speters33w
Member
Nubee question on latching and unlatching relays
I have a customer with a Data center configured like below:
What I am trying to do is:
If Generator A doesn't start (On Battery over 30 Seconds AND Bypass available)
Send a retransfer inhibit to ATS B and latch output.
Wait, then check for On Battery over 30 Seconds AND Bypass available
Command UPS to bypass and latch output.
After Utility A is restored,
Remove UPS to bypass command (latched)
Wait
Check Utility A is available
Command UPS to normal (do not latch)
Check UPS is on normal
Remove ATS retransfer inhibit.
I know how to do this with a box full of relays and timers, but...
I decided to "get with the program" and see if I could use a PLC.
Seemed pretty simple until I tried to program it and simulate.
I came up with some hokey stuff like the circuit below that will probably NOT work, this is just the "tranfer UPS to bypass" chunk:
Does anyone have a sample circuit that does something similar to this I can look at?
ALSO... the outputs need to be isolated dry contact closure. What are they in PLCeze?
I looked at http://www.plctalk.net/qanda/showthread.php?t=16832 but I'm not sure I have an answer.
I have a customer with a Data center configured like below:
What I am trying to do is:
If Generator A doesn't start (On Battery over 30 Seconds AND Bypass available)
Send a retransfer inhibit to ATS B and latch output.
Wait, then check for On Battery over 30 Seconds AND Bypass available
Command UPS to bypass and latch output.
After Utility A is restored,
Remove UPS to bypass command (latched)
Wait
Check Utility A is available
Command UPS to normal (do not latch)
Check UPS is on normal
Remove ATS retransfer inhibit.
I know how to do this with a box full of relays and timers, but...
I decided to "get with the program" and see if I could use a PLC.
Seemed pretty simple until I tried to program it and simulate.
I came up with some hokey stuff like the circuit below that will probably NOT work, this is just the "tranfer UPS to bypass" chunk:
Does anyone have a sample circuit that does something similar to this I can look at?
ALSO... the outputs need to be isolated dry contact closure. What are they in PLCeze?
I looked at http://www.plctalk.net/qanda/showthread.php?t=16832 but I'm not sure I have an answer.
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