Submersible pump

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Re: Submersible pump

Postby tertim » Sat Jul 30, 2016 7:02 am

Ians wrote:First up, forget everything that has been said so far.
If this pump is rated at 14 metres head and rated correctly, then it should deliver 14 metres whether it's in an open pit, well, sump, boat bilge or your birdbath or bathtub.

if it pumps when the water is at 3 metre but not at 5 then something is amiss. You need to know what the water level is in the well in relation to the intake of the pump, how deep is the well?

Test the pump by placing it in a 44 gallon drum or similar and switch it on, either restrict the discharge hose with a valve or crimp the hose somehow to apply artificial head to the pumps discharge and observe its output, even better if you have access to a pressure gauge, put it between the pump and the restriction in the hose.

3 immediate things come to mind, either the pump is running in reverse , which is impossible with a single phase unit unless it's wired internally incorrectly, or the impeller is loose on the shaft, or there is a major restriction in the pump casing or the outlet.

Pumps are very simple, usually trouble free but dumb beasts and applied incorrectly they don't work at all or not as well as they should.
Luckily it's a 375 watt unit and not a 2000 Kw cooling water recirculation or boiler feed pump - then you would have a real problem on your hands.


Hi Ians
I have tried what you suggested, put the pump into a barrel of water the 25mm outlet hose was taken up a scaffold and at about 5M head the water flow stopped altogether, when the discharge outlet pipe was at ground level (no head) there was a fairly good flow but was easily stopped by blocking it with my thumb, I would estimate the pressure at less than 0.5 Bar.
The reason I bought the pump was the claimed performance on the label and supposedly Japanese manufactured (proved a fake researched by MGV12)
I will return the pump to taiwatsadu for a refund!!!!

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Re: Submersible pump

Postby Ians » Sat Jul 30, 2016 7:21 am

Something very wrong, have you removed the strainer to look inside to see if any blockage.
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Re: Submersible pump

Postby tertim » Sat Jul 30, 2016 9:00 am

Ians wrote:Something very wrong, have you removed the strainer to look inside to see if any blockage.


Yes I've done all that, I think what's wrong is that they labeled it incorrectly should have been 14 FT head and not 14M also when the pump starts to run there is not much torque i suspect the motor is no way close to the 375W claimed.

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Re: Submersible pump

Postby Ians » Sat Jul 30, 2016 9:09 am

Very unlikely incorrectly tagged, could well be an electrical problem and the pump is not running up to its correct speed. Any way you can check speed, maybe your local motor bike repair shop could have a portable hand tachometer.
Otherwise return it, can you video it running in the tank where you tried it, to show that it doesn't pump.
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Re: Submersible pump

Postby MGV12 » Sat Jul 30, 2016 10:00 am

The 'fake' manufacturers can put whatever they like on a label as there is no independent testing by a recognised authority ... even if it says the pump is stated as having such. Some products don't perform from the word go, some do but have a poor life expectancy; some fail in both cases. I have used a Pedrollo Top1 pump in my pond for years ... Italian made and good quality, as most Italian pumps are. Someone I was visiting was complaining to me about a Top1 he had bought for his pond ... "pile of crap" he said. I asked him to pull the pump so I could look at it ... looked identical to mine ... just a blatant Chinese copy; the only visual difference being that they had put their own name in place of Pedrollo to avoid legal action. Pics of the two pumps:

top-1-pedrollo.jpg
Original Pedrollo
China Submersible Pump  TOP 1 TOP 2 .png
Chinese fake


Good idea to video it not performing but otherwise I wouldn't waste any more time on it .... pile of crap. How much was it by the way? Last time I was in TW they were heavily discounting a lot of pumps ... some [apparently] genuine ... some obviously fake. One thing they all had in common was that they were eco-unfriendly ... even if they did perform as claimed you could possibly pay out the discount 'saving' to your local electricity provider in a very short period. TW [and others who do the same] may be aware of the problem, or they may be oblivious ... catering for a [mostly] Thai market where people are used to such failings. I have never been let down when buying from smaller specialist shops where you can talk to the owner. As I mentioned previously [with some negotiation] they are not more expensive ... often cheaper.

“Some days I am an optimistic pessimist ... other days I am a pessimistic optimist”
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Re: Submersible pump

Postby tertim » Sat Jul 30, 2016 1:48 pm

You are correct MGV12 it's a piece of crap I paid about B1800 for it so not a huge loss put it down experience

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Re: Submersible pump

Postby Ians » Sun Jul 31, 2016 1:51 pm

I would like to take up the challenge that this pump is a piece of crap, sure it's Chinese manufactured and I for one probably wouldn't buy it as they are usually not of the quality I have come to expect after 40 + years in the pump industry, but without a good inspection of the unit I would reserve judgement and would be interesting to hear what the supplier says if and when you return it and they give it a good going over.

I recall one of our major posters here rubbishing a Grundfos pump that was brought and gave a few problems, now I would consider Grundfos the worlds top manufacturer of domestic and light duty industrial pump units -- but everyone can have an occasional dud unit.
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Re: Submersible pump

Postby MGV12 » Sun Jul 31, 2016 3:40 pm

Ians wrote:
I recall one of our major posters here rubbishing a Grundfos pump that was brought and gave a few problems, now I would consider Grundfos the worlds top manufacturer of domestic and light duty industrial pump units -- but everyone can have an occasional dud unit.


Update: Make that four dud units. I have also used and specified for customers Grundfos pumps extensively in the past .. however ... times change and none of us can be sure who are actually manufacturing products sold under recognised brand names these days. In a different market place ... Sony were for many years the go-to manufacturer for quality visual and audio equipment. They outsourced production to China and as a consequence their reputation dropped substantially ... they are still clawing their way back from that ... one major poster here has been vocal on the forum stating that he always bought Sony but would never buy their products again. Back on subject: Two Grundfos 30 CH-30PT pumps bought from Home Expert in Chiang Mai over a period of three months ....installed as per instructions; I also have considerable professional experience. Second unit failed within a few months of installation due to controller malfunction and bladder leaking. Although under warranty it was not easy to get HE to replace the pump ... fortunately [?] ... the second one failed in similar fashion shortly after installation. Eventually, after a visit from a "Grundfos rep" both units were replaced. One year on [and so out of warranty] one pump repeated the failure and not long after the other had bearing seal leaks. At this point I gave up and cannibalised the two pumps to make one. The fact that the original units were replaced under warranty I can only assume that they [possibly] weren't fake copies. Another major poster on here bought a lawnmower with a Briggs and Stratton motor ... as he knew this American manufacturers products were good. When it failed he was informed that he had a Chinese copy ... I also had a mower with the same engine and they looked identical; he hadn't checked the serial number: I had.

For a man with "40 + years in the pump industry" I am surprised that you appear to be defending a pump from an unknown Chinese source that is clearly not performing to its claims. There are a multitude of manufacturers in this segment and some of them are world class ... unfortunately the vast majority are simply making money on the backs of those who have spent a fortune in developing/manufacturing/marketing world class products. I occasionally buy pumps that have no warranty/no recognisable manufacturer/no verified performance data ... for non-critical functions .. and are well-cheap; some of which really impress. Otherwise I can't relate to anyone who would compromise their needs when the alternative not only fails to provide but also runs up their electricity bill unnecessarily.

Tertim: I realise that this thread may be more confusing than clarifying; hopefully it will lead you to a solution with local pump suppliers..

“Some days I am an optimistic pessimist ... other days I am a pessimistic optimist”
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Re: Submersible pump

Postby Ians » Sun Jul 31, 2016 4:02 pm

I'm not defending it, just commenting on that maybe it's not the pump at fault, as for unknown, seems this manufacturer is fairly well established and from what I see the products look reasonable (for Chinese manufacture). And after 40 years in the industry, I can count on 1 hand the number of pumps I have been directly involved with that proved faulty from the many number of "the pump doesn't work / its faulty/ something wrong with the pump" etc. on close inspection it's normally the application /installation / ignorance, not the pump.
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Re: Submersible pump

Postby MGV12 » Sun Jul 31, 2016 4:07 pm

Ians wrote: for unknown, seems this manufacturer is fairly well established


I only did a superficial search. Always happy to hear that Chinese manufacturers are good ... can you post links?

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Re: Submersible pump

Postby Ians » Sun Jul 31, 2016 4:12 pm

The operative word was reasonable :lol:
Will post website latter, too difficult using a smart phone as I'm not smart enough.
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Re: Submersible pump

Postby Ians » Sun Jul 31, 2016 8:27 pm

Just revisiting the photo's of the pump you supplied,
Question -- at the discharge port where the hose tail is screwed in - is that a crack in the casting and does it extend into the outlet port?
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Re: Submersible pump

Postby tertim » Tue Aug 02, 2016 1:06 pm

Ians wrote:Just revisiting the photo's of the pump you supplied,
Question -- at the discharge port where the hose tail is screwed in - is that a crack in the casting and does it extend into the outlet port?

Hi ians
No there's no cracks or damage to pump when I cleaned it up looks good. I appreciate your input and advice but I don't have much spare time to look any further into the pump I'm really quite busy building our house. At the moment I'm using the pump to flood the fill for the slab and it's doing a reasonable job albeit slowly, next year when I have more time I will investigate further.

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Re: Submersible pump

Postby Ians » Tue Aug 02, 2016 9:00 pm

tertim,

This is the area I was looking at - from here looks like a casting fault / crack
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