York J Series Manual page 70

Service
If a Supply Fan Fault occurs, the controller will require
a manual reset to clear the fault and allow the unit to
restart.
Air Switch Fault:
When the Supply Fan is shut OFF, if the Supply Fan
Status input is still present after a 5 minute shutdown
delay, the control will declare an Air Switch Fault.
An Air Switch Fault will not cause the
unit to shut down; however, the fault
will remain active until the air proving
switch indicates normal operation.
BI #12, Filter Status
The Filter Status input will be tied to a differential pres-
sure switch, which will be used to indicate if the filters
are dirty. The filter status will be indicated as:
• Filter dirty – Filter Status 24VAC input present.
• Filter clean – Filter Status 24VAC input not pres-
ent.
The control will declare a dirty filter fault after the
Filter Status input has been present for one min-
ute.
The Dirty Filter Fault will remain active as long as
the Filter Status input is present.
BI #13, Evaporator Freezestat Input
Not used on Millennium units.
BI #14, HW Freezestat Input
If the HW (hot water) Freezestat parameter is "ON"
(indicating that a HW Freezestat sensor is installed and
is to be used), the control will monitor this input. The
HW Freezestat input will be interpreted as follows:
• No freeze condition – HW Freezestat 24 VAC input
present.
• Freeze condition – HW Freezestat 24 VAC input
not present.
When the HW Freezestat input opens, the control will:
• Open the Hot Water valve to 100%.
• Close the OA damper(s) and open the RA damper
to 100%.
• HW Freezestat must close for 5 minutes before the
unit will resume normal operation.
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• If the HW Freezestat input is open for 10 minutes,
the control will declare a HW Freeze Fault, shut
down the unit, and maintain the heating value output
at 100%.
A HW Freeze Fault will remain active as long as the
(hot water) Freezestat input is open. The fault will clear
when the Freezestat input closes for 5 minutes.
HW (hot water) Thermostatic Switch Settings are:
- open @ 35° +4°/-2°.
- close @ 47° +4°/-2°.
Note: This is an adjustable switch set (35° to 45°) set
at the factory to 35°F.
BI #15, Cool-Heat Changeover Relay Status
The Cool-Heat Changeover Relay (COR) Status input
is used to verify that the relays that route the ON/OFF
commands from the controller to the heating and cool-
ing equipment are as commanded by the controller. To
verify that the changeover relays are as required for
heating or cooling, the control will:
• For cooling operation – verify that the Cool-Heat
COR Status 24VAC input is present.
• For heating operation – verify that the Cool-Heat
COR Status 24VAC input is not present.
The control will delay 5 seconds from the time
the Changeover Relay control output is switched
before looking at the COR input for the Cool-Heat
COR Status.
If the Cool-Heat COR Status input is not correct, a
COR Fault is declared. The unit is shutdown. The fault
is cleared through manual reset.
BI #16, VFD Bypass Input
This input will be used to signal to the control that
the VFD has been bypassed and the supply fan is now
running full. The control will interpret this input as
follows:
• VFD not bypassed (normal condition) – VFD By-
pass 24VAC input not present.
• VFD bypassed – VFD Bypass 24 VAC input present
(24VAC).
When VFD Bypass is present the control will:
• Shut own all heating and cooling stages.
• Shut down the Supply Fan if operating.
• Energize the VAV Heat Relay output to open all
VAV boxes.
FORM 100.50-NOM7 (808)
JOHNSON CONTROLS