Hang on here, back up a bit. Start at the beginning. What is the input voltage on the name plate for the entire machine? What voltage are you feeding to the machine? For example if the machine's name plate calls for 400v, but you are feeding it 460v, that would explain having about 30v too high voltage at the servo's transformer. Does the machine have a large transformer in it similar to this that the main power goes through? https://image.hgrinc.com/inventory/0823/0423194/20230804110345443_L.JPG The different taps on a large transformer like that would allow you to adjust the main voltage to what is needed. (Not all machines include this though.)
No, you cannot power an 8i20 with AC voltage, it must be fed DC. All servo drives that run off AC power have the rectifier and capacitors for converting the AC to DC built in. (Therefore they are usually much larger and more expensive than an equivalent DC powered drive.) Todd Zuercher P. Graham Dunn Inc. 630 Henry Street Dalton, Ohio 44618 Phone: (330)828-2105ext. 2031 -----Original Message----- From: Viesturs Lācis <viesturs.la...@gmail.com> Sent: Tuesday, June 25, 2024 5:02 AM To: Enhanced Machine Controller (EMC) <emc-users@lists.sourceforge.net> Subject: Re: [Emc-users] Power source for 8i20 [You don't often get email from viesturs.la...@gmail.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] [EXTERNAL EMAIL] Be sure links are safe. piektd., 2024. g. 21. jūn., plkst. 15:52 — lietotājs Peter Wallace (<p...@mesanet.com>) rakstīja: > > On Fri, 21 Jun 2024, Viesturs L?cis wrote: > > > Date: Fri, 21 Jun 2024 14:08:00 +0300 > > From: "[UTF-8] Viesturs L?cis" <viesturs.la...@gmail.com> > > Reply-To: "Enhanced Machine Controller (EMC)" > > <emc-users@lists.sourceforge.net> > > 1) should I place rectifier bridge + capacitor for each drive > > separately or feed them from one source? > > One source is better > Ok, got it! > > > 2) what is suggested max ripple voltage for 8i20? > More an issue with the filter capacitors, the 8I20s current loop will > track any ripple (which should be slight if you have 3 phase power) > I added those motor power ratings together, it is approximately 4kW. I found an online site that calculates required capacitance to achieve required ripple voltage. My assumption was 10V ripple (and even that requires 10mF capacitors). Is that acceptable value? > > > 3) do I understand correctly that rectifying 3phase 380VAC will > > result in something around 540VDC which exceeds 8i20 limits and I > > should use 1phase 230VAC (adding transformers seems to reduce AC > > voltage seems like unjustified cost)? > > Yes, the 8I20 expects rectified 230V single phase or better, rectified > 208V 3 phase. Rectifed 380VAC will cause an explosion... > I went back to machine and found out that servodrive power input is supposed to be 3phase 210VAC (210V between phases) - I had not paid much of attention to the transformer at the bottom of the cabinet. And under a layer of dust I found 3 wires marked as 210V and in electric wiring diagram it also was marked as 210VAC (between phases) and only destination of this output is servodrive power input. The thing is - I checked with multimeter and it was showing nice and stable 232,2 VAC between phases (+/- 0,1V between any of 3 phases, but I have no idea about the possible error of multimeter itself although I would assume it to be less than 1V). From servodrive manual it seems to me that this is a version with 3phase 200VAC input. BTW If actual input seems to be 30V higher than rated, it seems to be the reason for A.40 "overvoltage" error. Is there anything I can do to fix it? I have no idea. because it is direct output of transformer. Anyway, the question is - how bad is it for 8i20 to rectify 3-phase 2302VAC? > > What are your motor voltage ratings? > I do not know where to check that. Nameplate in motor itself does not say that. From a table in servodrive manual I found that for Axis motor rated output is 150W and rated current is 3A which make me think that rated voltage would be 50V. Is it correct to calculate like that a 3phase motor? (IMHO this method should be fine for single phase). Viesturs _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
