) To make the motors job easier, consider fitting a slightly smaller motor pulley; not so good at quick fill of tank but makes the motor draw a lot less current;which would be good if you have supply cable probs.

 

As an aid for failing memory add a small spotlight at comp plug-in socket --- so the light is on when-ever there is power to the compressor; works for me-- most of the time--- workshop all locked up & then wonder why a light is still burning.

[owlman2222]

if the plastic round the motor has melted, i would expect the inslauton round the motor windings and incoming cable would of allso melted, which is where the RCD would of come in, having not see it i was only under the impression it had.

 

bob ur memory isnt to bad at all

[megadodo]

The plastic shield over the starter cap has deformed and the mounts that hold the fan cover have melted and the fan itself has dropped of the shaft. It was still pulling current when I turned if off last night. I think Bob's explanation has satisfied me as to why the trip had't gone! Cheers Bob plus I like the "reminder" light, sweet & simple. I must see what my insurance cover is.

[richardm6994]

 

Back in 2003, firends of ours had a similar fault with thier compressor, however they wasn't as fortunate!

 

Basically their workshop which was home to their traction engine, merry-go-rounds etc....caught fire and burnt to the ground. To make matters worse, the 10 tonne of coal they had stored at the side of the workshop also caught fire.

 

The traction engine (named Renown) had water in it's boiler so the heat from the fire actually "steamed-up" the engine. Unfortunatley thought the engine was nearly completely destroyed.

 

When fire crews arrived, my mate asked them not to douse the traction engine in water for fear that the cold water would crack all of the cast iron components.

 

People from all over the country turned up to help restore the engine and just over 1 year later it was back on the rally fields fully restored (photo attached after the fire).

 

Lesson to be learnt......always switch things off!!!

[agent_zed]

my old boss for some reason always stored his compressor empty (is this normal? i certainly don't) so he'd leave the tap open. His wife accidentally turned on the compressor when doing something in the garage and then went back to the house. He came home to find smoke pouring from the garage as the oil from the compressor had all been used up as it was just sitting pumping away all day. If he'd left the tap shut it would have built up pressure and turned itself off.

 

lucky it didn't burn the garage down as the DB7, 2x grizzly quads and a KTM dirt bike were also in there!

[sj-bradley]

Lucky story. !

 

I have a mains feed from the house into the garage and I make sure that this is always off unless I'm in the garage. I also leave the light fitting switch on as this aids as a reminder.

 

(although I had to replace it recently when the last one started smoking for some reason.

 

I also like to purge most of the pressure out of the tank leaving around 2 bar inside to help prevent internal corrosion.

 

(How often do you remove the drain plug from the tank in order to let out any collected water?)

 

Once again, a lucky escape and a nice resurrection of the traction engine. Why didn't you call it the Phoenix? )

 

Simon.