Post by jblebouquin on Sept 16, 2019 12:43:10 GMT -5
Hi, We use the embedded alarms/relays of Lakeshore 331 (or 335) in order to hard-stop the cooling of our dewar when the temperature is dropping below a dangerous threshold (200K). But the relays remain in "normal" state when the Lakeshore is switched OFF (same if it dies I guess) which creates a possible point-of-failure. Is there a way to revers the logic, meaning to set the relays in "activated" mode when they are *inside* the alarm range ? Thanks.
Post by Lake Shore Ogi on Sept 17, 2019 12:37:56 GMT -5
Hello! Have you used both of the relay's "normally open (NO)" and "normally closed (NC)" terminals? Depending on how you have your configuration setup, you could setup the alarm such that in case of power outage or failure, the appropriate set of terminals handles your safety logic and does not need the relay to be energized. Can you please tell us what contacts (on the relays) you are using and under what conditions they need to be open and closed? Best Regards, Ogi K.