Turned on MCP600 without water for 3 seconds...

[shyet]

So I set everything up, short my PSU, but I forgot to switch off the power supply. So when I plugged in my power supply, everything turned on including the pump and there wasn't any water in there. Did I just permanently damage my pump? It seems to be working fine but I wanna know if I'll encounter any problems in the future. If I did damage my pump, would there be something I could replace.

I feel like a complete dumbass. F*ckin 80 dollar pump and I just f*cked it up.

[|kbn|]

It should be ok if it still works... Ive heard it damages the pump to run them dry, unless there ones designed for it. How long did you let it run for? Ive ran my ehiem for about 10 seconds no water before I relised it doesnt suck up the water when dry (when I first got it)

[shyet]

It ran for about 3 seconds without water, 5 seconds max. The instructions says not to run dry even for a quick test, immediate and permanent damage will occur. now I'm scared.

[dogbait]

We're talking about a few thousand rpms per minute for a pump like that without water against a dry bearing, which at that speed is going to heat up and deform the spindle and bearing pretty quickly. In 3 seconds I doubt much damage would have occurred, especially if the bearing is ceramic, but you'd have to wait for Bill to give you his opinion (backed up by fact no less!) for a definitive answer.

All I know is that my Iwaki hasn't been any less for the few occasions I've turned it on dry by mistake, nor has my aquarium pump which has been running with lousy plastic bearings for five years now.

[BillA]

should be ok (but try to remember, eh)
we don't test them that way dogbait, no time to failure for a dry pump

[jaydee]

I ran my Little Giant 170gph pump dry for a week my mistake. Ran fine for another year. Wouldn't make a habbit of it though.

[shyet]

Thanks I was worried but not anymore. Let's say someone runs the MCP600 dry for 30 seconds to a minute, what would happen? Permanently screwed? Or would there be some parts that you could replace? For example there was a leak in the system and all the water went out.

[Varsis]

Originally Posted by shyet

Thanks I was worried but not anymore. Let's say someone runs the MCP600 dry for 30 seconds to a minute, what would happen? Permanently screwed? Or would there be some parts that you could replace? For example there was a leak in the system and all the water went out.

I'm sure if we sweet talked bill he'd find us the parts to fix em.
but dont make a habit of it eh!
ran my hydor for 5 minutes dry by accident once going on 3 years with out problems

[Jabo]

dogbait described it pretty well
Mind you these are high quality parts used there so it takes some punishment to brake it.
You gonna be fine

[BillA]

replacement head $20 + shipping, from Swiftech

[Gooserider]

Don't know if it is totally relevant, but I used to work in a photo lab, where we used alot of large mag drive pumps on the equipment, mostly because of the chemical issues. These were similar in construction to an Iwaki, where you had a magnetic cup attached to the motor spinning around the outside of a nylon housing, with a magnetically coupled rotor on a ceramic shaft inside the housing. We had several times when fluid flow to a pump was shut off for one reason or another, leading to pump failure.

My experience with those pumps at least was that the motor generally didn't get hurt. The failure process was that the rotor would heat up on the ceramic shaft until it seized onto the shaft, the shaft would then start spinning until it got hot enough to melt the nylon housing inside the drive cup. The nylon would sag onto the cup and get smeared all over it. By this time there was enough noise and stink to attract attention, or someone would notice that the fluid wasn't circulating....

As I said, the motor usually was OK, but the housing, rotor and shaft were trash. The cup was also considered trash until I started chucking them in a lathe and going in with a cutter to clean out the melted nylon. (At a replacement cost of $30 ea. vs. 20 minutes work to clean one up, this made me real popular with the boss...)

So if I inadvertently ran a pump dry, I'd reccomend dismantling the drive head and looking for melt damage. If none is found, then you may have lucked out.

Gooserider

[shyet]

Thanks for all the replies. So far everything seems OK. I'll dismantle it to look for any metling/warpage if I encounter any problems in the future like noises, vibration, etc.

Thanks again.

[BillA]

Gooserider
fairly good description

I would add that an incremental bearing failure (such as we had to deal with initially) can add sufficient resistance to de-couple the drive magnet, w/o any melting apparent

one of the advantages of the MCP600 is that the pump head can be replaced with 4 screws
$20 + shipping

of course a Rio can be bought for the same amount . . . . .

[Gooserider]

Bill;
Thanks for the kind words. I guess that the incremental failure detection method would be checking for flow volume / pressure, but that isn't all that easy for a user that doesn't have a good collection of test gear. My "look for meltage" check might not catch the marginal failure, but certainly if one sees meltage you KNOW there's a problem.

Purely speculating, but if the decoupling failure effects both volume and pressure then I suspect the easiest test would be to do the quick home made manometer setup and see if the pump could still push the rated head.

Gooserider

[BillA]

nooo, much more simple than that

when the drive magnet decouples the pump stops pumping - period
if the motor is stopped, then re-started, the pump will often pump again; until it decouples

if the pump is not pumping, but still running, its the pump head

[Gooserider]

Ahh.... Glad to hear its that simple and clear cut. The way you were describing a decoupling failure I thought you were talking about a partial failure where the cup was still driving but with alot of 'slippage'. IOW, so that you'd still be pumping but with less pressure and volume than you should be getting. That might be hard to detect.

If decoupling means no pump action at all, then detection would be far easier.

Gooserider