Re: New Thread on A54 fridge pumps (ATTN: OLIVER Vela Nautica)


Porter McRoberts
 

All excellent points Scott.
Cold seawater is much better at cooling than warm seawater!!!

We actually installed an air-cooled compressor for the main deep freeze, so its not in the circuit.  That has helped with unsyncronized pump demand, but it does heat up the galley a bit.  

All are waiting for the brushless solution.

Thanks,

Porter/IBIS
A54-152


On Jul 10, 2020, at 4:03 PM, Scott SV Tengah <Scott.nguyen@...> wrote:

Porter - I run freshwater through the pump so scale/lime isn't really affecting me. Pump still dies prematurely.

The Frigoboat UK spec'd pump (4105-343 Flojet) is 24v and flows 3.3gpm. The Frigoboat compressors require 1gpm per the VECO documentation. Per my earlier post from Penguin UK, the concept is that a 24v pump running on 12v will be acceptable for continuous duty - that is not the case obviously.

Rudolf - Mohammad Shirloo, in the Med, has the same longevity as you. Apparently his pump has lasted over a decade. But two things help explain that:

1) Neither of you are full time.
2) Both of you are in the cooler Med.

Oliver said that after he changed the insulation on his galley freezer, his pump was running 15% (or thereabouts) duty cycle in Portugal. Now that he's in the tropics, it's up to 75% duty cycle. This mirrors my experience as my Flojet pump lasted far longer when I was in the Med. 

It appears the combination of higher ambient temperatures and higher water temperatures when he left the Med increased his pump usage by 5x. 

Curious - do you run the freezer? We often run two fridges and the freezer. With the three "unsynchronized" compressors, the pump runs nearly 24/7.

And with longer continuous running periods, the brush temp goes up a lot. And above a certain temp, brush wear appears to be exponentially higher. 

Based on this, we are trying to find a brushless solution.


On Fri, Jul 10, 2020 at 7:47 AM Rudolf Waldispuehl <Rudolf@...> wrote:

Hi Dean, 

You’re absolutely correct with the E51385 Interface. 

 

Yes, all ok on WASABI and hope you both are well doing too. BTW: we will winterize in Spain this year and postponed the Atlantic crossing to next season. 

Cheers 

Ruedi


Von: "main@AmelYachtOwners.groups.io" <main@AmelYachtOwners.groups.io> on behalf of Dean Gillies <stella@...>
Antworten an: "main@AmelYachtOwners.groups.io" <main@AmelYachtOwners.groups.io>
Datum: Freitag, 10. Juli 2020 um 15:09
An: "main@AmelYachtOwners.groups.io" <main@AmelYachtOwners.groups.io>
Betreff: Re: [AmelYachtOwners] New Thread on A54 fridge pumps (ATTN: OLIVER Vela Nautica)

Hi Ruedi,
Hope you and Sabine are well, and enjoying sailing once more.

I agree entirely with your description of the Danfoss-E51385 interface.

To make it maybe a little clearer, in our 24V boat the F pin is driven to +12V to enable the pump. Otherwise it floats (is disconnected) electrically. When it is driven to 12V, then the voltage between the + pin and the F pin is 24-12 = 12V. This is what triggers either the 51385 box or Bill's 12V relay. 

As you say, all of this is unrelated to the pump longevity problem. 

Best regards
Dean




-- 
Scott 
2007 A54 #69
SV Tengah
http://www.svtengah.com

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