Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 05/03/2016 12:39 PM, andy pugh wrote: > On 3 May 2016 at 18:16, Jon Elson wrote: >> Are these name-brand SSRs >> or some china noname units you got on eBay? > Well, the labels say "Fotek" but then the labels are peeling off, and > I today found web pages talking about

Re: [Emc-users] SSR Issues, Thyristor dv/dt

This is clearly ancient history but: many years ago in a time before time a guy needed a CC device to light orchard heaters. Nichrome coiled elements in series; must touch off either oil or propane. It used an off-the-shelf SCR feeding (ugh!) an 240 v to 440 v transformer. Indeed the

Re: [Emc-users] Early 80's Matsuura conversion.

Couple of things I had forgotten in the previous big conversion. (using opto22 boards..) -Dc modules are polarity sensitive. (who knew? ;) ) (and when you reverse them - they have a diode so they are 'just on' ) -The 24 module opto22 boards need to have a jumper soldered in to power them

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 3 May 2016 at 18:16, Jon Elson wrote: > Are these name-brand SSRs > or some china noname units you got on eBay? Well, the labels say "Fotek" but then the labels are peeling off, and I today found web pages talking about fake Fotek SSRs. Having taken one apart, the

Re: [Emc-users] SSR Issues, Thyristor dv/dt --> Inrush current?

> > If you need limiting of inrush current I guess a transistor connected as a > > current source would be the perfect solution for this? Or is it against > > surge voltage? > > The reason I need inrush current limiting is mainly so that the lights > and fridge stay on when I turn on the lathe

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 05/03/2016 07:46 AM, andy pugh wrote: > On 3 May 2016 at 13:37, Gene Heskett wrote: >>> And does the "fail to turn off" problem description include not >>> turning off ever again, even when removed from the circuit and from >>> all power? >> Generally yes, its an avalanche

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 05/03/2016 06:14 AM, andy pugh wrote: > I could pick a couple of these up today, though it is an 80-mile round > trip. I wonder if they would work better? > http://www.rapidonline.com/kudom-ksim380d25-l-panel-mount-ssr-4-32vdc-48-440vac-25a-load-led-zero-cross-60-1598 > (For a total of 2kW of

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 05/03/2016 05:42 AM, andy pugh wrote: it sounds like your derating should have been sufficient. The fact that an SSR with a SIZEABLE resistor in series with it failed is awfully suspicious! Are these name-brand SSRs or some china noname units you got on eBay? While the nonlinear nature of

Re: [Emc-users] How to assign values to pwmgen parameters(duty-cycle, frequency, etc, ) from GUI ?

On 3 May 2016 at 16:12, adit bhargava wrote: > Thank you very much Andy. I forgot to add tristate_float to thread. Now, I > addeed to my base-thread and the output comes now on CRO. You should add it to the servo-thread really, there is no need to update the value at

Re: [Emc-users] How to assign values to pwmgen parameters(duty-cycle, frequency, etc, ) from GUI ?

On 3 May 2016 at 15:30, adit bhargava wrote: > Yes Andy, I also checked the documentation of pwmgen is wrong.pwm-freq is a > hal pin > I did these steps as suggested by you but the output on CRO is not as it > should be according to frequency of 150 Hz and duty cycle of

Re: [Emc-users] How to assign values to pwmgen parameters(duty-cycle, frequency, etc, ) from GUI ?

Thank you very much Andy. I forgot to add tristate_float to thread. Now, I addeed to my base-thread and the output comes now on CRO. However, now I also want the duty cycle to be calculated, My T-On is always 2 ms I have to use the Signal frequency (which I got through GUI ) Every time to

Re: [Emc-users] How to assign values to pwmgen parameters(duty-cycle, frequency, etc, ) from GUI ?

Yes Andy, I also checked the documentation of pwmgen is wrong.pwm-freq is a hal pin I did these steps as suggested by you but the output on CRO is not as it should be according to frequency of 150 Hz and duty cycle of 29.9% (pulses of T-on = 2ms and T-off = 4.7 ms) Are below steps correct? I

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 3 May 2016 at 15:12, John Kasunich wrote: > The vast majority of the AC drives on the market don't even have a > pre-charge contactor. When power is applied, the bus immediately > charges thru the resistor. And that would be perfectly acceptable in my application too,

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On Tue, May 3, 2016, at 10:00 AM, andy pugh wrote: > If there is no reason not to leave the pre-charge relay closed during > operation, I could even use the existing mechanical relay that brings > in the discharge resistor. Is there a reason to switch-out the > precharge relay once the main

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 3 May 2016 at 14:31, John Kasunich wrote: > > Is there any particular reason you are using SSRs instead of > regular contactors? I like contactors because they are rugged > and pretty much immune to overvoltage, dv/dt, and di/dt problems. Mainly it is a matter of

Re: [Emc-users] Any Interest or Ideas for a Linuxcnc Fest, 2016 ?

The area around Tech Shop and the Best Western is modern suburbia, nothing like downtown Detroit. The Best Western itself is an old school full service large motel complex. Well maintained but looks like something from the 1980s era. Location is not walkable except for the on site restaurant and

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On Tue, May 3, 2016, at 09:34 AM, andy pugh wrote: > On 3 May 2016 at 14:27, Erik Christiansen wrote: > > Yup, a MOV goes across the triac, to clamp voltage spikes. > > When you say "Across" do you mean across the output terminals of the > SSR, or between the live

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On Tuesday 03 May 2016 08:46:07 andy pugh wrote: > On 3 May 2016 at 13:37, Gene Heskett wrote: > >> And does the "fail to turn off" problem description include not > >> turning off ever again, even when removed from the circuit and from > >> all power? > > > > Generally yes,

Re: [Emc-users] SSR Issues, Thyristor dv/dt --> Inrush current?

On 3 May 2016 at 14:00, Nicklas Karlsson wrote: > If you need limiting of inrush current I guess a transistor connected as a > current source would be the perfect solution for this? Or is it against surge > voltage? The reason I need inrush current limiting is

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 3 May 2016 at 14:27, Erik Christiansen wrote: > Yup, a MOV goes across the triac, to clamp voltage spikes. When you say "Across" do you mean across the output terminals of the SSR, or between the live terminal of the SSR and neutral? The former is easier, and I doubt

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On Tue, May 3, 2016, at 06:42 AM, andy pugh wrote: > Section 6 on page C-343 here: > https://www.omron.com/ecb/products/pdf/precautions_ssr.pdf shows a > square-wave with zero time at 0 current. But I don't understand how > that is possible with a sinusoidal input voltage. Surely the current >

Re: [Emc-users] How to assign values to pwmgen parameters(duty-cycle, frequency, etc, ) from GUI ?

On 3 May 2016 at 13:56, Nicklas Karlsson wrote: > Yes you are correct. No, actually, I am wrong. I just checked the source and the manual page is incorrect. https://github.com/LinuxCNC/linuxcnc/blob/master/src/hal/components/pwmgen.c#L503 adit: The pwm frequency

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 03.05.16 13:32, andy pugh wrote: > On 3 May 2016 at 13:29, andy pugh wrote: > > Until I googled just now I thought that this was what was meant by > > MOV. The data sheets for Varistors seem to specify an activation > > voltage and a power dissipation, but no off-state

Re: [Emc-users] SSR Issues, Thyristor dv/dt

> > > If Solid State Relay SSR happen to be a thyristor it will only allow > > > a limited dv/dt or it will fail to turn off. A common source of > > > dv/dt is inductive or maybe capacitive load and it happens because a > > > thyristor turn off at zero current although a reactive load do not > > >

Re: [Emc-users] SSR Issues

On 3 May 2016 at 13:57, Nicklas Karlsson wrote: >> You may need higher voltage rated devices, Andy. Without ANY switching >> spikes, or the EMP from a nearby lightning strike, they are seeing the >> RMS peak voltage of 338.4 volts (240 * 1.41) 100 times a second. >

Re: [Emc-users] SSR Issues, Thyristor dv/dt --> Inrush current?

On Tue, 3 May 2016 13:29:42 +0100 andy pugh wrote: > On 3 May 2016 at 12:41, Erik Christiansen wrote: > > > > The link to SSR precautions indicates that the SSR already includes a > > snubber. But page 3 of the notes says that is often not

Re: [Emc-users] How to assign values to pwmgen parameters(duty-cycle, frequency, etc, ) from GUI ?

> On 3 May 2016 at 13:20, Nicklas Karlsson wrote: > > Step generator in mesa hostmot is a speed signal and it output a square > > wave with varying frequency. > > But steplen and stepspace are parameters, so the same problem exists. > You can change the frequency

Re: [Emc-users] SSR Issues

> On Tuesday 03 May 2016 04:54:32 andy pugh wrote: > > > On 3 May 2016 at 02:51, Jon Elson wrote: > > > You should very conservatively derate the SSRs > > > in many circumstances, but especially where capacitive > > > inrush surge is possible. > > > > The PSU is powered

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 3 May 2016 at 13:37, Gene Heskett wrote: >> And does the "fail to turn off" problem description include not >> turning off ever again, even when removed from the circuit and from >> all power? > > Generally yes, its an avalanche mode failure that shorts the switching >

Re: [Emc-users] How to assign values to pwmgen parameters(duty-cycle, frequency, etc, ) from GUI ?

On 3 May 2016 at 13:20, Nicklas Karlsson wrote: > Step generator in mesa hostmot is a speed signal and it output a square wave > with varying frequency. But steplen and stepspace are parameters, so the same problem exists. You can change the frequency from HAL, but

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On Tuesday 03 May 2016 06:40:35 Erik Christiansen wrote: > On 03.05.16 10:30, andy pugh wrote: > > And does the "fail to turn off" problem description include not > > turning off ever again, even when removed from the circuit and from > > all power? > > No, dv/dt triggering is merely spurious

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 3 May 2016 at 13:29, Nicklas Karlsson wrote: > If possible I would measure voltage spike before to make sure there are any > otherwise the problems is elsewhere. I have no real reason to think that I have a voltage spike problem at all, really. I don't think I

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On Tuesday 03 May 2016 05:30:54 andy pugh wrote: > On 3 May 2016 at 10:14, Nicklas Karlsson wrote: > > If Solid State Relay SSR happen to be a thyristor it will only allow > > a limited dv/dt or it will fail to turn off. A common source of > > dv/dt is inductive or

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 3 May 2016 at 13:29, andy pugh wrote: > Until I googled just now I thought that this was what was meant by > MOV. The data sheets for Varistors seem to specify an activation > voltage and a power dissipation, but no off-state resistance > measurement to calculate the power

Re: [Emc-users] SSR Issues, Thyristor dv/dt

> On 03.05.16 12:14, andy pugh wrote: > > I could pick a couple of these up today, though it is an 80-mile round > > trip. I wonder if they would work better? > > http://www.rapidonline.com/kudom-ksim380d25-l-panel-mount-ssr-4-32vdc-48-440vac-25a-load-led-zero-cross-60-1598 > > Well, 620v peak

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 3 May 2016 at 12:41, Erik Christiansen wrote: > > The link to SSR precautions indicates that the SSR already includes a > snubber. But page 3 of the notes says that is often not sufficient, and > suggests a 440 - 470 volt varistor (MOV) as protection in a 200 - 240 >

Re: [Emc-users] SSR Issues

On Tuesday 03 May 2016 04:54:32 andy pugh wrote: > On 3 May 2016 at 02:51, Jon Elson wrote: > > You should very conservatively derate the SSRs > > in many circumstances, but especially where capacitive > > inrush surge is possible. > > The PSU is powered through a 20A

Re: [Emc-users] SSR Issues, Thyristor dv/dt

> On 03.05.16 11:42, andy pugh wrote: > > On 3 May 2016 at 10:41, Nicklas Karlsson > > wrote: > > > In other words i/C should be less than maximum allowed du/dt. > > > > I am not sure how to determine the i for this calculation. I guess I > > can find the dv/dt

Re: [Emc-users] How to assign values to pwmgen parameters(duty-cycle, frequency, etc, ) from GUI ?

On Tue, 3 May 2016 12:47:08 +0100 andy pugh wrote: > On 3 May 2016 at 12:18, adit bhargava wrote: > > Hello All, > > Please let me know how can I set the values of 'Signal frequency' to PWMGEN > > from my AXIS EMC GUI ?I changed the

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 03.05.16 12:14, andy pugh wrote: > I could pick a couple of these up today, though it is an 80-mile round > trip. I wonder if they would work better? > http://www.rapidonline.com/kudom-ksim380d25-l-panel-mount-ssr-4-32vdc-48-440vac-25a-load-led-zero-cross-60-1598 Well, 620v peak ought to give

Re: [Emc-users] How to assign values to pwmgen parameters(duty-cycle, frequency, etc, ) from GUI ?

On 3 May 2016 at 12:18, adit bhargava wrote: > Hello All, > Please let me know how can I set the values of 'Signal frequency' to PWMGEN > from my AXIS EMC GUI ?I changed the 'Intervallcontrol.xml' to add the options > in GUI for 'Signal Frequency'. > I need to use this

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 03.05.16 11:42, andy pugh wrote: > On 3 May 2016 at 10:41, Nicklas Karlsson wrote: > > In other words i/C should be less than maximum allowed du/dt. > > I am not sure how to determine the i for this calculation. I guess I > can find the dv/dt from the component

[Emc-users] How to assign values to pwmgen parameters(duty-cycle, frequency, etc, ) from GUI ?

Hello All, Please let me know how can I set the values of 'Signal frequency' to PWMGEN from my AXIS EMC GUI ?I changed the 'Intervallcontrol.xml' to add the options in GUI for 'Signal Frequency'. I need to use this value to calculate the DUTY-CYCLE and then assign it to run my software PWMGEN.

Re: [Emc-users] SSR Issues, Thyristor dv/dt

I could pick a couple of these up today, though it is an 80-mile round trip. I wonder if they would work better? http://www.rapidonline.com/kudom-ksim380d25-l-panel-mount-ssr-4-32vdc-48-440vac-25a-load-led-zero-cross-60-1598 (For a total of 2kW of servo drive a 25A device ought to be sufficient, I

Re: [Emc-users] Any Interest or Ideas for a Linuxcnc Fest 2016 ?

On 3 May 2016 at 12:00, Ron Ginger wrote: > The Best Western is near, and that whole area is Ford country, with many > office buildings and the big Ford Rouge plant. It is not in the 'real' > Detroit. It is cheaper than the hotel from last year. I am staying there. The

Re: [Emc-users] Any Interest or Ideas for a Linuxcnc Fest 2016 ?

Everyone should register. Last year we had a discount deal for presenters, but I have not heard if TechShop is doing that again. I will check into it. The Best Western is near, and that whole area is Ford country, with many office buildings and the big Ford Rouge plant. It is not in the 'real'

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 3 May 2016 at 11:42, andy pugh wrote: > > In case it helps, this is the input circuit. > https://imagebin.ca/v/2fs1b7szpsMy The SSRs are controlled by LinuxCNC > individually. That left out an important part of the circuit https://imagebin.ca/v/2fs60d4YbDyo is better.

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 3 May 2016 at 10:41, Nicklas Karlsson wrote: > In other words i/C should be less than maximum allowed du/dt. I am not sure how to determine the i for this calculation. I guess I can find the dv/dt from the component numbers on this page:

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 03.05.16 10:30, andy pugh wrote: > And does the "fail to turn off" problem description include not > turning off ever again, even when removed from the circuit and from > all power? No, dv/dt triggering is merely spurious initiation of conduction by excessively rapid increase of applied

Re: [Emc-users] SSR Issues, Thyristor dv/dt

> On 3 May 2016 at 10:14, Nicklas Karlsson wrote: > > If Solid State Relay SSR happen to be a thyristor it will only allow a > > limited dv/dt or it will fail to turn off. A common source of dv/dt is > > inductive or maybe capacitive load and it happens because a

Re: [Emc-users] SSR Issues, Thyristor dv/dt

On 3 May 2016 at 10:14, Nicklas Karlsson wrote: > If Solid State Relay SSR happen to be a thyristor it will only allow a > limited dv/dt or it will fail to turn off. A common source of dv/dt is > inductive or maybe capacitive load and it happens because a thyristor

Re: [Emc-users] SSR Issues, Thyristor dv/dt

If Solid State Relay SSR happen to be a thyristor it will only allow a limited dv/dt or it will fail to turn off. A common source of dv/dt is inductive or maybe capacitive load and it happens because a thyristor turn off at zero current although a reactive load do not have zero voltage at zero

Re: [Emc-users] SSR Issues

On 3 May 2016 at 03:04, Gene Heskett wrote: > You may have been tapped by the EMP of a nearby lightning strike, Andy. The machine has been disconnected from the mains pretty much all the time since it last worked. In fact the PSU has only been wired-in for a few weeks, and I

Re: [Emc-users] SSR Issues

On 3 May 2016 at 02:51, Jon Elson wrote: > You should very conservatively derate the SSRs > in many circumstances, but especially where capacitive > inrush surge is possible. The PSU is powered through a 20A breaker and the SSRs are rated at 40A. The anticipated peak

Re: [Emc-users] Any Interest or Ideas for a Linuxcnc Fest 2016 ?

On 3 May 2016, at 03:23, Thomas Powderly wrote: > Hi Bari, > I cant come, living in Thailand > I hope talks & demos will be documented/videoed. Living in the UK, I too am far away, so videos would be very welcome, and might also be a useful general resource for the wider community. Marcus >