Repercussions of running a 220V pump at 110V?
 

I just acquired an MD-20RLT for dirt cheap, however it is 220V. I have it running right now at 110V (US). I am not an electrical engineer so what are the repercussions of doing this? Does the motor run at 1/2 power with 1/2 the voltage? Will this damage the pump? It seems to be running fine but kind of weak.

You shouldn't have any problems whatsoever, except for the observed lack of power.

Maybe you can look into replacing the motor. You might be able to substitute the motor with just about anything. The "Little Giant" pumps are similarly spec'ed, you might be lucky and be able to adapt it.

The biggest obstacle will be to find a motor that has the same size shaft. Then, you'll be challenged with mounting the motor perfectly straight to the housing.

Good luck!

I wouldn't be quite so confident. The motor *wants* to run at the same speed as this is dictated by the frequency of the voltage. However, as Ben noted it will not have the same torque potential due to the reduced voltage. The pump merely requires a specific torque based upon the flowrate and head. If you look at the speed/torque curve for a typical motor, the torque climbs as the speed drops. Since you have less torque at a given speed, this means your motor speed will drop compared to 220V operation. Motor efficiency also drops as you decrease speed. Your motor will run hotter for a given flow/head than it should. This may lead to premature failure of the motor.

Now, there's also the possibility that the motor was overkill for the pump and you may have no problems at all. Can't answer for certain without a lot more information, but at least wanted to make you aware of the possibilities.

There's the problem of 60Hz vs 50Hz as well. Pump rotors (..and stators) are calibrated to a certain frequency. Running em out of spec may further reduce efficiency and reliability.
If you swap the motor (ie the stator) make sure you change the rotor (ie the impeller axis) as well... Or else it may not run at all.

Good point about the frequency.

The coils will also allow a lot more current to go through, so you can most definitely expect it to run hot. You might want to check the amp draw, if you're equipped to measure it.

If I was you. I'd either try to sell it on EBay, and get a 120 Vac version, or swap the motor. Either way, you really can't run with it.

An alternative would be to get a transformer to step up your local voltage to 220. It's going to be bulky, but you'll have the added benefit of running 220V at 60 Hz, which will make your pump more powerful than spec. (see comparative chart of Little Giant pumps, 110 vs 220).

OK, I called Iwaki US, they said running the 220V at 110V is a no no. He said what you guys have said, it will run but the motor will get very hot (it did) and reliability is in the toilet this way too... Anyone in Europe need a MD-20RT?

I'm not sure, but if you state the price...

/edit/ sorry, I was in a hurry, guests...

I'd like to buy it, but it surely depends on price. Pls. let me know the price without the sh&h.

Thanx!

Aint quite so simple as shipping it to Europe, either. If it's got a 220 plug of the US style, then it's meant for 60 Hz. This should be on a nameplate somewhere on the pump. Yeah, it'll run at 50 Hz if meant for 60 Hz, and vice versa, but the efficiency thingie applies again. It should run only at the speed it was meant to run.

If it *is* 60 Hz then you are probably OK, but would need to do a little wiring. Pretty much all places are actually wired with 220 VAC, but other than electric dryers, water heaters, central air units, and stoves everything merely gets one 110 VAC leg. If you're near a 220 outlet or interested in wiring one on your own, it isn't hard. If you haven't done this sort of thing before, it's not something you want to try for the first time via "instructions I got on the web". Not particularly tough and I generally do it "live", but easy to get a shock you won't soon forget.

Let us know where you want to go from here.

Here's what you do. See those retardo plugs for the 220V crap in your house? Chop down the plug until you see what cord goes to what. Go down to Ace Hardware and buy a 220V plug, and solder and plug the bastard in. Alternately, do that mod to an extension cord to string from your laundry room to where your computer is at. As long as its properly insulated and you dont lose track of which wire goes to which prong on the plug, you'll be alright. If you aren't sure if you did it right, have your annoying neighbor plug the f*cker in and see if he lights on fire. If he does, be sure to have a bucket of water handy to put out the flames.

That's what my Weezil of d00m recommends, at any rate.

LOL, yeah, got the experience, twice. Last time burned dad's HDD (it was in my hand)...:D

Actually, I'm very familiar with electricity, screwdrivers, soldering iron and such. So, that's not a problem. ;)

If the pump is 50 Hz, I'm interested.

:p Yeah, but foam extinguisher may be better in case the safety thingie (dunno how you call it on english) didn't go off...:cool:

Yeah, still, interested only if pump is 50 Hz.

Thx guys!

I was talking to Nikhsub1, in order to use it in the US. As far as 50/60 Hz diffy's work, you should be fine running a 60Hz pump on 50Hz, though you will notice about a 10-20% degradation in overall pressure and flow. It shouldn't decrease the reliability of the unit, though. With that said, you never want to run a 50Hz pump on 60Hz or bad things happen.

And if it was your annoying neighbor, you really would want to use a bucket of water to put him out. It'll hurt more.

Mwahaha!

Ok, sorry for interrupt...:)

But, now you mentioned the neighbours...:evilaugh: tempting...tempting...

I took some photos of the pump, it says 50/60Hz, 220/240V You all know better than I! If you want to see the 4 pics they are here: http://www.netbetty.com/H20/iwaki/

http://www.netbetty.com/H20/iwaki/label.jpg

Do you have any idea how much it was used (if any)? And, subjective, state of the impeller and bearings?

Nik, plug it into your washer/dryer plug and be done with it. You might start to stink, but your pump will work ... just remember the part about your neighbors.

It looks to be used little, the guy I got it from said it was a "back up" whatever that means. It has a couple of scratches but it runs really well, I plugged it into a 220V outlet where I got it to test it. I have no clue about the impeller and bearings, I really dont want to take it apart...

NP,

well, I'm interested. It depends on the price. I cannot make you an offer, cos' I dunno how much to offer.
It's pretty late here in Europe, so you could post the start price, and wait till tomorrow this time, so more people can think about it, and maybe place a bid... Dunno...

Well I paid $50 for it so...

Think that 70 would be highest I'll go...

Pls, let me sleep over it, till tomorrow. Also, there may be more people interested...

Thanx!

OK, the picture helped a lot. All the 50/60 Hz means is that it'll run fine on either. Speed says 2000/2500 rpm for 50/60 Hz.

Pump head is proportional to rpm^2, so for a given flow rate you'd only have about 65% of the head available running on 50 Hz vs 60 Hz. Translation: For a given resistance (given WC system), your flow will drop to the tune of the 10-20% that airspirit noted above.

A transformer for use with that pump is not too hard to find.

The 100 Watt one shown here should do fine.

If you were willing to do some searching you could probably find something cheaper or free.

I'd happily trade a Danner Mag5 for it. :D

With a little wiring an isolation transformer like this could be used also.

Nik, if you decide to sell it, I can offer 75 $ plus sh&h.
I came back from the car mechanic, and that's what's left for the pump.

If you decide to sell it, pls. pm or mail me.

Thanx!