Compressors - Is this right

RIN

RIN

Well-Known Member
Joined
2 Mar 2003
Messages
3,236
Location
West Midlands
Visit site
The compressor on our starboard KAD32 came on as soon as we started the engine. Trying to work out what was wrong we swapped over the relay inside the control unit with the one in the port engine - no change. Then swapped over the control module - no change. Then swapped over the microswitch (magnetic) that senses you have pushed the the throttle fully down and a result - it was now the port engine compressor that came straight on, with stbd compressor behaving normally Trots off to buy a replacement see here
STA43022.jpg

And was told £128 QUID - Politely declined to purchase microswitch

Question 1 Can this be true - it seems a ridiculous price

Then thought if I don't reconnect the switch, the compressor will just come on anyway at 1500 rpm so I probably don't need to spend the £128. So I left it off and restarted the port engine but the compressor came on straight away So now I am not sure anymore that it was the microswitch.

Question 2 I would have thought with the switch disconnected it should not have come on until 1500 revs is this right or have I missed something?
 
I had exactly the same thing.

And yes, it really is that price. Disconnecting it doesn't help: you need to pay Volvo lots of money to stop your compressor running continuously!
 
We've just had the same thing on our starboard
KAD32 - you need a new one and unfortunately,
it is that price. What a bargain! :-(
 
That looks like an industry standard microswitch to me, and I bet you could source one for (possibly a lot) less than a fiver. I would try Maplins, RS components etc for a start.

If you are uneasy about connecting up a new one yourself, why not take the old switch on the bit of loom in the photo into any small electrical repair shop and ask them to supply and fit a new switch for you? Chances are they will have an equivalent in their stock spares and it shouldn't take them more than 10 mins to fit it
 
likely the 'switch' will have manufacturer/model details stamped/moulded on it - get those & have a search or post here.

appears to be a std V3 mounting, a a Pepperl + Fuchs to judge by the photo, £25-30 +vat from http://uk.rs-online.com/web/search/...eveTfg&Ne=4294957561&N=4294918811+4294956166 if they stock that model...

<trivia> In 1943, the V3 switch was named to represent Victory in Europe, Victory in Asia, and a Victory for MICRO SWITCH products. The first class postage stamp at the time was an eagle with outspread wings in the form of a “V”. The cost was 3 cents. The V3 and postage size stamp of the switch all seemed to go together, so V3 it became. :)

http://sensing.honeywell.com/1/4/6/5/7/0/index1.shtml
 
Thanks Andy. Have been doing some work on this. It appears that Pepperl+Fuchs cannot supply the switch to anyone but the Evil Barstewards at Volvo. However, they do make a very similar switch, This one http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=2898506#header Which is looks as if it will do the trick, but does not have the connector at the end of the loom. I hope to have a go at replacing it this weekend.

One thing bothers me though, I thought the purpose of the switch was to switch on the compressor the moment you put the throttle hard down. If that is the case, why, now the switch has been completely removed does the compressor still come on the moment I start the engine?

IMPORTANT EDIT

IN fact this switch will not work with theVolvo engine, What is needed is a Pepperl+Fuchs NBB2-V3-E1-V1
 
Last edited:
Yes, you're certain to have to re-make the loom connections, that spec is for an "npn normally closed (break) sensor" - so a NBB2-V3-E1-V5 should do it you can find one, seems to be the same switch, but with terminals, not flying leads. P & F do show it as available, just a hassle finding a stockist if they won't sell direct, or have a huge minimum order value.

the 'break' function explains why you still have constant compressor - the control unit expects a closed circuit, which opens at full throttle travel - you've removed the sensor, so the circuit is open.
 
andyball said:
Yes, you're certain to have to re-make the loom connections, that spec is for an "npn normally closed (break) sensor" - so a NBB2-V3-E1-V5 should do it you can find one, seems to be the same switch, but with terminals, not flying leads. P & F do show it as available, just a hassle finding a stockist if they won't sell direct, or have a huge minimum order value.

the 'break' function explains why you still have constant compressor - the control unit expects a closed circuit, which opens at full throttle travel - you've removed the sensor, so the circuit is open.
Click to expand...
Hello,
I am not sure how successful such a late reply is, but does this mean if you connect the appropriate wires together (and which ones?), everything will work normally except at WOT? If so that would be certainly good enough to get you home.
Particularly interested because mine did the same just once some time ago, was cured by shutting down the engine and restarting, although WOT had not been used at any time. But when it has happened once.......
 
Last edited:
Hi

I know this is an old post but just to let you know about this switch, first of all it is not a microswitch, it is a proximity switch, no moving parts, I know because we spent ages taking one apart to find a copper coil and a very small electronic chip, not much chance of a repair here.

The problem being that although RS sell similar switches made by the company already mentioned in previous posts they do not sell the particular one you require. I cannot remember the particular spec/part number at the moment but I do have it at work.
 
There is no reason you could not just fit a normal micro switch is there? You just need to use the normally closed contacts and only two of the wires.
There may be a little bit of adjustment needed here or there but should be easy enough.
 
I can understand your thinking about using a microswitch but there is more to it than that. Hope fully there is a photo of the insides of it below, I cannot help but think if a simple microswitch could do the job would not they use one instead of this.

This is a quote from Pepperl & Fuchs, manufacture of the switch "The switch is part number 922FS2-B4N-V3-Z895 and is a inductive sensor which is made exclusively for Volvo. Unfortunately we are not able to supply it"

The volvo sensor is normally closed and opens when the sensor detects the throtttle lever. Now there is a switch NBBZ-V3-E1-V5 part no 67716, this has spade terminals on it so you have to cut off the Volvo lead and join it on the replacement switch as follows - brown to 1, black to 2 and blue to 3.

The last switches I bought cost around £30, a lot cheaper than the VP one.

I hope this is of some help.
 
They use the proximity switch as it has no moving parts and should be waterproof which inturn will make it more reliable.

If Volvo had used normal micro switches then the failure rate would be much higher.
It will still work fine for a few years though.

If it was me though I would just get the proper Volvo one as I hate to see things that are not quite right. Same as non genuine filters etc.
 
aquatom said:
If it was me though I would just get the proper Volvo one as I hate to see things that are not quite right. Same as non genuine filters etc.
Click to expand...

Aquatom - You should not encourage Volvo. Their prices for anything at all are completely outrageous. I can tell you that the part in question see OP inc vat is over £142. The part as shown by Peanuts is £30. They are having a laugh!
 
RIN i read your post with interest, but as said the correct switch is the right design for the job, no doubt chosen and borne out of months of testing way back when the kad42 was first born.

What you have to remmeber is the day you decide to sell and the buyer brings someone along like me who clearly notices your aftermarket mod. The buyer then knocks off the price of the switch and fitting before the deal id done, that money for the right switch is cheap compared to the rest of your engine.

By the way the reason your comp is holding in is the fact id say that the black box relay contact is melted together, or maybe the loom has frayed through giving the coil its earth as the wiring to the coil has its positive/live there all the time so any earthing on the loom will pull the coil in.

Or maybe you will have to dig even deeper if its the black box has failed.
 
I think the black box will be ok. The output from the black box is controled by a transistor so no moving parts there.

As a Volvo dealer I have to opt for the correct repair. If it was my boat it may be different!
 
volvopaul said:
By the way the reason your comp is holding in is the fact id say that the black box relay contact is melted together, or maybe the loom has frayed through giving the coil its earth as the wiring to the coil has its positive/live there all the time so any earthing on the loom will pull the coil in.

Or maybe you will have to dig even deeper if its the black box has failed.
Click to expand...

VP Thankfully it was the little green magnetic microswitchy thing that failed. It seems to be designed to leave the compressor on if it fails, my guess is that at least you can get on to the plane and not chug around at 6 or 7 knots.

I can also confirm the one that Peanuts made up (NBBZ-V3-E1-V5 part no 67716 from RS) does actually work

My KAD32s have (gulp) an aftermarket mod so I can switch the compressors off anyway. I hope that will not count against me when I sell the boat - The mod was made by a Volvo dealer though
 
You must log in or register to reply here.

Other threads that may be of interest

O
“The Dog that Didn’t Bark:” Yanmar. 4L HASTE.
Replies
2
Views
246
oldgit
O

Share this page

Top