Perma Pure Modular Board - Manual (Page 9)

External Switch 1 will force the relays off even when there is no water present
and the impinger temperature is below ‘Ready’. This can be used to keep the
sample pump from turning on as soon as the cooler is ready to allow for other
portions of the system to become ready for sampling.
External Switch 2 will reset the latched alarms. This switch is only active when
the Relay = Latch option is selected in set up.
1
St
Frozen
There are two dry contact inputs for each board labeled External Switches.
External Switch 1 will force the changeover of active impingers in the frozen
system. The switch is not active during the changeover period when both
impingers are cooling.
External Switch 2 has no associated function.
2
nd
Frozen
External Switches have no associated functions.
Dual Channel Cooler
There are two dry contact inputs for each board labeled External Switches.
External Switch 1 will select the channel to be displayed. This switch is only
active when the Display = Switch option is selected in set up. An open connection
between the terminals displays channel 1; a contact closure displays channel 2.
External Switch 2 has no associated function.
NJ Thermocouple Display
There are two dry contact inputs for each board labeled External Switches.
External Switch 1 will select the channel to be displayed. This switch is only
active when the Display = Switch option is selected in set up. An open connection
between the terminals displays channel 1; a contact closure displays channel 2.
External Switch 2 has no associated function.
Calibration
Overview
Each board must be calibrated before use. The calibration consist of several steps
including setting the Cold Junction temperature, calibrating the thermocouple
input for channel 1 and 2, and calibrating the voltage output 1 and 2.