Clive603
Titanium
- Joined
- Aug 2, 2008
- Location
- Sussex, England
R900
I have a 10 hp rated Drives Direct "plug and play" 240 (nom) single phase in, 440 V three phase output box with the separate line filter box (then?) sold to make the supply suitable for use with CNC machines. Wired three phase and neutral, just like a proper 3 phase supply. I don't use the VFD function. Its permanently set to 50 hz.
I use it just like proper 3 phase supply. All my machines are directly connected to a 440 V whole shop bus and retain the original contactors.
It all just works and has been doing so for rather more than a decade. Even the splendidly steam punk oil immersed contactor set up controlling the two speed motor on my wartime P&W model B behaves just fine. Main limitation is starting power. Drives Direct advise that motors of no more than half the rated power be used. I've unilaterally derated to 1/3 rd. Seems wise to me and partially vindicated by the odd grunt when running up my Smart & Brown 1024 lathe, which has no clutch, with a decent size job mounted. I've had 9 hp worth of motors running at a time which didn't seem to faze the box.
Hafta say it was supposed to be a temporary expedient as the box popped up on E-Bay for half new price when I was having a fit of bad temper with the noise from my rotary converter and the difficulties of actually getting an electrician to connect up the £5,000 worth of three phase incomer the power company (eventually) ran to the house for me.
Nowt so permanent as a temporary job!
I'd not run large or recipriocating a compressor off it (although its happy with my Hydrovane 502). Dedicated VFD for that with the boost parameter enabled so it runs up to speed rather than be simply kicked with full volts..
My rotary converter was a MotorRun static converter box with a hefty three phase motor bolted on the side. Worked fine once I got the capacitors trimmed. But noisy and the current phasing was variable.
The older I get (68 now) the more favourably I view paying more for just works properly rather than hours of DIY to make £1 do the work of £10!
I don't trust the import 240 to 380 VFD boxes. I suspect the input rectifier configuration doesn't give enough voltage headroom to work properly. Like the rash of cheap conversions done on use industrial boxes back in the day when all this was a novel thing.
Clive
I have a 10 hp rated Drives Direct "plug and play" 240 (nom) single phase in, 440 V three phase output box with the separate line filter box (then?) sold to make the supply suitable for use with CNC machines. Wired three phase and neutral, just like a proper 3 phase supply. I don't use the VFD function. Its permanently set to 50 hz.
I use it just like proper 3 phase supply. All my machines are directly connected to a 440 V whole shop bus and retain the original contactors.
It all just works and has been doing so for rather more than a decade. Even the splendidly steam punk oil immersed contactor set up controlling the two speed motor on my wartime P&W model B behaves just fine. Main limitation is starting power. Drives Direct advise that motors of no more than half the rated power be used. I've unilaterally derated to 1/3 rd. Seems wise to me and partially vindicated by the odd grunt when running up my Smart & Brown 1024 lathe, which has no clutch, with a decent size job mounted. I've had 9 hp worth of motors running at a time which didn't seem to faze the box.
Hafta say it was supposed to be a temporary expedient as the box popped up on E-Bay for half new price when I was having a fit of bad temper with the noise from my rotary converter and the difficulties of actually getting an electrician to connect up the £5,000 worth of three phase incomer the power company (eventually) ran to the house for me.
Nowt so permanent as a temporary job!
I'd not run large or recipriocating a compressor off it (although its happy with my Hydrovane 502). Dedicated VFD for that with the boost parameter enabled so it runs up to speed rather than be simply kicked with full volts..
My rotary converter was a MotorRun static converter box with a hefty three phase motor bolted on the side. Worked fine once I got the capacitors trimmed. But noisy and the current phasing was variable.
The older I get (68 now) the more favourably I view paying more for just works properly rather than hours of DIY to make £1 do the work of £10!
I don't trust the import 240 to 380 VFD boxes. I suspect the input rectifier configuration doesn't give enough voltage headroom to work properly. Like the rash of cheap conversions done on use industrial boxes back in the day when all this was a novel thing.
Clive
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