istherm voltage reducer

[owen-cox]

thanks all. Mine is like yours vyv. I am running it at 12v but it wont work wired to the thermostat so I am turning it on and off manually. Mine has 2 compressors (big freezer) so I think the issue is the three things cant get enough start up power with the pump at 12v. I will get the e bay converter recommended. I just don't understand why the isotherm unit is > £200 when you can get something that does the job for $20??? I know marine proprietry bits are expensive but 10*???

anyway, I'll order the bit and see how we go - thanks again all

When you say wired to the thermostat do you mean to one of the Danfoss compressor control boxes? as this is where it should be connected. if the pump is too powerful for the control box installing the LED indicator as per the manual will give you a fault code from the danfoss control box ( ir of you have the isotherm control with LEDS on it this will also indicate the fault) If the pump draws too much current you can install a 12v relay to start the pump directly from the battery supply and switch the relay from the fan output on the Danfoss compressor control box. it may be that the pump is tight and drawing too much current and that is why the voltage dropper failed?

 

[vyv_cox]

When Owen built my unit for me it used a four port secondhand Shurflo pump, very large for the purpose. I decided to replace it with the Par Max1 shown above to save power, as the fridge runs continuously all summer. However, in the meantime I had installed a voltmeter/ammeter and found that the current draw of both pumps was very similar and very small, less than 0.5A. A domestic water system pump draws around 3A thanks to the pressure generated but these open-ended fridge systems are miserly by comparison.