Controller Problem
Archiver
Posts: 46,084
I have developed a a couple of boards that I am using for industrial
control. The problem I am having is my stamp wants to reset after an
AC motor starter is energized. The way the boards are made I have
12VDC coil relay that are PCB mount and are driven by a transistor
that is driven by the stamp. Through a set of NO contact on the PCB
mount relay I am turning on a bigger motor starter. I have
disconnected all leads from the motor starter and have supplied the
stamp power by an external source. After pressing the starter in by
hand I still get the reset.
I normally use the boards as timers counter etc in a control cabinet
not to directly control an AC motor contactor. I have had this
problem 1 time before and used a isolation contactor(solid state)to
remedy the problem. I know I am picking up noise from the contacts
when they switch but remeding the problem is above my head. I have
all inputs on the boards opticaly isolated but not the outputs. I
don't think this will help in this situation? Also for information
the motor contactor is supplying power to a 480V 2HP motor.
Any help is much appreciated.
Mark Waddell
control. The problem I am having is my stamp wants to reset after an
AC motor starter is energized. The way the boards are made I have
12VDC coil relay that are PCB mount and are driven by a transistor
that is driven by the stamp. Through a set of NO contact on the PCB
mount relay I am turning on a bigger motor starter. I have
disconnected all leads from the motor starter and have supplied the
stamp power by an external source. After pressing the starter in by
hand I still get the reset.
I normally use the boards as timers counter etc in a control cabinet
not to directly control an AC motor contactor. I have had this
problem 1 time before and used a isolation contactor(solid state)to
remedy the problem. I know I am picking up noise from the contacts
when they switch but remeding the problem is above my head. I have
all inputs on the boards opticaly isolated but not the outputs. I
don't think this will help in this situation? Also for information
the motor contactor is supplying power to a 480V 2HP motor.
Any help is much appreciated.
Mark Waddell
Comments
mwaddell@s... writes:
> I normally use the boards as timers counter etc in a control cabinet
> not to directly control an AC motor contactor. I have had this
> problem 1 time before and used a isolation contactor(solid state)to
> remedy the problem. I know I am picking up noise from the contacts
> when they switch but remeding the problem is above my head. I have
> all inputs on the boards opticaly isolated but not the outputs. I
> don't think this will help in this situation? Also for information
> the motor contactor is supplying power to a 480V 2HP motor.
>
> Any help is much appreciated.
>
I would suggest you get the motor controller off the PCB, if that is where it
is.
The inductive kick of that thing is enough to reset the Stamp.
Alternatively, get the Stamp away from the controller. Do you have a clamp
diode on the
transistor cthat closes the 12VDC relay?
Sid
[noparse][[/noparse]Non-text portions of this message have been removed]
> In a message dated 12/6/2003 12:59:39 PM Eastern Standard Time,
> mwaddell@s... writes:
>
>
> > I normally use the boards as timers counter etc in a control
cabinet
> > not to directly control an AC motor contactor. I have had this
> > problem 1 time before and used a isolation contactor(solid state)
to
> > remedy the problem. I know I am picking up noise from the
contacts
> > when they switch but remeding the problem is above my head. I
have
> > all inputs on the boards opticaly isolated but not the outputs.
I
> > don't think this will help in this situation? Also for
information
> > the motor contactor is supplying power to a 480V 2HP motor.
> >
> > Any help is much appreciated.
> >
>
> I would suggest you get the motor controller off the PCB, if that
is where it
> is.
> The inductive kick of that thing is enough to reset the Stamp.
> Alternatively, get the Stamp away from the controller. Do you have
a clamp diode on the
> transistor cthat closes the 12VDC relay?
>
> Sid
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
The controller and contactor are already seperate they are mounted in
a control cabinet. They do have a common back plane they are mounted
to. I did move the stamp away from the contactor and this helps. I
also moved the power supply and this seems to help even more. I
don't have a clamp diode on the transistor but when I disconnect the
board with the transistor it helps none.
I have a transformer that is dropping the 480 to 120 for a small
switching power supply. I can get the machine to run if I use a 110
outlet instead of the transformer. I still have to move the power
suply away from the contactor though.
Mark
mwaddell@s... writes:
> The controller and contactor are already seperate they are mounted in
> a control cabinet. They do have a common back plane they are mounted
> to. I did move the stamp away from the contactor and this helps. I
> also moved the power supply and this seems to help even more. I
> don't have a clamp diode on the transistor but when I disconnect the
> board with the transistor it helps none.
>
Good. You need a clamp diode on the transistor. The inductive kickback from
the relay could burn it out. Connect across relay, cathode to plus side of
relay, anode to ground. Next thing - is the 12 volts for the relay an isolated
supply, or is it part of the power supply that is powering the Stamp?
Sid
[noparse][[/noparse]Non-text portions of this message have been removed]
>AC motor starter is energized. The way the boards are made I have
>12VDC coil relay that are PCB mount and are driven by a transistor
>that is driven by the stamp. Through a set of NO contact on the PCB
>mount relay I am turning on a bigger motor starter. I have
>disconnected all leads from the motor starter and have supplied the
>stamp power by an external source. After pressing the starter in by
>hand I still get the reset.
Have you increased the size of the capacitor on your 5 volt supply
to >100uF in parallel with smaller values tantalum or ceramic, and
also either connect the ATN input to ground, or pull it down with a
resistor ~1kohm?
-- Tracy
> I have developed a a couple of boards that I am
> using for industrial
> control. The problem I am having is my stamp wants
> to reset after an
> AC motor starter is energized. The way the boards
> are made I have
> 12VDC coil relay that are PCB mount and are driven
> by a transistor
> that is driven by the stamp. Through a set of NO
<trimmed>
Mark, do you have a resistor between the stamp and the
transistor used to pwoer the relay?
> remedy the problem. I know I am picking up noise
> from the contacts
> when they switch but remeding the problem is above
> my head. I have
<trimmed>
You could try placing a diode in reverse of the coil
leads on the relay.
=====
Chris Savage
Knight Designs
324 West Main Street
Montour Falls, NY 14865
(607) 535-6777
http://www.knightdesigns.com
__________________________________
Do you Yahoo!?
New Yahoo! Photos - easier uploading and sharing.
http://photos.yahoo.com/
<knight_designs@y...> wrote:
> --- mwaddell2 <mwaddell@s...> wrote:
> > I have developed a a couple of boards that I am
> > using for industrial
> > control. The problem I am having is my stamp wants
> > to reset after an
> > AC motor starter is energized. The way the boards
> > are made I have
> > 12VDC coil relay that are PCB mount and are driven
> > by a transistor
> > that is driven by the stamp. Through a set of NO
>
> <trimmed>
>
> Mark, do you have a resistor between the stamp and the
> transistor used to pwoer the relay?
>
> > remedy the problem. I know I am picking up noise
> > from the contacts
> > when they switch but remeding the problem is above
> > my head. I have
>
> <trimmed>
>
> You could try placing a diode in reverse of the coil
> leads on the relay.
>
>
>
> =====
> Chris Savage
> Knight Designs
> 324 West Main Street
> Montour Falls, NY 14865
> (607) 535-6777
>
> http://www.knightdesigns.com
>
> __________________________________
> Do you Yahoo!?
> New Yahoo! Photos - easier uploading and sharing.
> http://photos.yahoo.com/
Yes I do have a resistor between the transister and the stamp. The
problem is from the arcing of the contacts of the 3 phase 480 volt
line. I have disconnected the board that interfaces to the motor
starter thew only thing the 2 circuits have in common is a common
ground. I have the problem even when I push in the contactor by
hand. The coil is not being used when I do this.
> In a message dated 12/6/2003 1:56:31 PM Eastern Standard Time,
> mwaddell@s... writes:
>
>
> > The controller and contactor are already seperate they are
mounted in
> > a control cabinet. They do have a common back plane they are
mounted
> > to. I did move the stamp away from the contactor and this
helps. I
> > also moved the power supply and this seems to help even more. I
> > don't have a clamp diode on the transistor but when I disconnect
the
> > board with the transistor it helps none.
> >
>
> Good. You need a clamp diode on the transistor. The inductive
kickback from
> the relay could burn it out. Connect across relay, cathode to
plus side of
> relay, anode to ground. Next thing - is the 12 volts for the
relay an isolated
> supply, or is it part of the power supply that is powering the
Stamp?
>
> Sid
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
The supply is not isolated. I have a transformer dropping 480V to
120V and then it goes to a switching power supply 24VDC. The power
supply for the stamp is a LM7805 that is being fed by the 24VDC
supply.
> >The problem I am having is my stamp wants to reset after an
> >AC motor starter is energized. The way the boards are made I have
> >12VDC coil relay that are PCB mount and are driven by a transistor
> >that is driven by the stamp. Through a set of NO contact on the
PCB
> >mount relay I am turning on a bigger motor starter. I have
> >disconnected all leads from the motor starter and have supplied
the
> >stamp power by an external source. After pressing the starter in
by
> >hand I still get the reset.
>
> Have you increased the size of the capacitor on your 5 volt supply
> to >100uF in parallel with smaller values tantalum or ceramic, and
> also either connect the ATN input to ground, or pull it down with
a
> resistor ~1kohm?
>
> -- Tracy
The capacitor look close to what I have. Pulling the ATN line to
ground I haven't done. I won't be back at work till monday
hopefully! I will try this then.
> Yes I do have a resistor between the transister and
> the stamp. The
> problem is from the arcing of the contacts of the 3
> phase 480 volt
> line. I have disconnected the board that interfaces
> to the motor
> starter thew only thing the 2 circuits have in
> common is a common
> ground. I have the problem even when I push in the
> contactor by
> hand. The coil is not being used when I do this.
I apologize, I thought you were disconnecting the
power (AC) circuitry altogether and the relay was the
only thing still connected. I see Tracy had a couple
of good suggestions.
=====
Chris Savage
Knight Designs
324 West Main Street
Montour Falls, NY 14865
(607) 535-6777
http://www.knightdesigns.com
__________________________________
Do you Yahoo!?
New Yahoo! Photos - easier uploading and sharing.
http://photos.yahoo.com/
I do not know what the original question was, I must have missed it earlier.
I routinely control 480 3PH circuitry with Stamps.
You most likely need more filtering on the Stamp Power and I/O lines.
I optically isolate everything and use Digital Noise Filters on all I/O lines.
I use Murata-Erie DSS306-55Y5547. It looks like a 3 legged Capacitor. Ground
the middle leg and feet the signal through the other 2 legs.
This adds some costs to the design, but it is loads cheaper then the damage
possible from a runaway machine, due to a locked up controller. (Or a slick
Boston Lawyer.)
Let me know if you need anymore help.
Alan Bradford
Plasma Technologies
www.plasmatechnologies.com
--- mwaddell2 <mwaddell@s...> wrote:
> Yes I do have a resistor between the transister and
> the stamp. The
> problem is from the arcing of the contacts of the 3
> phase 480 volt
> line. I have disconnected the board that interfaces
> to the motor
> starter thew only thing the 2 circuits have in
> common is a common
> ground. I have the problem even when I push in the
> contactor by
> hand. The coil is not being used when I do this.
I apologize, I thought you were disconnecting the
power (AC) circuitry altogether and the relay was the
only thing still connected. I see Tracy had a couple
of good suggestions.
=====
Chris Savage
Knight Designs
324 West Main Street
Montour Falls, NY 14865
(607) 535-6777
http://www.knightdesigns.com
[noparse][[/noparse]Non-text portions of this message have been removed]