SUPER-Selector
‘
PT Control
Page 12
Backup Considerations
While there are differing backup devices and philosophies, there is one indisputable
fact. This control is made from mechanical and electrical devices that have a finite
lifetime. The question is not "if", but rather "when", will this control stop functioning
correctly. If inadequate measures are taken to deal with this fact, poultry and livestock
may die as a result. IT IS ABSOLUTELY MANDATORY THAT A REASONABLE
LEVEL OF SAFETY DEVICES AND ALARMS BE INSTALLED. The alarm output
of the SUPER-Selector PT can be a part of these, but should never be considered as the
total backup system. Obviously, if the SUPER-Selector PT alarm output is not
functional, it would be unable to send an appropriate signal to an alarm or other backup
device(s). The only possible useful output of a non-functioning SUPER-Selector PT is
the fused 230V pair of terminals. A blown fuse caused by a nearby lightning strike will
remove the presence of 230 volts from these two terminals even though power is still
available at the input to the control. A device must be connected to these two terminals
that is designed to detect the absence of 230VAC, and take appropriate action. On a
regular basis, all backup devices should be exercised and tested.
Backup Wiring
The two figures (below and on page 13) reflect possible ways of implementing backup
thermostats.
Case #1
One thermostat per output backed up is used in this application.