W6215, W7215, W7460 ECONOMIZER LOGIC MODULES
63-2544—3
6
Table 3. W6215, W7215, W7460 Economizer Purge,
Shutdown, and Air Change I/O Logic.
a
Purge present only on W6215A, W7215A, and W7460A.
Shutdown
One contact closure shuts down all systems. When terminals
SD and SD1 connect through relay contacts or a jumper:
1.
Outdoor damper drives fully closed.
2.
Exhaust fan turns off.
3.
Indoor fan turns off.
Air Change
When terminals AC and AC1 connect through relay contacts
or a jumper:
1.
Outdoor damper drives fully open.
2.
Exhaust fan turns on.
3.
Indoor fan turns on.
NOTE: With Purge, Shutdown, and Air Change de-
energized, Exhaust will be de-energized unless the
signal exceeds the exhaust fan setpoint; other logic
module functions remain unaltered.
SETTINGS AND ADJUSTMENTS
Potentiometers with screwdriver adjustment slots, located on
the device face, provide adjustments for several parameters
(see Fig. 5 for locations on device):
— ISI setpoint.
— OSI setpoint (W7215B and W7460B only).
— Minimum damper position.
— Maximum damper position.
— Enthalpy changeover.
— Exhaust setpoint (W6215A, W7215A and W7460A only).
Indoor Sensor Input Setpoint
The logic module modulates the outdoor damper to provide
ventilation based on the 2-10 Vdc ISI. With no cooling signal,
the ISI overrides the outdoor air damper when ventilation
requires outdoor air.
Outdoor Sensor Input Setpoint
(W7215B and W7460B
only
)
The OSI logic operates from a 2-10 Vdc sensor signal. The
operation of these logic modules is slightly different from the
other models, see Table 4.
Table 4. W7215B and W7460B OSI Operation.
a
Modulation based on signal from mixed air sensor.
b
With ISI signal greater than mixed air sensor signal:
Modulation, based on ISI signal, between minimum and
maximum positions.
c
With ISI signal less than mixed air sensor signal:
Modulation, based on mixed air sensor signal, between:
M7215B: Minimum and full open positions
M7460B: Minimum and maximum positions.
d
Modulation based on mixed air sensor signal;
Alarm
terminals
connect to energize warning light, audio alarm, or air cleaner.
Table 5. W6215, W7215, W7460 Economizer I/O Logic.
a
For single enthalpy control, the module compares outdoor enthalpy to the ABCD setpoint.
b
If both stages of cooling are off, the system is off and the damper is at:
• Minimum position if ISI is below setpoint.
• Modulating if ISI is above setpoint.
c
W6215, W7460: Modulation, based on the mixed air sensor signal, between minimum and maximum positions.
W7215: Modulation, based on the mixed air sensor signal, between minimum and full-open positions.
d
Modulation, based on the ISI, between minimum and maximum positions.
e
Modulation, based on the greater of ISI and mixed air sensor signals, between minimum and either maximum position (ISI) or
fully open (mixed air signal).
NOTE: Each sensor has it’s own setpoint for threshold and LED indication.
INPUTS
OUTPUTS
Purge
a
Shut-
down
Air
Change
Damper
Unit
Control
Indoor
Fan Exhaust
On
-
-
Fully Closed Off
Off
On
Off
On
-
Off
Off
On
Fully Open
On
On
OSI
ISI
Actuator
OSI LED
Alarm
Below set Below set Modulates
a
Off
Off
Above set Modulates
b
Modulates
c
Above set Below set Fully closed On
Off
Above set Modulates
d
On
On
INPUTS
OUTPUTS
ISI
Enthalpy
a
Y1
b
Y2
b
Damper
Compressor
Outdoor
Return
1
2
Below set
(ISI LED Off)
High (Free Cooling LED Off)
Low
On
On
Minimum position On
On
On
Off
On
Off
Low (Free Cooling LED On)
High
On
On
Modulating
c
On
Off
On
Off
Off
Off
Above set
(ISI LED On)
High (Free Cooling LED Off)
Low
On
On
Modulating
d
On
On
On
Off
On
Off
Low (Free Cooling LED On)
High
On
On
Modulating
e
On
Off
On
Off
Off
Off