I-Tec Economizer Sequence Of Operation; Heating Mode Operation; Ventilation Mode - Bard I30A1DA Installation Instructions Manual

I-TEC ECONOMIZER SEQUENCE OF
OPERATION
If Outdoor Temperature is Below Outdoor Thermostat
Setpoint
On call from CompleteStat
• "YO" thermostat signal powers vent blower motors
at Economizer Speed/Airflow (black – 525 CFM)
through NC contacts of Relay "R1" ("Dehum
Relay").
On call from CompleteStat
cooling:
• "YO" thermostat signal powers vent blower motors
at Economizer Speed/Airflow (black – 525 CFM)
through NC contacts of Relay "R1" ("Dehum
Relay").
• "Y1" thermostat signal powers "Y1" terminal on
unit low voltage terminal strip through NC contacts
of relay "R2" ("High Ambient Relay").
On call from CompleteStat
stage cooling:
• "YO" thermostat signal powers vent blower motors
at Economizer Speed/Airflow (black – 525 CFM)
through NC contacts of Relay "R1" ("Dehum
Relay").
• "Y1" thermostat signal powers "Y1" terminal on
unit low voltage terminal strip through NC contacts
of relay "R2" ("High Ambient Relay").
• "Y2" thermostat signal powers "Y2" terminal on
unit low voltage terminal strip through NC contacts
of relay "R2" ("High Ambient Relay").
If Outdoor Temperature is Above Outdoor Thermostat
Setpoint
On call from CompleteStat for first stage cooling:
• "YO" thermostat signal powers relay coil "R2".
"R2" relay then closes NO contact between "R"
and "Y1" at low voltage terminal strip engaging
stage 1 mechanical cooling. NC contacts of relay
"R2" that connects thermostat "Y1" to "Y1" on
low voltage terminal strip is opened to eliminate
feedback.
On call from CompleteStat
cooling:
• "YO" thermostat signal powers relay coil "R2". "R2"
relay then closes NO contact between "R" and
"Y1" at low voltage terminal strip engaging stage 1
mechanical cooling. NC contacts of relay "R2" that
connects thermostat "Y1" to "Y1" on low voltage
terminal strip is opened to eliminate feedback.
Manual 2100-597G
Page 40 of 68
for first stage cooling:
TM
for first and second stage
TM
for first, second and third
TM
for first and second stage
TM
• "Y1" thermostat signal powers relay coil "R3"
through now closed relay contacts "R2" closing
contacts between "R" and "Y2" at low voltage
terminal strip.
• "Y2" thermostat signal will do nothing, as NC
contacts of relay "R2" are now opened to eliminate
any feedback to thermostat.
Dehumidification Mode
On call from CompleteStat
• "D" thermostat signal powers relay coil "R1"
(Dehum. Relay). "R1" relay, then opens NC
contact between "YO" and outdoor thermostat.
 This will then negate any ECONOMIZER
SPEED SIGNAL from energizing the ventilation
package.
 "Y1" & "Y2" thermostat signals will pass
through NC contacts of Relay "R2" ("High
Ambient Relay") as relay coil "R2" will
be rendered inoperable by "R1" contacts
opening. Normal cooling calls can then still
apply to override Dehum. call.

HEATING MODE OPERATION

CompleteStat should never energize "YO" terminals
in conjunction with "B", so relay "R2" will never
energize, and neither will Economizer Ventilation
Speed.
"Y1" and "Y2" signals will pass through NC contacts of
relay "R2" contacts, and all heating operations will be
normal.

VENTILATION MODE

The call for ventilation will never be disrupted with this
control circuit. Anytime "A" signal from CompleteStat
is present, the "VENTILATION SPEED" of the vent
package will be energized. "A" Signal from thermostat
will also energize relay "R4" ("Blower Interlock Relay")
completing a circuit from "R" to "G" through the "NO"
contacts to ensure blower operations on the ventilation
call.
for dehumidification:
TM