Weather Protection at Radars - Why and When use it?

[rhbbatista]

Weather Protection is not a cheap optional to radars, so I´m always wondering why / when using it (besides the critical cases). Should we use just when radar is outdoors exposed just to sun/rain?
Do you select Weather Protection when specifying a radar? When do you use Weather Protection and why?

[LorenR]

Hi Ricardo

What I have seen is that most of the customers provide the protection themselves when the instruments (in general) are going to be outdoors. But if unsure I would better include it, since the device requires to be protected from direct sunlight.  I would think that for radars, at least for compact mounted, considering they will be installed on top of the tanks (and maybe really tall ones), customer might not make the accommodations to protect it himself, as it wouldn't be as easy as covering a PT that is at eye level.

Indoors... mm... in general I have only seen devices with protective caps or even completely covered when having a harsh environment around them, say a pulp mill, or with chances of chemicals or dirties to fall over the transmitter's housing

[Jeff_Blair]

Pulling this from Ametek O'Brien website...they specialize in this type of stuff as a third party provider...

Weather protection:
"protects instrument electronic from radiant solar temperature gain as well as providing limited protection from blowing dust and rain"

It's the same on our radar.  You don't want the electronics to exceed their ambient temperature rating.  Generally, that's about 180 °F.

I honestly don't see the need for it very often.  The instruments have an IP rating and/or NEMA rating which allows them to be used in all types of weather...the additional weather protection seems redundant to me. 

I think it's used because it's in a spec and that spec hasn't been updated for years!

You can order it with the radar model code when getting a radar or you can also get it as a spare part:
https://download.schneider-electric.com/files?p_enDocType=Data+Bulletin&p_File_Name=pl_011-001_b.pdf...

[LorenR]

Citing LR01's handbook Pre-installation requirements section: "Protect the signal converter from direct sunlight. If necessary, install the weather protection accessory."

IP/NEMA rating protects against particles, enclosed hazards, and water.. but not solar radiation. 

I have seen instruments with sunshades almost everywhere: sugar mills, power plants, even at crude oil stations. And we had an issue once with a skid installed in a really hot weather, where the PTs triggered the alarms every noon, when the sun was at its most. I think this would lead to a different discussion: Why the sun has a negative effect on the instrumentation?

[LorenR]

Dear @rhbbatista 

What do you think? what have you decided at the end? 

If consider your question has been covered, please remember to mark the corresponding answer as the solution by clicking on "accept as a solution" in the specific response 🙂

[rhbbatista]

I´ve seen many instruments installed outdoors without any cover or sunshade, and working fine for years (mainly positioners). So the argument that weather protection is useful to protect from sun is not completly acceptable - maybe in some cases it make sense, but at othersI don´t think so.
I also agree with Jeff´s sentence: "I think it's used because it's in a spec and that spec hasn't been updated for years!". I´ve seen lots of this.
So I tend to believe that weater protection should not be selected just because the instrument is outdoors. But it´s necessary to undestand if at that client´s site normally instruments have protection from sun, indicating that the condition to exceed the instrument´s oprational specs are present and weather protection should be used.
I ´d encorage other that have read this to participate with their experiences, it would enrich the discussion!

[Jeff_Blair]

Let's see who else chimes in.  

Who else wears a hat on a hot sunny day?
I do.

I don't get a sunburn on my head and the shade keeps my face and neck cooler.

Same concept for a transmitter.  But, yes, adds to the cost.

[Jeff_Blair]

“It is a good idea to protect the transmitter from external heat sources such as direct sunlight as higher temperatures reduce the life cycle of all electronic components.”

[rhbbatista]

In fact it´s a good idea. But the weather protection will rise the price. Will the client pay the extra dollars (especially in comparison to a cheaper competitor who is not quoting)?

I look at the client specification. If it´s there, sure I´ll include. if it´s not I´ll present the functionality and let him decide.

By other hand the new LR5X, LR6X and LR7X has a plastic cover on top of the display that may works like a protection from direct sun light. Can we assume that? And just use weather protection on those just in case of severe weather conditions (what would it be?)?

[Jeff_Blair · Accepted solution]

I agree...match any RFQ, RFI bid exactly...if weather protection isn't asked for then don't quote it.

But, it may be suggested as an alternative in a follow up to a bid.

Yes, you can assume the plastic cover on top of the display (display screen cover) works as protection from direct sunlight.  But, it isn't a substitute if a customer or specification calls for "Weather Protection."