Oil filled - compensated 8" electrical enclosure

Blue Robotics Vehicles BlueROV2
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The parts have arrived and it wont be long until the advanced electronic package will be installed in the 8" acrylic bottle. Together with the BR electronics there will be 2 of DC DC converters 600/24Volt, with combined capacity of 1200W.

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After initial tests the bottle will be filled with SHELL DIALA S4
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It then remain to see if all the electronics will take on the oil without any issues, and finally, withstand external pressure during testdive.

Have anyone tried using the BR components in oil before ?

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Nope… not tryed… any reason why you dont use tellus oil? what compensator do you use?..whats the plan for the tether?:wink: …eller på godt Bergensk…Ka e planen?:wink:

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Shell DIALA is dryer than Tellus and can take higher contamination before it looses it isolation. I believe you are referring to tellus 22 S2 or S3? DIALA is, according to info I receive from a large ROV company that are using both types of oil is that DIALA is gentler on the insulation on the cables. And rubber/plastic in general.
The compensator is self made and have a volume of 100ml.
Not sure I understand the question about the tether?

To answer you last question, whats the plan: The plan is, like I stated in my post, to install 2 off PDU`s in the ROV. The size of these are way to big for the 4" enclosure. Thats way I am going with the compensated approach. A 1atm bottle and encaps that size will be quite expensive in comparison.

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Yes referring to tellus 22 ;)…tether i was just wondering about what you will use;) ok :wink: Tnx

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The tether is a JM Robotics tether (not newest edition) reason for going up to 600VDC is the voltage drop seen on 400VDC. 600V 1200W is now only 2A and the voltage drop is significantly reduced. (50%) The 1200W is for light and thrusters + el.
Using 600 volt I can still mount a skid and supply 1500w through the same tether to tooling, Like HP waterjet, cutter etc.

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Looking forward to see your project :wink:

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Regular old Mineral Oil will do the trick. You don’t need something fancy. I have done dielectric testing on the material before up to 5000 VDC with a gap of about 3-4 millimeters and the resulting Insulation Resistance readings have been in the 100’s of GigOhms.

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You are not wrong off using the Diala. Its a nice oil for the purpose, most companies use Tellus 22/32, Mobilect, Diala, etc. for the electric enclosures.

Whats your expected internal temperature? Will you secure the lids in any way?

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Hi NjĂĄl
I havent been calculating or given the temperature to much consideration. I have no internal circulation of the oil either. I havent decided if Im gonna have the temp sensor inside the bottle instead of outside (really never had any use for the water temperature)

The lids will be secured stainless steel bands going from lid to lid.

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…did you use some kind of compensator in this?

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Christian
I have a passive compensator ie. not springloaded. The little overpressure in the system comes from the expansion of the compensator made from rubber.

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Can any one point me in the direction of both a passive and spring loaded compensators to buy?

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https://kystdesign.no/hydraulics/compensators/ …Hydraulic… but havent even asked for a quote :confused: …its expensive… but shuldnt be to difficult to build with the right tools?

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Maybe one of those little Firestone air springs? The bigger ones are used as hydraulic reservoirs in some commercial subsea applications.