5HP Motor Starter

Is it the right way to get 2 GA marks is to get rid of my question by transferring me to Google,i need direct clear answer sir.

I believer that Mr.redfred should give back your money.

If he brings me the receipt, I'll refund him double the amount I charged.

20 questions? Is that all? I think you are grossly underestimating the possibilities here.

I with you! If he has to ask for the kind of details his is asking, there is a real danger to him self and others. He may need the yellow pages under electricians instead! - JHF

Guest-

In order to get "i need direct clear answer sir." one must provide sufficient information within one's question. Google is often a good place to begin one's search for information, but definitely not the source of unquestionable perfect answers. For example, give me the numerical answer for "y" in the equation x² -y + r = 0. Impossible to find the numerical value for "y" since not enough information is given in the question. An answer can only be as good as the question! Lousy question results in lousy answer!

Also, don't forget that you get what you pay for.

Also, how can you judge the accuracy of answers obtained from a forum open to anybody? That answer could kill you if you think it is correct and it really isn't. (not referencing anyone who has submitted a reply to the original question).

If you want a better answer than what you are paying for, find a mechanical/electrical engineer with much experience in the installation/use/troubleshooting of pumps who you trust and pay him to solve your problem. Be prepared to either give him much more information or to pay him to obtain that information so he can accurately solve your problem.

Incidentally, I have that experience but I am now retired. That means I charge a lot of USA dollars and require a very large travel expense account. Don't bother contacting me.

Have gun; will travel.

$10,000 minimum.

Wire Paladin, San Francisco.

Fax 415-555-1212

You having an end of season sale?

You've dropped your price!

It was free of charge!

Quite likely. In India, there are usually two more situations requiring protection :

1. Dry run - no water, so no cooling. Electronic relays are available to stop the motor in such a situation.

2. Restart after momentary power outage - when power fails, the tall water column spins the pump shaft in the opposite direction. If power comes on now, the shaft can shear. This is prevented by a timer which prevents the motor being restarted until all the water has had time to drain away.

If the OP is in India, there are special pump controller manufacturers who include all these.

GA from me.

Normally, submersible pumps are fitted with a non return valve at their outlet.

To protect the submersible pump against dry running:

1) Use a Flow switch/Timer/Low Pressure Combination device which has a small pressure vessel incorporated. These are widely available nowadays. They have an electronic circuit with flow detection, a timer set at 15sec and a low pressure switching. Add the Overload and a phase failure if 3 phase motor.

2) If the flow switch combination device is not available or you cannot get a suitable sized one, then Install a pressure vessel + Pressure Switch + Flow switch (Honneywell...) in series on your pipe work coming out of the well. Add a timer set 10-15 sec in the panel. Wire the main switch + Phase failure Relay + Overload in series, then Flow switch N.O. & Pressure switch (Closing on pressure dropping below ~ 1 bar) & Timer (N.C. to open after delay) in parallel, then the control relay/motor contactor. The timer coil wired strait after the overload contact (above) and before the 3 parallel contacts.

3) Understand the circuit: P.Sw will open when pressure > 1bar (or minimum required pressure). T opens after 10-15s. F.Sw closes if water is flowing and remains as long as there is a flow. When flow stops, the F.Sw drops open and [C] releases, stopping the pump. The pressure in the vessel will initiate a flow next time there is a water demand....

It all depends on how you want to use the pump etc

Very interesting.Can you give a circuit incorporating a lockout contactor with reset button to prevent chattering of contactor/starter?.Such a problem was encountered in Saudi when contactor and timer were used instead of a PCB.

Also can use level electrode for dry run protection

Sir,

There are two protections you can use.

1) over current relay. to be installed on to your contactor.

2) One Single phasing prevention device by Minilec (An Indian co) They can give you a starter with all these facility)

3) In series You may put one more sensor for no flow condition for water on air vessel .

kiran nawathe

Normally a thermal overload relay will be sufficient for protecting motor from overload caused problems.

For submersible pumps it is absolutely essential to provide run dry protection (a simple form of float switch), as the fluid that is getting pumped flows through outside the winding casing to provide cooling to copper windings.

Basically the fluid level of a submersible pump cannot be allowed to drop below 2/3 of it's height (or even 3/4 by some manufacturers) Google FLYGT submersible pumps, their website is a minefield of information.

Cheers

When I worked in Agricultural engineering department 3 decades ago in India I faced similar type of problems. Some of of causes of failure of submersible pump are dry run,Over heating of motor,Improper connection of cable from motor-pump to control panel,Voltage fluctuations,mal functioning of starter and safety devices. You have to check one by by one and take remedial measures to avoid failures in future.

In India, here is a link to a comprehensive pump-motor protection relay, mainly targeted at the agricultural market. Conditions in the remote areas being : Low voltage, single phasing, occasional phase interchange by utility personnel when repairing lines which are down, frequent power outage, dry run, overload due to clogging....

Please check this out : minilec SPG D2

Usual disclaimer.

Good submersible pump controllers can be obtained from Franklin Electric. Check out the Pump-Tec Plus for single or three phase I am not sure of the motor manufacturer of your pump. The Franklin controls work on the Franklin motor. If you are using Chinese or Grundfos motors, the Franklin controls still may work but check first before purchasing. The Pump-tec retails at about $350.00.

The Pump-Tec controls many conditions; voltage fluctuations (generators), dry and auto restart, thermal overload, clogged pumps, etc. They even indicate why the pump was shut down for diagnostic evaluations.motors. They work very well (*) with minimal problems. We have installed such controls on landfill site application pumps and they have operated for >10 years. The pumps referred in the above are applicable to 4 inch submersible pumps for water.

Submersible sump pumps have a large variety of options including; float control, ultrasonic, proximity etc. Call your manufacturer for best recommendations for your situation.

For submersible pumps the following protections are required: 1)over current/over load 2)short circuit 3)winding temp alarm/trip 4)dry running protection(low water level) 5)no flow protection 6)Under voltage/Over voltage/phase reversal/single phasing/phase reversal- protection 7)Cooling media around motor stator(oil/water) You should also check cable size, voltage drop, contacts in starter, chattering etc If the rating of the pump is small it may not be economical to employ all the above. If you are not competent enough to trace the cause contact manufacturer or an engineer experienced in the relevant field