Outback psx-240 standby power use

Estragon

Does anyone know what the standby or idle power use is on an Outback psx-240 autotransformer? I'll be using for a submersible pump, and am trying to figure out if it needs to be somewhere handy to turn it on and off. Also, does the fan run much and if so, is it noisy?

Thanks

mike95490

I think they claim a dozen watts loss or so, it's one of the better/efficient transformers. The fan cycle rate will depend on the size of the pump, small pump, no fan, large pump, more run time. The noise it makes, I don't know about.

H2SO4_guy

My PSX-240 runs 10-12 watts according to the Kill-A-Watt meter. About 28 - 30 watts with only the heat pump on it turned off.

Estragon

Okay, thanks. 10-12 watts isn't bad at all. It'll only be on during the day anyway, as we switch from 7 kw 48v system to low watt 12v system at night.

Constantine Faller

Thanks for these comments, even if dated. This prompts consideration and the possibility for a load actuated contactor on the 110 AC input to control on/off.

mike95490

If you are going to be switching that transformer on and off frequently, note that it presents a hefty load to the inverter each time the magnetic core charges up.  Repeat enough and it could be hard on a small inverter.  Something like a pre-charge or soft start might be worth looking.

Saggys

I have a Trace Engineering T240 3.9kva rated auto transformer that consumes 14 watt hours. Not an Outback but similiar.

Ralph Day

I had a T240 running a 240vac submersible well pump.  Xantrex 4048 inverter.  When the pump would cycle and turn on the  auto trans at the same time the colour would dissapear and the picture shrink inwards from the edges of the tv set (CRTube type).  I once saw the Xantrex status meter hit 45 amps ac when this happened (as high as it would read).  The tv eventually died and I replaced the water pump with a Grundfos soft starter.  Much easier on equipment not having that incredible surge on startup.

I still use the autotransformer(s) for running my mini split heatpumps,, but in an always on mode when heating or cooling.

Constantine Faller

mike95490 said:

If you are going to be switching that transformer on and off frequently, note that it presents a hefty load to the inverter each time the magnetic core charges up.  Repeat enough and it could be hard on a small inverter.  Something like a pre-charge or soft start might be worth looking.

Thanks Mike. Same heft to the inverter whether the 240 side is loaded or not? Inverter is a Trace SW4024. 240 load to be Mitsubishi 20,000 btu mini-split drawing 18 amps. We are considering delay-starting the load side while the core charges up.

mike95490

Split phase inverters have a imbalance factor. XW's I think can handle 75% No idea about other brands