3000w needed to start a 1/2 HP 230v pump well?

[BIGISLANDHIKERS]

I was told by the company that makes my pump well that I only need 3000w to start and run the 1/2 submerged pump I have. I have been told by others that I need alot more. Trying to figure out what size generator to buy. Looking at a propane gen that is 120/240 with a 3500 watt max. It is the only one I have found in my price range at $500.

Thanks!
BIH

 

[velvetfoot]

I would suggest you measure it. If you don't have a multimeter that can measure inrush current, maybe someone you know has one. While you think the company would know, they're not the ones buying the generator!

 

[stee6043]

I'm not sure what hp my well pump is but I can tell you it takes my 5500W generator to the max when it kicks on. I don't think 3000W would be sufficient for to get my well pump going. But like Velvet said, you might want to measure it...

 

[velvetfoot]

My well pump is at 450'. No idea on the specs. My 5kw/6kw max generator wouldn't start it. I tried to measure the startup current with a clamp ammeter, but it didn't have the peak hold feature. I thought I saw 29 amps a couple of times. I wound up getting a 7.5kw/13kw max generator that did the trick. I just got a good deal on a clamp ammeter that does do the inrush, so it'll be interesting to see what it says. The pump can be made so it uses less current to start, but I think it takes a little extra cash.

 

[Highbeam]

I wouldn't expect the 3500 watt to do the job. You can get a lot more than 3500 watts for 500$. Go find a champion power equipment dealer. I use a Champion 3500 watt 120/240 genset and it only cost me 249$ a few years ago. I see them regularly for 299$.

A single horsepower is only 750 watts by definition. But that 1 HP pump will draw several times that power when it first kicks on. Unfortunately you will have to buy a big genset to handle the startup current and then the big genset will be lightly loaded the rest of the time. Big gensets suck lots of fuel.

 

[BIGISLANDHIKERS]

I wouldn't expect the 3500 watt to do the job. You can get a lot more than 3500 watts for 500$. Go find a champion power equipment dealer. I use a Champion 3500 watt 120/240 genset and it only cost me 249$ a few years ago. I see them regularly for 299$.

A single horsepower is only 750 watts by definition. But that 1 HP pump will draw several times that power when it first kicks on. Unfortunately you will have to buy a big genset to handle the startup current and then the big genset will be lightly loaded the rest of the time. Big gensets suck lots of fuel.

Seems harder to find in the propane model. Been looking at a champion 5000w for $659 but I have to pay $110 shipping as well so it knocks it out of my price range. I'll see if I can find a champion dealer in my area. Thanks

 

[velvetfoot]

Measure it so you know for sure first.

 

[BIGISLANDHIKERS]

I spoke to a tech at Franklin-elec and he says that the higher wattage is only for a split second and that 3000 would start it. Would a multimeter show the split second spike at start?

Thanks
BIH

 

[Jags]

I spoke to a tech at Franklin-elec and he says that the higher wattage is only for a split second and that 3000 would start it. Would a multimeter show the split second spike at start?

Thanks
BIH

Most "typical" multimeters will not read that high of amperage.

Take a look at your pump documentation. It should spec out the load requirements.

 

[btuser]

Starting motor loads are much higher (as every one says). I've got a 1hp well pump 400' down and it takes all of the 4500 watts to start the pump. I have to shut down other loads to cycle it. Your pump may have a capacitor that helps with the inital in-rush. It would be located at the bladder tank, but its not the pressure switch.

Edit: It could be in the pump housing but most I've seen are remote.

 

[Highbeam]

Even though the surge load is only for a brief time under normal conditions, that surge load will not end if your genset cannot satisfy it. The surge load will be the only load your puking generator ever sees.

 

[velvetfoot]

I'm totally no expert, but I've read that there are 2 and 3 wire setups and that the 3 wire setup are the ones that can have a controller (with capacitor) on the surface while the 2 wire has it down in the hole on the pump.

That new multimeter I got cheap with the peak hold feature goes for about 210 on Amazon:
http://www.amazon.com/Extech-EX830-...ref=sr_1_1?ie=UTF8&s=hi&qid=1296174204&sr=8-1
The documentation says it can measure current or voltage max or min peaks down to 1 millesecond in duration.
Somebody on another thread noted that it might be almost too quick, but I don't know...when I measured my pump it was about 11 amps steady state and 60 amps startup.

 

[BIGISLANDHIKERS]

I called the guy who installed the well and pump. He says 3,000watts should handle it but to make sure it was a generator and not an altenator. What did he mean by that??

 

[Highbeam]

That was a pretty weird thing to say. Maybe he doesn't understand modern generators.

 

[oldspark]

I called the guy who installed the well and pump. He says 3,000watts should handle it but to make sure it was a generator and not an altenator. What did he mean by that??

I'm not sure but I think it means he is an idiot.

 

[mikeyny]

BIG ISLE
you may just go ahead and get that 3000 watter and see what happens, but, I see that several folks here have experienced what you are about to, and have indicated the need for more power. Not to mention you may also need the fridgerator to keep the beer cold, that could be the straw that breaks the genny's back. think about it some more. Good luck. Then again most of us could live without the water if the beer was cold.
Mike

 

[BrotherBart]

Take a look at this bad boy. And shipping to your local store is free.

http://www.walmart.com/ip/ETQ-TG52T42-6000W-5250W-13HP-Generator/14146803

 

[amellefson]

Most breakers can hold the inrush current. That is why they are called "inverse-time" or "time delay." Power tools on 15 amp circuts are a great example. On the other hand I say get the biggest you can afford.

 

[velvetfoot]

If the generator just chokes it's a no go.

I started the water pump twice today on generator power.
It made a couple of deep gurgles each time but didn't choke.
I guess I'm good to go, but I wouldn't put anything else much on at the same time.