Unstable PIP-5048GK frequency?

(As posted earlier in my build thread)

An issue I'm having is the quality of the power signal that is generated by the PIP5048-GK. I've had LED lights in most of the house for a while now, but the Filament LED's that I have give a lot of flickering. It also happens with halogen bulbs, yet other LED's with some built-in electronics seems to have little to no issues.

I didn't give much attention to it when buying the inverter, but could it be that the PIP5048-GK being a PF 1.0 unit is giving me issues?




I think I have most settings right, though I could change the mode from UPS to appliance (it just seems more logical to have it in UPS, so there's no power interuption?)




To give you an idea of the loads currently connected:
- almost all indoor lighting, mostly LED or Halogen behind dimmers. Consumption ranging from a few W to 150W.
- 1 server @ 180 W, 1 pc monitoring the PIP inverter and Batrium setup @ 65 W and my own desktop @ 150W.
- central ventilation unit @ 40W
- TV set and digital TV box @ 20W idle, 200W load.
- some small standby consumption like alarm clocks, phone chargers, etc...
Total load sits between 400 and 600 Watt for most of the day (the VA apparent power sitting a little higher at 450 - 700 VA).

When measuring the frequency with a multimeter, I noticed it's giving me all sorts of readings but not 50 Hz.
Is the inverter part simply not good enough?

Giving you what type of readings? What multimeter?

Also switch to appliances mode. Its 20ms switching so should be fast enough

It's a UNI-T UT204A multimeter. It starts by reading 50 Hz when I connect it to a wall socket (which is not in the video), but then it jumps to the 160 - 180 Hz range.
It is currently running in Line mode, with the solar generation going to the batteries.


I've switched to appliance mode now.

The unit is a high frequency inverter and this then depends on any surges that connected appliances may present to the unit, which may result in a lot of voltage sag until the surge is over. This is possibly what you are seing.

If the frequency varied in the >50Hz range you would not really see any noticable visual effect with the eye, if anything the higher the frequency the less chance you actually have of noticing any 'flicker' from an LED which may not have any capacitance and would flicker at 100Hz.. if the line frequency was 160Hz the half wave flicker would be 320Hz and near on impossible to see with stationary objects.

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Also, in line (UPS) mode the inverter is supplying the loads, while in 'appliance' mode it is effectively in bypass and a switch over would be noticable due to the timing of over half a cycle to switch. If your server is happy (should be if the power supply is decent) with the 10-20mS switch over time appliance mode should eliminate the bulk of the idle load losses.

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Your multimeter is also possibly picking up and reading harmonics on top of the base 50Hz waveform, which is likely originating from something you have plugged in. Unplug everything from the unit and measure the frequency and it should be stable at 50Hz. Incrementally plug things in and you will find out what is creating the harmonics.