LV Motors require space heater at Peru, South America? 1

[lakshmanan1974]

Folks,

I am currently preparing datasheet for LV Motors for our ongoing south american country Peru. The type of project is oil and gas project. The site conditions are as follows:

Site extreme dry bulb temperature: 29 dec.C (max) and 11 dec.C (min)

Relative humity, %: 95 % (max) and 60 % (min)
Site environment : Damp and Saliferous
Average annual rainfall, mm : 18

Under the above conditions, it is required to provide space heaters for the LV Motors. Can any advice me, Advice from Manufacturer side engineers are most welcome.

 

[Mstrvb19]

I am not 100% sure I am clear, but I think you are asking if space heaters are required? Space heaters are more important for keeping equipment dry than they are for temperature. With such high humidity, if these motors are outside I would recommend it. However, I am not a manufacturer. If my re-phrase of the question is correct, perhaps a manufacturer will respond.

 

[jraef]

Typically the criteria is if your motors are ever exposed to temperatures below the dew point, which varies with RH.

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

JRaef.com
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[waross]

If the dew point in the morning may rise above the night time
dry bulb temperature, you can expect condensation in large motors and generators. The thermal mass of the motor or generator may not increase in temperature fast enough to stay above the dew point in the morning, as the ambient temperature rises.
I don't often worry about condensation issues with indoor motors in Canada, but I am concerned with preventing condensation with all large motors and generators both indoors and outdoors in Central America.
respectfully

 

[itsmoked]

If you are specing the motors to buy, I would add the "heater option" in that humidity.

That is a lot of humidity for a measly 18mm of rain!!

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[electricpete]

Add my vote for space heaters.


I had to look up saliferous. Apparently it means salty. I'll have to try that out on my wife at dinnertime. "Honey, this food is too saliferous!"

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[rmw]

Mine too, and design your logic so that when the motor breaker is open the heaters are energized. Don't depend on operators to do it.

rmw

 

[waross]

Hello Mstrvb19;

With such high humidity, if these motors are outside I would recommend it.

Good advice. To take it a step further, in the tropics heating is rare. In an area with any amount of machinery it is common to see windows with no glass and doors similar to barred cell doors. Indoor ambient conditions in machine rooms are often the same as outdoor ambient conditions.
I spec a lot of residential back-up generators. Anti-condensation heaters are one of my standard specs.

It is also a good idea to energise the heaters of large spare motors in storage.
respectfully

 

[taxidi]

Hi,

I have a strong experience of power plants motors an generators in Islands and ships, the best result I had on keeping moisture out of winding, low or high voltage was using a combination of: Space heaters in bottom of generator casing and strip heaters directly attached to outer part of the winding extensions, this is one standard an inexpensive solution.

I have protected production generators on sea shore location often affected by hurricanes, with a 100% protection for 10 year periods. How is it done?

(Easy done in the case of a new order, just require it from the factory, some will do it for you, or you can have a shop do it before shipping out) Disassemble the machine bake it if possible just before, not to imprison humidity under. The product to use is a " Dow corning " liquid silicon (Color gray)it comes on 5 GL pails,(Any EIS representative will find the product for you) liquefy it even more with Xylen and spray it with a spurge gun on the entire stator winding (Not the rotor). Especially right where the coils exit the slots, on the slots wedges and along the coils in the slot aerators. On large motors or generator the air gape is plenty big enough not to worry about the rotor touching (Of course don't over do it).

This method will give a nice silicone gray finish, the winding will be completely isolated from the ambient environment, and it also gives a mechanical resistance to foreign particle like sand or other corrosive materials.

I have generator units by the sea, that I did 10 years ago that still hold in the G/Ohms with a 5 Polarization Index.

This will solve the humidity problem.

 

[motorman]

This high humidity environment most certainly requires space heaters. Also, per NEMA 20.29.3, salt-laden air and damp locations are considered as “Unusual Service Conditions”. Meaning that by not specifying space heaters for this area [AND using them!] could be considered has faux pas on the purchaser’s part and gives the motor manufacture a way out of a warranty responsibility.

More needs to be considered other then just space heaters. What kind of enclosures are you specifying? TEFC or just weather protected?