Way to complicated. The “half wave load” is as described earlier. It is a cheap way to get a hair drier (or other heater) with a three-way switch to have air, half power and full power. The half power routes the hot side through a diode so that the heating element only get half power. Full power is no diode. This can cause trouble with some inverters, and I am sure is a terrible (noisy) load on any AC line, but it is cheap and they don’t care about the side affects.
David > On Dec 21, 2024, at 2:05 PM, pieter offgridenterprises.org via RE-wrenches > <[email protected]> wrote: > > Nomenclature! After all of this discussion it sounds like “half wave load” is > being used to describe a load that is only using one of the two 120 volt legs > a standard 120/240 split phase inverter provides. That being the case the AC > output current rating should be looked at. For example an inverter rated at > 9KW might have a 37.5 amp max output current rating. That means the inverter > is only rated to supply 37.5 amps per leg. So in other words 120VAC X 37.5 > amps =4500 Watts, (at unity power factor) or 240AC X 37.5 amps =9000Watts (at > unity power factor). If a load is connected on one of the two 120 volt line > to Neutral legs and the current exceeds 37.5amps the load will exceed the > inverter rating. If the power factor is not 1, then the output watts can be > less than the output VA.. It is possible that what is being referred to as a > “half wave load” could more accurately be described as an unbalanced load. > That being the case the total load on the inverter may be less than the > specified load rating, but the load current on one “leg” maybe more than the > inverter rated output current. If the leg currents are measured and found not > be reasonably balanced it may be possible to correct the issue by re > arranging circuit breakers in the MDP. > Pieter Huebner > Project Manager > Off Grid Enterprises > > > From: RE-wrenches <[email protected] > <mailto:[email protected]>> On Behalf Of Jay via > RE-wrenches > Sent: Saturday, December 21, 2024 10:55 AM > To: RE-wrenches <[email protected] > <mailto:[email protected]>> > Cc: Jay <[email protected] <mailto:[email protected]>> > Subject: Re: [RE-wrenches] 1/2 wave loads > > I can’t remember if I sent the update. > > We identified the load as a Japanese bidet. Once unplugged everything is > working normally. > > So whatever people want to call the 1/2 wave. It’s what multiple OEMS call > it. > > If I can find an oscilloscope I’ll send along what the wave form looks like. > > Jay > > > > > On Dec 19, 2024, at 10:11 AM, Jesse Dahl via RE-wrenches > <[email protected] > <mailto:[email protected]>> wrote: > > I think about resistive loads as “in-phase”. Half-wave seem like they would > a load with a diode blocking one side of the waveform. > Sent from my iPhone > > > On Dec 18, 2024, at 3:03 PM, Jay via RE-wrenches > <[email protected] > <mailto:[email protected]>> wrote: > > > I will add that I’ve heard privately off list that it’s actually smaller > loads that seem to be the issue. > > And larger 1500 watt electric heaters seem to work ok. > > I’m wondering if anyone else has come across this issue and I guess more > importantly is there a fix? > > Jay > > > On Dec 18, 2024, at 1:52 PM, Jay <[email protected] > <mailto:[email protected]>> wrote: > > > Here is what I understand 1/2 wave loads to be. > > As I understand it, Heater loads are the main issue. > > Toasters, toaster ovens, hair dryers, aquarium/terraium heaters etc. > > But if there are other things pls let us know > > Jay > > > On Dec 18, 2024, at 1:34 PM, GLBCC via RE-wrenches > <[email protected] > <mailto:[email protected]>> wrote: > > > What is a half wave load? > > On Dec 18, 2024 13:35, Jay via RE-wrenches <[email protected] > <mailto:[email protected]>> wrote: > Hi all. > > I’ve recently been made aware that the fortress inverter isn’t too happy with > 1/2 wave loads. > > I’m wondering if this is an issue with the AIO or solark? > > Thanks in advance > > Jay > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > <http://re-wrenches.org/> > List Address: [email protected] > <mailto:[email protected]> > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > <http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org> > There are two list archives for searching. 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