Water Exposure of Pump

Your question pertains to the motor rather than to the pump itself. You should assess the severity of its environment along an increasing scale like this:

drips from above, no pressure
sprays from above and sides, light pressure
heavy sprays from any direction, with pressure
momentary submersion
prolonged submersion

NEMA (U.S. National Electrical Manufacturers' Association) and IEC (International Electrotechnical Commission) standards differ from each other, but each standard has levels of protection that roughly match this scheme. Following the standard used in your locale, you can check if the motor is suitable. In your example, a NEMA TEFC (totally enclosed fan cooled) motor would be typical; I think the IEC IP55 standard is approximately equivalent. (IP stands for "ingress protection"; my guess might be off by 1 in either digit.)

[Your language composition is just fine.]

Thanks for the answer. I ask this because this is happening in the factory I work. There are hoses from fire hydrants spraying above the pump to add cooling source for fin fan coolers. That's why it's like never-ending heavy rain that exposes a lot of pumps. Several pumps have water-contaminated lube oil. After we replaced the lube oil, several days later there were water again inside the bearing housing.

I'll check about the electric motor standard later, but currently the problem is in the pump. So, is there any standard about water exposure to centrifugal pump?

Why don't you just wrap up pump with a plastic bag? How do you know if water came from outside and not from pump itself?

Your use of english seems fine, just some details are lacking.

If I understand your issue correctly, I assume your pumps are horizontal split case type with bearings on both sides of impeller? And the pump and motor are mounted below some type of radiator or condensor unit which require a hose spray for adequate cooling?

If the answers to my assumptions is yes, then the bearings will be subject to problems from water contamination.

A simple roof over the pumps to prevent direct "rainfall" on the pump motor units seems the most logical approach, as several other commenters have suggested.

I wonder if putting an umbrella over it would make any difference.

rochford supply marine textiles has many outdoor water resilient material covers.

on-line.ds

It sounds like the pumps are moving fluids through some kind of cooler/radiator and you are spraying water in the radiator fins to increase cooling. The motors are getting secondary wetting due to this which is contaminating the bearing lube. I would be looking into the operation to see what can be done to add cooling to the system without having to resort to spraying water on everything.

There are thousands of pumps installed outdoors around the world in refineries and chemical plants operating just fine since they were specified as for outdoor installations. Like many said it is generally more critical for the motor to be specified as either TEFC, TENV, Weather Proof I or II depending on the severity of the environment.

It almost sounds like you have an indoor installation which has been made rather harsh by the use of a lot of water being sprayed around.

Most pump bearing housings are supplied with vents to prevent a vacuum from occurring within the housing or pressure building up. Outdoor installations have better quality vents to prevent moisture from getting into the housing. If your pumps were originally specified as an indoor installation you might not have the proper housing vents for your rain forest like installation. Also, if the bearing housing gets warm and you cool it off from the outside with a spray you might be creating a slight vacuum within the bearing housing and drawing in some of the spray and that might be the source of your oil contamination.

Yes Tornado, you are right the IP55 protection is for motors suitable for out door use. These motors are hose proof and can work in out door conditions. Motors are TEFC, having seals at end covers and terminal box, glands etc, and tested with pressurised hose. In order to have additional protection one can build canopy over the motor and pump.

http://en.wikipedia.org/wiki/IP_Code

I've always worked as a part of a multi-discipline team.
Over the years I must have changed 100's of pumps and motors. At a guess it would be a ratio of 3 motors to every pump. Water ingress is your enemy, I finally came up with a partial solution by sealing all terminal boxes with spray on plastic coating (the sort used to protect new shafts etc). In some instances I've used it on all associated electrical equipment in the surrounding area.

On our case we provide casing to cover the motor . That helped.

Pump is designed for outdoor conditions i.e. it should be able to withstand extreme weather conditions such as high temperature, humidity, etc. However there is a limitation for this. What type of pump it is.? Is it reciprocating or, rotary or centrifugal. ?If it is centrifugal is it single stage or multistage? Is it direct coupled or belt driven? Continuous exposure to water is not recommended unless otherwise it is a submersible pump which is designed for that. In some centrifugal pumps which is meant for high temperature applications ( Up to 150 C) it is usual for a pump to incorporate a jacket through which a small amount of cooling water passes to reduce the temperature in the stuffing box to below 100 C.

If I try to understand from your statement that pump is designed outdoor condition it means the pump could stand for the environment condition.

First we have to understand what the meaning of outdoor design, actually the pump itself is stand for whatever the water condition, the thing need to protect is just the motor itself, and this motor is protected with the seal in order to be able to face the water sprying conditon, or water dropping, and base on this the motors are clasified base on the sealing capability and it is identified as IP class for some standard, but this identifivaon is depend on what standard that use by that motors.

If we refer from the statement that your pump is designed outdoor it's mean that pump is stand for those effect of the environment, so if just rainy effect it has to be stand, ecept it there is human effect as sprying it will be depend on what the pump IP the IP of the motor will indicate you whter the motor is tand stand for the sparying water effect.

The other question why you have to spry the bearing, I think the bearing is provided with lubrication and cooling.

<...the bearing is provided with lubrication and cooling...>

Then connect it to a suitable coolant at a suitable flowrate, turn it on while the pump is running, and stop worrying about it.

The motor is wired through an appropriately-sized overload protection device set to the rated full-load-current of the motor, isn't it?

As A builder I have been responsible for the installation on thousands of residential irrigation pumps and also many potable water systems requiring wells and household pump and pressure systems. The equipment is designed to function in an out door environment. And it will usually function well for a given length of time. However providing a ventilated shelter that can protect from direct sun and rain will not only extend the life of the equipment, but will make it easier for disassembly when repairs are needed.

One doesn't have to park ones car in a garage, but the paint and interior vinyl will remain serviceable much longer if it is garage sheltered.

TMF

If you have to hose down the motor to keep it cool then it is under-powered and over-worked. You need a higher horsepower motor rated for "continuous" duty. A larger, "raintight", "continuous duty" motor will be designed to prevent water infiltration during a beating rain and draw less current, thus creating less heat.

Given your later response about finding the lube oil water contaminated after only a few days, I would highly recommend discontinuing the water cooling. Water contaminated lubrication is the #1 cause of bearing failure (according to the training I have had).

I'd also pay heed to TooMuchFun's response above. Placing your equipment in a more idea environmental condition will prolong the equipment life and reduce the whole life cycle cost (think about how much money is being spent replacing oil every couple days).

Nothing can happen to a pump, but electric motor driving pump must be waterproof also.

You might find a quick google of "water contamination bearing failure" quite enlightening!

pumps are designed for specific applications. The pump and impeler; motor and enclosure are designed for specific application. Check and see which of them sooths ur purpose. Dickson.