We have a 480V oil pump immersed in 1

[thinker]

We have a 480V oil pump immersed into ATF (automatic transmission fluid). Pump vendor extended motor leads
using compression type butt splice with insulating sleeve
over the splice. Can we have any problems with that since
ATF would penetrate to conductors? May be there is a regulation which would require to use heat shrink tubing
on immersed wire splices? Please advise.

 

[dydt]

hi..
can they not use a liquid tight flex conduit and do the butt splice inside?..i am referring to the workmanship not taking the code in consideration yet..

dydt

 

[IRstuff]

Most compression connections are supposed to be gas tight, but there's usually little penalty if the connection is momentarily compromised, whereas here, any compromise of the gas tight connection will degrade the contact.

You should have a liquid-tight seal or solder or something that will not allow any liquid penetration. There was a posting a couple of months ago about a DC brushed motor submersed in some sort of oil and the problems it had with maintaining contact.

TTFN

 

[SteveKW]

A splice inside the conduit would be a code violation!

Ask the vender if he used an epoxy filled heat shrink. This would give an excellent seal at the splice.

 

[jbartos]

Suggestion: The proper way to extend the leads inside some liquid is by using a waterproof and submersible junction box with waterproof and submersible connectors sealing the cable or extending the conduit waterproof and submersible way.

 

[thinker]

Thank all of you for prompt response. Is there any regulatory requirement to have immersed connection sealed?
Something besides a common sense,and to prove the vendor
that he did a poor job which should be reworked in a proper
way.

 

[cbarn24050]

Hi, most oils are good insulators so it probably dosen't matter much.On the other hand if your just looking for an excuse not to pay the bill...

 

[dydt]

what concerns me is that vendor didn't even bother to put the wire in a conduit for mechanical protection... this should be enough to tell them to re- do their work..

if you want to get really mean...let them run new wire spliced right at pump motor termination box ( oil tight) then use oil resistant cable or liquid tight flex conduit going to the control station ( dry)...

dydt

 

[jbartos]

"Right on" Dydt.

 

[buzzp]

Splices are done all the time in submersible cable (water & oil wells). Splicing this type of cable requires care but if done right, will outlast the cable. We used three different types of tape (with armor on last-metal spiral wrap) with copper crimped and high temp soldered butt splices. The splices should be staggered to help prevent phase-phase shorts.
It is very easy to screw up the splice and get a blown cable. I have never dealt with tranny fluid in this manner so I would verify with the wire mfg that they approve of submersion in tranny fluid, especially if you suspect an unqualified "vendor". Good luck.

 

[jbartos]

Question to the previous posting: Please, how long does it take to implement such a very good splice and how much is the splice material or kit?

 

[buzzp]

I was supervisor over the cable guys so I always made them do it, hehe (much faster). It takes an experienced splicer about 15-25 minutes. It took me close to an hour (making sure I didn't screw it up and only have done 1 or 2 splices). I know the tape was rather spendy and I believe they were made by 3M. We didn't buy kits we just bought the materials; tape, lead, armor wrap(usually had this laying around). The lead wrapped around all three conductors after taping, etc. This was usually flat cable but we used the same method for round cable as well.

 

[busbar]

For fluid-immersed motors using either built-up or 'kit' cable splicing, routine installation expense by competents can typically be a small fraction of repeat rigging and repair effort, aside from production-loss considerations.

 

[buzzp]

Correct. If a splice blew out then the workover rig would be called back in at a rate (5 years ago) of $500/hr for every hour it sits there (working or not). Not to mention field service charges of $250 for an engineer and $200 for a cable truck and serviceman. Gets expensive real fast.