Hi,
I just noted that Burlen is now selling all dual polarity fuel pumps.
This makes it almost certain that the new CZX1004 suppressor is not
polarity sensitive. Seems like they should have done this a long time ago.
Regards,
Dave Russell
Simon Lachlan wrote:
> Hi,
> This is just what I need. I'll order up the bit from Burlen and tackle the
> job with confidence.
> Thanks a lot,
> Simon.
>
> -----Original Message-----
> From: Dave & M [mailto:rusd@velocitus.net]
> Sent: 04 October 2006 23:14
> To: Simon Lachlan
> Cc: healeys@autox.team.net; 'Bob Spidell'
> Subject: Re: positive negative fuel pump.
>
> Hi Simon,
>
> This may be difficult but I will try. Draw this out as you read:
> Looking down on the top of the pump, insulated cover removed, Orient the
> pump so that the movable contacts are at 12:00.
>
> Moving clockwise to 3:00, there is a mounting screw.
> Next at 4:00 is the power input stud, call it terminal 1.
> At 6:00 is the moving contact anchor & pump coil wire connection, call
> it terminal 2.
> At 9:00 is another mounting screw with a copper braid attached. This is
> the internal ground terminal - case ground, call it terminal 3.
>
> A condenser would normally be wired between terminals 2 and 3. Across
> the contacts.
>
> A diode would be connected to different terminals. ie. 1 and 2. Across
> the coil.
>
> The diode wired for positive ground would have it's cathode on terminal
> 2 & it's anode on terminal 1. For negative ground, cathode on terminal
> 1, & anode on terminal 2.
>
> I have no idea what the CZX 1004 device actually is. It could be a Metal
> Oxide Varistor (MOV), or a condenser, or a diode. The MOV & the
> condenser are not polarity sensitive, the diode is.
>
> To identify a diode's polarity, using an analog ohmmeter set on a low
> scale, it should read low ohms with the meter's positive lead, usually
> red, connected to the anode & the meters negative lead, usually black,
> connected to the cathode. With the meter leads reversed it should read
> high ohms. Since not all ohmmeters are color coded this way, it would be
> best to apply the ohmmeter to a separate DC voltmeter to verify polarity.
>
> If the device reads high ohms in both directions, it is either a
> condenser or a MOV & is not polarity sensitive, or it is defective.
>
> One possible clue is that the CZX 1004 has a ring lug on one lead & a
> spade lug on the other lead. I'm guessing that for positive ground the
> spade lug would go on terminal 2 & the ring lug on terminal 1. VS for
> negative ground. This is just a guess so best to verify with a meter or
> contact Burlen.
>
> The internal pump leads do not need to be changed.
>
> A picture would be worth a lot of words right now.
>
> Regards,
> Dave Russell
>
>
>
> Simon Lachlan wrote:
> > Bob, Dave,
> >
> > Thank you for your for your time and trouble.
> >
> > It seems like the Burlen part, hopefully below, is the best way to
> > go.
> >
> > http://www.burlen.co.uk/partDetail.aspx?pump=&partID=51169
> > <http://www.burlen.co.uk/partDetail.aspx?pump=&partID=51169>
> >
> > And the price isn?t bad.
> >
> > Is there a polarity to the item? So that it can only safely be
> > connected one way..? Can one tell by the shape of the connectors? Or
> > by ?
> >
> > Would I need to switch the leads to the pump around?
> >
> > Thanks,
> >
> > Simon
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