EBME Forums Forums Maintenance Technical Assistance PB 840 ventilator system

FYI
This is regarding the PB 840 ventilator system. We have a number of these in use and find them generally very reliable; however, two of our units have a history of intermittent crashing (totally locking up whilst in use)? The error log in our situation gave no apparent cause for this. However a few months ago it was accidently discovered that on both of these vents the external battery connector retaining screws had broken free (Even though the connection appeared secure)! After re-securing the battery connectors we have had no more problems whatsoever! In all “crash cases” the vent passed its subsequent EST including the battery test.

My reason for posting this? If anyone else has similar symptoms it may be a good place to start!

Regards

Eddie

That's an interesting post, Eddie ... from which two comments immediately come to mind:-

1) Remember the old PM mantra TLC? That is, never mind electrical safety testing, what about "tighten-lube-clean"? Surely those "loose" connections would (dare I say should?) have been picked up (rather than "accidentally" discovered)? Otherwise, why bother with PM at all?

2) Perhaps the world was a better, safer, place when ventilators didn't "crash" (see Cape-Waine et al).

By the way, in my experience, "locking up" fault conditions are invariably due to a "bad connection" somewhere. I mention this as I know that some techs just love to dive straight in to swapping out NAND gates and all the rest. Such excited activity rarely wins the day. Of course the real problem is tracking down which of the many candidates for "bad connection" is the actual culprit. Back to your own case, it seems that you were (or, should have been, lucky). One last point:- how did these faults occur, I wonder? I'm guessing that they may have been as a result of over-zealous application of the T in TLC ... am I right?

Hi Geoff, poor installation practice I guess? Maybe overtightening the retaining screws? As for the connection its a hybrid D-type connection and is not normally disturbed as its located behind the Gas hoses and connected directly to the BDU controller module!

Eddie

Hi Eddie
I note you state the error log gave no apparent clue but were there any error codes or events at all in the info / diagnostic logs? (related to the crash). It seems strange that such an urgent event doesn't appear to register any codes etc.
Thanks for the warning.
Topper

Hi Topper, that was my concern too?? The logs didn't contain anything that was related to this particular "lockup?" Normally the logs in this vent are very informative! I have emailed Nellcor for their opinion, will keep you posted!

Eddie

PS Geoff EST is an "Extended Self Test" in this case! not to be confused with "Electrical Safety Test" .... Easy mistake mate lol

Eddie

Damn ... I thought you were talking about Eastern Standard Time!

But (as Topper mentions), whatever sort of test it is, it's not a lot of use by the sound of it.

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