gulper pump failed

[DBA Forum (B) - David Beaumont]

I've just dismantled our Gulper pump which must be about 15 years old as it finally stopped working after quite a few intermittent failures. It looks almost as good as new, all that has failed is a 6 amp diode (P600D) inline in the positive supply, immediately after the terminal connection. I've ordered another they are cheap but I am wondering what it was there for. I can't see any point to it except to protect against an installer wiring it up the wrong way round. I'm tempted to just bypass it. Can anyone think of any other purpose for it?

David

[DBA Forum (B) - Chris Williamson]

To provide a Voltage drop? Nah!






Chris
D. B. Orca




-------- Original message --------
Forum (B) - David Beaumont'
Date:19/08/2014 9:22 PM (GMT+00:00)
subscribers
pump failed






I've just dismantled our Gulper pump which must be about 15 years old as it finally stopped working after quite a few intermittent failures. It looks almost as good as new, all that has failed is a 6 amp diode (P600D) inline in the positive supply, immediately after the terminal connection. I've ordered another they are cheap but I am wondering what it was there for. I can't see any point to it except to protect against an installer wiring it up the wrong way round. I'm tempted to just bypass it. Can anyone think of any other purpose for it?



David

[DBA Forum (B) - Chris Green]

Post by DBA Forum (B) - David Beaumont
I've just dismantled our Gulper pump which must be about 15 years old as
it finally stopped working after quite a few intermittent failures. It
looks almost as good as new, all that has failed is a 6 amp diode (P600D)
inline in the positive supply, immediately after the terminal connection.
I've ordered another they are cheap but I am wondering what it was there
for. I can't see any point to it except to protect against an installer
wiring it up the wrong way round. I'm tempted to just bypass it. Can anyone
think of any other purpose for it?

Reverse polarity protection is all I can think of too, maybe it
reduces the spikes sent back up the wiring?

It seems odd that it went intermittent, diodes don't usually fail like
that.

[DBA Forum (B) - David Beaumont]

There is a capacitor wired up between the + and - supply immediately after the diode. In fact those are the only two electronic components in the whole pump. I would have expected either direct wiring to the pump or a circuit board with several components. I assume the capacitor is to give a gentle start and stop to the motor. The diode stops the capacitor draining to the + when the + is switched off. I don't really see much point in that, I suppose it stops the + lead being live for a time after the switch is off, if the motor doesn't drain it. The pump seems to work fine without the diode but I assume it is related to the capacitor so will replace it.

David

[DBA Forum (B) - Daniel Boekel]

On Wed, Aug 20, 2014 at 4:58 PM, DBA Forum (B) - David Beaumont <dbabarges-pvYRptiajiAdnm+***@public.gmane.org> wrote:



There is a capacitor wired up between the + and - supply immediately after the diode. In fact those are the only two electronic components  in the whole pump.
Ah then it is a polarity reversal prevent device, as the capacitor can blow when subjected to reverse polarity.