Set up - Intial Adjustment of Set Points
z
Enter program mode by pressing and releasing the PGM
button
z
Press the PGM button to advance to 'SP1' as shown in the
TEMPERATURE display window. This is the desired space
temperature set point. Ajust SP1 to the desired value using
the UP/DOWN buttons.
z
Press the PGM button once again to advance to 'SP2'. This
is the maximum allowable outside air temperature set
point. Ajust SP2 to the desired value using the UP/DOWN
buttons.
z
Press & Hold the PGM button to exit programming mode.
Operation - Adjusting Space Temperature
z
Press and hold the PGM button.
z
While holding the PGM button depressed, use the UP/DOWN
buttons to adjust the desired space temperature (SP1) as
shown in the SETPOINT display window. Note that when
SP1 is adjusted in this manner, SP2 is automatically
adjusted as needed to maintain the offset specified during
intial adjustment.
Simplified Logic:
If (TP1 >= SP1+dif)
// space temperature higher than desired
{
if (TP2<=SP2-dif)
Close_Relay1_Contacts
// ventilate
else
Close_ Relay2_contacts
// outside air too hot, engage
mechanical cooling
}
else Open_Relays_1&2_contacts
// set point satisfied, no cooling
required
Note: Operation of Relay 1 and Relay 2 are mutually
exclusive. If relay 1 is engaged, relay 2 will be disengaged
and vice-versa.