I have recently purchased a second hand sdmo booster 2000 inverter generator and have a question about the Frequency. Uk spec 230/240v and 50 HZ
I have the UK equivalent of the kill-a-watt meter and if set to the frequency function with no load on the genny it shows 21HZ , put a load on and the frequency reading fluctuates between 04-87 HZ.
If I use the same meter on a mains socket it reads 50Hz as expected, It also shows 50Hz as the output under load from some inverters powered by
batteries in my caravan (this gives an indication that the meter works).
I went to look at another identical model generator for sale second hand (from a different person) and this time took the "kill-a-watt" meter with me and backed out of the purchase due to the same readings, i.e 21Hz on load and fluctuating Hz onload.
When back home , I was wondering if the floating neutral on the generators was confusing the kill-a-watt meter .So I made up a test extension lead with the neutral and earth conected and this time the no load frequency shows as 41Hz and the on load frequency shows as fluctuating between 40-70Hz .
The tests where done with both a 1000w fan heater (so resistive load) and an old power drill (300w), the frequency fluctuations showed as greater with the power drill.
It could be that both generators hundreds of miles apart have developed the same fault, the model of generator could be suspect or my method of testing could be suspect!!
So my questions are ,
1) should I expect to see a real stable (as advertised) 50hz (or 60hz on a USA model) output of an inverter generator ?
2) Is a kill-a-watt meter a suitable way of testing the frequency of a generator output.
3) Would a fluctuating frequency be likely to damage items plugged in?
Cheers, Shady
I have the UK equivalent of the kill-a-watt meter and if set to the frequency function with no load on the genny it shows 21HZ , put a load on and the frequency reading fluctuates between 04-87 HZ.
If I use the same meter on a mains socket it reads 50Hz as expected, It also shows 50Hz as the output under load from some inverters powered by
batteries in my caravan (this gives an indication that the meter works).
I went to look at another identical model generator for sale second hand (from a different person) and this time took the "kill-a-watt" meter with me and backed out of the purchase due to the same readings, i.e 21Hz on load and fluctuating Hz onload.
When back home , I was wondering if the floating neutral on the generators was confusing the kill-a-watt meter .So I made up a test extension lead with the neutral and earth conected and this time the no load frequency shows as 41Hz and the on load frequency shows as fluctuating between 40-70Hz .
The tests where done with both a 1000w fan heater (so resistive load) and an old power drill (300w), the frequency fluctuations showed as greater with the power drill.
It could be that both generators hundreds of miles apart have developed the same fault, the model of generator could be suspect or my method of testing could be suspect!!
So my questions are ,
1) should I expect to see a real stable (as advertised) 50hz (or 60hz on a USA model) output of an inverter generator ?
2) Is a kill-a-watt meter a suitable way of testing the frequency of a generator output.
3) Would a fluctuating frequency be likely to damage items plugged in?
Cheers, Shady