Space Temperature Sensor; Building Pressure Sensor; Duct Static Pressure Sensor; Iaq Sensor - York MILLENNIUM Y22 Installation Manual

SPACE TEMPERATURE SENSOR

CV operation with a zone sensor: When this sensor fails
the control will see if it has a RAT sensor. If it has a RAT sen-
sor, the control will use it as a backup and continue tempera-
ture control to the active space temperature setpoint. If there
is no RAT Sensor, the control will shut down all outputs. If the
detected sensor failure is a short circuit, the error can be
declared only if the short persists for several minutes, in order
to distinguish a sensor failure from a short caused by some-
body pushing on Unoccupied Override button.
VAV operation: If the space temperature sensor fails, the
control will continue normal function, only SAT reset from
space temperature will be disabled.

BUILDING PRESSURE SENSOR

If this sensor fails, the Power Exhaust control will default to
operate as a two position Power Exhaust. The Power
Exhaust Fan will be controlled as a fixed speed, ON/OFF
Power exhaust fan, controlled from position of the Econo-
mizer damper. If the unit is equipped with a Modulating
Exhaust Air Damper, this damper will be closed.

DUCT STATIC PRESSURE SENSOR

If this sensor fails, all outputs are turned off and the unit is
shut down.

IAQ SENSOR

If the IAQ sensor fails, Demand Ventilation mode is de-acti-
vated.

SYSTEM ERRORS

HEATING SAT FAILURE

In Heating mode and all stages of heating energized, the SAT
must drive above the Supply Air Alarm Setpoint for Heating
within ten minutes or this SAT failure error will be activated.
The error will be written to the Error History Buffer. In net-
worked application, the error flag will be readable by the net-
work.

COOLING SAT FAILURE

In Cooling mode and all stages of compression are ener-
gized, the SAT must drive below the Supply Air Alarm Set-
point for Cooling within ten minutes or this SAT failure error
will be activated. The error will be written to the Error History
Buffer. In networked application, the error flag will be read-
able by the network.

SUPPLY FAN FAILURE

The conditions under which this failure is declared, and the
follow-up actions of the control when this error occurs are
described in a paragraph on Air Proving Switch Operation
earlier in this document. The error will be written to the Error
96
History Buffer. In networked application, the error flag will be
readable by the network.

COMPRESSOR SAFETY CHAIN TRIP

The conditions under which this failure is declared, and the
follow-up actions of the control when this error occurs are
described in a paragraph on Compressor Status Monitoring
earlier in this document. The error will be written to the Error
History Buffer. In networked application, the error flag will be
readable by the network.

DIRTY FILTER ALARM

The conditions under which this failure is declared, and the
follow-up actions of the control when this error occurs are
described in a paragraph on Dirty Filter Switch (DFS) option
earlier in this document. The error will be written to the Error
History Buffer. In networked application, the error flag will be
readable by the network.

HIGH DUCT STATIC ALARM

The conditions under which this failure is declared, and the
follow-up actions of the control when this error occurs are
described in a paragraph on Duct Static High Limit Setpoint
option earlier in this document. The error will be written to the
Error History Buffer. In networked application, the error flag
will be readable by the network.

HOT WATER COIL FREEZE ALARM

The conditions under which this failure is declared, and the
follow-up actions of the control when this error occurs are
described in a paragraph on FSI (Hot Water Freeze Protec-
tion) option earlier in this document. The error will be written
to the Error History Buffer. In networked application, the error
flag will be readable by the network.

THE MILLENNIUM SIMPLICITY CONTROL

INTRODUCTION AND OVERVIEW

Welcome to the new Millennium Simplicity control, a digital
control system designed specifically for the Millennium 25 to
40 Ton single package rooftop unit. The Simplicity is composed
of 72 monitored and controlled input and output points. The
control logic of the Simplicity extends on the rules built in to the
Synthesys control, and provides character displays in addition
to LED flashes to display information to the technician.
The Simplicity digital control performs all of the control and
monitoring functions that were originally done by separate
discrete relays, controls, and interlocking hardware. This
reduces manufacturing, service, and maintenance costs. The
Simplicity digital controller includes sophisticated control of
the individual components of the HVAC cooling/heating unit,
and has built-in rules that protect those components and opti-
mize the control to its environment. The cooling and heating
102777-YIM-E-0206
Unitary Products Group