I'm currently going through and integration with an old machine. For the outputs I've spec'd 1756 - OA16's which offer everything I need however there's a part in the manual that's bugging me which I cant find much info on...
Commutating voltage
4V/μs for loads > 50 mA
0.2V/μs for loads < 50 mA(2)
The commutating dv/dt of the output voltage (OUTPUT to L2) should not exceed 0.2V/μs for loads under 50 mA. The commutating dv/dt rating of the module for loads 50…500 mA (OUTPUT to L2) is
4V/μs maximum. If the commutating dv/dt rating of the TRIAC is exceeded, the TRIAC could latch on. If the commutating dv/dt rating is exceeded in the 10…50 mA range, a resistor may be added AC
across the output and L2. The purpose of this resistor is to increase the total output current to 50 mA (I=V/R). At 50 mA and above, the module has a higher commutating dv/dt rating. When adding a
resistor for the output to L2, be sure it is rated for the power that it will dissipate (P=(V**2)/R). If the commutating dv/dt rating is exceeded in the 50…500 mA range, the L1 AC waveform could be at
fault. Be sure the waveform is a good sinusoid, void of any anomalies such as distorted or flattened sections.
I understand roughly what it is saying, that the rate of voltage change can not be at any higher than the values given, however I'm having difficulty getting this info from any of my output devices.
An example of one of the outputs is AB 100-C contactors.
http://literature.rockwellautomation.com/idc/groups/literature/documents/td/100-td013_-en-p.pdf
Any help or experiences regarding this would be appreciated.
Thanks in advance, Will.
Commutating voltage
4V/μs for loads > 50 mA
0.2V/μs for loads < 50 mA(2)
The commutating dv/dt of the output voltage (OUTPUT to L2) should not exceed 0.2V/μs for loads under 50 mA. The commutating dv/dt rating of the module for loads 50…500 mA (OUTPUT to L2) is
4V/μs maximum. If the commutating dv/dt rating of the TRIAC is exceeded, the TRIAC could latch on. If the commutating dv/dt rating is exceeded in the 10…50 mA range, a resistor may be added AC
across the output and L2. The purpose of this resistor is to increase the total output current to 50 mA (I=V/R). At 50 mA and above, the module has a higher commutating dv/dt rating. When adding a
resistor for the output to L2, be sure it is rated for the power that it will dissipate (P=(V**2)/R). If the commutating dv/dt rating is exceeded in the 50…500 mA range, the L1 AC waveform could be at
fault. Be sure the waveform is a good sinusoid, void of any anomalies such as distorted or flattened sections.
I understand roughly what it is saying, that the rate of voltage change can not be at any higher than the values given, however I'm having difficulty getting this info from any of my output devices.
An example of one of the outputs is AB 100-C contactors.
http://literature.rockwellautomation.com/idc/groups/literature/documents/td/100-td013_-en-p.pdf
Any help or experiences regarding this would be appreciated.
Thanks in advance, Will.
