Reinstatement of Motors

Thank you for your time

Inspecting the gear box is to be recommended as well as the motors.

What is the enclosure standard class? Frame style?
NEMA Enclosure Standards of Electrical Motors - Engineering ToolBox
Insulation class?
NEMA Insulation Classes - Engineering ToolBox

Can somebody refurbish these motors for use, probably. Can five years of unsheltered tropical climate exposure to a motor destroy that motor beyond repair, possibly. Can the OP without outside help get these motors to work again, obviously this is not possible. The OP needs somebody on site familiar with similar if not these specific motors to assert the level of damage.

If I was in the OP's shoes, the first person I'd try to contact is the person that choose to expose these motors to the weather for the last five years. My next choice would be whoever I hired to maintain this equipment for their hands on evaluation. My third choice would be to contact the motor manufacturer with the motor model numbers to see if they would be willing to offer a free, no liability, opinion on the likelihood of these motors still being sound. My absolute last choice would be to ask an internet forum that cannot see the condition of these motors how to refurbish these motors. On second thought, this would not even be my last choice.

Depends on how close to the ocean you are...I imagine a quick inspection will yield more useful information....

There's always the bang test. Switch it on and see what happens.

I'm not going in to an exhaustive list of things to check. The site doesn't pay me enough.

As I said before the gearbox needs equal attention.

Overhaul the motors completely. Replace bad bearings, bushes, brushes if present, etc. Check if winding is not bitten or broken by rodents or anything else. Check rotor shaft for straightness. After these checks revarnish n dry stator n rotor. Grease dry bearings if sealed bearings are not used. Bearing housing must not be loose. This being done check terminals ,insulation, etc, repaint motors, switch on n there u go!!m

Invite professional motor repairers/rewinders & ask for an "Inspection report & quotation to recondition" the motor,gearbox,starter,pump etc

while the answer and suggestions to your problem have been good except for one, I can add nothing to those. However I would suggest that you look at the economic side of the exercise, which would be the less expensive option and maybe the quicker option, depending how soon you want to have these motors working.

As Tornado suggests, try and refurb them yourself, or get a motor company in to look and quote, at the same time look at the cost of new motors and delivery time of new motors and compare to refurb time & cost.

But you don't really know if you can repair these motors yet. So get yourself a fall back plan.... for buying new motors!

After refurbishment of the motor and bearings, do no load test run, measure the starting current and running current and compare with the vendor's data. Then only go for load test run.

If there would have been photograph of some of motors with your enquiry, it would have been easier and to the point advise from forum.

Since these are outdoor motors for a waste water treatment, I assume, these must be minimum IP55 or better class of degree of protection.

In case of IP55 or better, most probably motors shall be good (or as good as new) from inside.

Best option is to open one motor (since all are 200kW).

Check:

1. Condition of bearing seals. If damaged or deformed or in case of rubber lip seals check spring rusty and lost tension.

2. Terminal Blocks. May find sign of corrosion. can be revived by cleaning or replacement.

3. Stator winding: normally shall be fine for a sealed motor, if moisture has ingressed, you may find corrosion (blue Cu SO4 formed on inter-coil connections)or broken binding tape/cord of overhang portion. Rust on stator core etc. If corrosion is noticed - needs steam jet cleaning with detergent specific for motors and DM water., Drying, insulation resistance check and Flooding of winding and stator core with Varnish (Compatible with Temperature Class of motor - Class F or H) and curing of insulation.

4. Stator core: rust on core (pl see 3 above)

5. Rotate bearings and see if free. Could be bearings are double seals (type -2Z added with bearing number. If sealed bearing have not caught any rust - then these shall be find. Check quality of grease. Mostly you may find that over 5 years lying in one position, the oil has separated and drained down and what is left in bearing is hard soap base (like a hard grease). In this case replace bearings. On electric machines, mostly the bearings are of C3 clearance - hence note the bearing type carefully along with clearance C1 or C2 or C3.

6. Condition of insulation of leads between winding and terminals. Due to weather condition, it may develop cracks. sleeve it with woven glass sleeve to avoid any fault.

7. Make a list of spares (seals, bearings, power Terminals etc.)

Besides the location of seals on shaft will require polishing and external paint.

Where are you located and how many motors are to be serviced? In case you do not have enough trained manpower I am in similar business and can help you.

Regards,

Ramesh

In addition to all else said here, odds are that after 5 years of storage without rotation, the bearings are Brinelled (i.e. balls or rollers have deformed the bearing shells)plan on needing new bearings if all else checks out.

Once again, the seeming reluctance to contact the motor manufacturer directly and rely on a bunch of anonymous stangers in an internet Engineering forum is totally mystifying.

A simple telephone call will provoke oodles of advice and support, and save an unbelievable amount of time.

Any other approach is abstruse.

I wish to thank you all for your time in responding to my question.

I received some very good tips.

Alot of caution and pessimism being put forward here.

Assuming that the motors et al were fit for purpose and correct for the operating environment when initially commissioned and that they haven't been subjected to flooding or other abuse they're most likely OK.

Check if things rotate freely by hand and that all electrical connections are sound (including protective devices and starters) and if they are so then hit them with some juice. Probability of no problem is greater than there being one. If there is a problem then you'll know soon enough. What do you have to lose? Suck it and see.

I live and work in the tropics and encounter some installations that you "know" shouldn't work just by looking at them and yet they do.

The luxury of specialist advice at the end of a phone line is not available everywhere fellas.