General > General Technical Chat
Modified Sinewave Inverter Efficiency and Refrigerators
(1/2) > >>
jonovid:
efficiency of the inverter generally ranges from 95 to 98% as stated by some? but is this true of most cheaper modified sinewave inverters?
if I have a 300 watt AC refrigerator,  is a modified sinewave inverter rated at a continuous 600 watt's ok to power it, in a power outage.
if say the peak or surge power is 1500 watt on start up.  one site stated modified sinewave inverter efficiency was as low as 75%
with inductive loads.   does it matter if it is  120 volt 60Hz or a 240 volt 50Hz inverter set-up? as to the efficiency in quotation.   
can an AC line filter help the efficiency?
-this is about powering Refrigerators in a power outage from 12 or 24 v deep-cycle battery for 1 or 2 hrs.
NiHaoMike:
You'll ideally want V/Hz ramp up to eliminate inrush, but I'm not aware of any cheap inverters nowadays with that feature. Vector had just that in the mid 2000s, but they apparently ran into patent issues and had to discontinue it.
james_s:
I've never measured the efficiency, but inverters will typically run motors ok, even cheap modified sine wave inverters. The motor will be noisier than usual though and I do suspect the efficiency is lower. A pure sine inverter would certainly be preferable, they are not especially exotic or expensive anymore. I think I paid around $100 for the 300W continuous model I have.
BrianHG:
Cheap modified sine wave inverters have trouble with startup torque with most induction motors, even if the inverter is a continuous 1500 watt unit.  If your fridge has a normal induction motor compressor, every time it switches on, if it is a relay type thermostat switch, you may end up in a situation where your inverter will not deliver the required torque to get the compressor running before that stalled motor's high current knocks out the inverter's over current protection.
Ed.Kloonk:

--- Quote from: jonovid on June 06, 2022, 06:12:06 pm ---efficiency of the inverter generally ranges from 95 to 98% as stated by some? but is this true of most cheaper modified sinewave inverters?
if I have a 300 watt AC refrigerator,  is a modified sinewave inverter rated at a continuous 600 watt's ok to power it, in a power outage.
if say the peak or surge power is 1500 watt on start up.  one site stated modified sinewave inverter efficiency was as low as 75%
with inductive loads.   does it matter if it is  120 volt 60Hz or a 240 volt 50Hz inverter set-up? as to the efficiency in quotation.   
can an AC line filter help the efficiency?
-this is about powering Refrigerators in a power outage from 12 or 24 v deep-cycle battery for 1 or 2 hrs.

--- End quote ---

The thing about cheap inverters and their numbers is the closer you go toward pulling the numbers it says on the box, the lifespan of the inverter diminishes.

Modified sinewave inverters can have more adverse effects on electronics.

Can I suggest if you want this for use during a zombie apocalypse, think about spending a little bit more for a better-rated, pure sine wave one. It wont become the weak link when the chips are down and with a bit of extra capacity may allow a phone or torch to be charged as well.

Navigation
Message Index
Next page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod