Relays and junction boxes.

[luckyjim37]

I have just been asked a couple of questions which I do not know the answers to so I thought I would throw them to the world at large and see what comes back.

Question 1, Do bog standard dc relays work in an oil filled box? I have never seen this done so I assume not but I do not know for sure. SMD put all of theres in the pod and from memory they were in one of the pods on an MRV as well.

Question 2, Does anyone have any recommends for a firm who can make small ROV junction boxes. The chap is based in the East of Ireland and so I suspect a company in the UK would be the way to go. It will only be going to a maximum of 300m.

Any thoughts would be much appreciated.

[rovnumpty]

LuckyJim

1. Think they should do, as long as the relay is vented to the ambient oil pressure. A solid state relay would be a better option though.

2. As it’s oil filled, you can use any water tight enclosure. I’ve seen plastic IP rated ones used in the past.

[luckyjim37]

Thanks,

I will pass that onto him.

[Ray Shields]

MRV5 had bog standard relays fitted in JB1 firstly for switching its quads and later for the zoom camera modification.

The electric pan and tilt box was an RS IP66 JB with a comp attached to it.

Both worked for manys a year down to 1500m.

[Sit Rep]

Elaborating on relays already mentioned by "numpty"; in the case of electromechanical relays, simply drill a hole through the outer plastic case, preferably at the uppermost point better yet drill an upper and lower hole thus preventing any air pockets forming.

[luckyjim37]

Thanks for the information guys. 10 Years in and still learning that,s why you have to love this work.

[slayer]

Also be aware some oils are better suited than others. To be sure, Use Diala or other di-electric oil. Have seen problems with Statoils HVXA because of additives leaving residue on contacts and in the end you won’t be able to switch the relay off.

[luckyjim37]

Yeah I have heard something similar. I assume he will use Mobilect 39 as that is available fairly readily in Ireland.

Same stuff as we use in our TMS sliprings.

[openside]

Thanks for the information guys. 10 Years in and still learning that,s why you have to love this work.

"Still learning" I beg to differ.

CLEAR TO SURFACE! 😆

[Author]

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