NSBR211 blood bank fridge - does anyone know where on the controller to hook up a two-wire remote alarm on pre-2009 NSBR211 blood bank fridges? The remote monitor needs to see a NO contact that closes under a temperature or power fail alarm condition. The contacts I measure on the controller all read 20Mohms and from 9-14VAC, which puts a voltage back into the monitor node and blows it. I've tried paralleling a second power fail alarm relay off the original one, which worked a couple of times but now the controller won't even give a local alarm when a probe measures past a setpoint.
On the log chart there are two separate incidents of temperature increasing and decreasing over an 8 hr period. Starting at -40 rising to 0 and decreasing back to -40. The unit is a Jewett(now Thermo Scientific)BPL 13 freezer. Any help with this issue would be great.
