Waeco CK40 Hybrid D freezer/fridge

Oct 26, 2014
Dumfries and Galloway
2019 Pilote P650 GJ
since 2014
looking for some advice , I have the above chest freezer/fridge which has the ability to freeze items right down to -18c when on 240v ac .
The power requirements on AC is 65 watts so you would think an inverter with an output of 120 watts AC would power it up but on switching on the inverter which is just a Halfords supplied unit it makes a squeaking sound and at the same time a relay on the Waeco unit clicks on and off.
Would a pure sine wave inverter cure the problem


Free Member
Jul 25, 2007
Assuming a compressor fridge, the motor start up inrush current can be as much four - six times the running current.. so basically the inverter is probably too small for the start-up current, hence squealing .

Also the sine wave from a 'cheap' quasi sine inverter may be too square for the motor electronics. A larger PSW inverter is probably required, however,

to be certain I would contact Dometic technical for the correct size and type of inverter, as sizing too large would waste precious 12v power.. and money
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