I just tested - you are right Jamie! The frigoboat interface outputs 24v (actually around 26.5 on my boat) to the pump!
 
I replaced the compressor a while back and had concerns because the Hella relay that came with the compressor was 12v. I mentioned this to Penguin and also asked about the pump because if you look up the part number for the Flojet 4105-343, it clearly states intermittent duty.

Below is the email I received from Penguin UK regarding the relay and pumps:

"Hi Scott,

 

The 12V relays are supplied as standard with the compressors. If the boat is 24V you need to use the pump interface – see wiring diagram attached.

Pump is also correct, we source them direct from the manufacturer in the UK which is why they have different branding, (it is a 24V pump that is run at 12V through the pump interface, which means it is then OK for continuous duty  (This is the only pump we supply for the Frigoboat systems)."

Engineers out there: I am not exactly sure where the 12v Hella relay fits into all of this, but my rudimentary understanding of wiring diagrams indicates that the compressors are getting 24v, so why am I using a 12v Hella relay??

The wiring diagram they reference is attached. Regarding the pump, it seems the common knowledge on the Amel forum (based on errant info from the manufacturer) is that the E51385 Pump Interface divides our 24v house system to 12v for the pump output. This is necessary, if what Penguin says about using 24v pumps on 12v is true. It seems we've all been wrong about this all along and the pump is getting 24v, hence is possibly why its dying so quickly.

Thoughts?

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