York MILLENNIUM Y22 Installation Manual Download Page 107

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102777-YIM-E-0206

Unitary Products Group

107

SAT Control for Cooling - (ON) -

This tells the control if it is

going to do excessive SAT monitoring and tripping or not, for
Cooling. The SAT should be maintained in an acceptable
range in order to achieve reliable compressor operation. The
compressor trip limits are user adjustable between 40°F and
65°F in one degree increments. The default cooling trip limits
are 50°F for stages 2-4, and 45°F for stage 1. When the SAT
drops below the trip limit for each respective compressor, that
compressor is locked out and a 5 minute ASCD is initiated for
that compressor. If this option is enabled, remember to set
the compressor cooling limits for low limit trip.

Power Exhaust - (ON) -

This tells the control if it has the

Power Exhaust option installed.

Economizer Damper Position for Exhaust Fan to turn ON
(Non-Modulating PE Only) - (60%) -

This tells the control

the Economizer Damper position to turn on the Exhaust Fan.
This value is based on the 0%-100% output drive signal from
the controller to the economizer damper actuator.

Economizer Damper Position for Exhaust Fan to turn
OFF (Non-Modulating PE only) - (20%) -

This tells the con-

trol the Economizer Damper position to turn off the Exhaust
Fan. This value is based on the 0%-100% output drive signal
from the controller to the economizer damper actuator.

Modulating Exhaust - (OFF) -

This tells the control if the

Power Exhaust is Modulating or not. A modulating exhaust
will be equipped with a Building Pressure Sensor [BPS]. A
Non-Modulating exhaust will look to the economizer damper
position to energize the EXD output. If the sensor gets dis-
connected, or fails, an alarm is set. The alarm can be turned
off by correcting the sensor problem (or; by turning off this
option). The control is not in this case self-configuring. It will
not automatically use the Building Pressure Sensor if the
sensor is connected.

Exhaust VFD Installed - (OFF) -

If the unit has a VFD, the

EXD output will be enabled when the supply fan is ON.

Exhaust Damper Position For The Exhaust Fan To Turn
On (Modulating Only) - (80%) -

This tells the control the

Exhaust Damper position at which to turn on the Exhaust
Fan. This value is based on the 0%-100% output drive signal
from the controller to the damper actuator.

Exhaust Damper Position For Exhaust Fan To Turn Off
(Modulating Only) - (20%) -

This tells the control the

Exhaust Damper position to turn off the Exhaust Fan. This
value is based on the 0%-100% output drive signal from the
controller to the damper actuator.

Building Pressure Setpoint - (+0.100”WG) -

This is the

pressure setpoint the control will maintain when operating a
Power Exhaust. The Building Pressure Setpoint is adjustable
from -0.200”WG to +0.200”WG. The factory programmed
default is +0.100”WC. This setpoint is used when the exhaust
control is implemented as Proportional Control (with a Modu-

lating Exhaust Air Damper or VFD controlled from building
static pressure), or as a Two-position Control using building
static (Power Exhaust Fan controlled on-off from building
static pressure).

Economizer - (ON) -

This tells the control that there is an

Economizer Installed.

Economizer Min Position - (20%) -

This tells the control

what the minimum outdoor damper position will be for the
Occupied mode. Adjustable from 0-100%, the Economizer
Minimum Position default is 20%.

Economizer First Stage Setpoint - (55

F) -

This tells the

control what Supply Air Temperature to maintain for a call for
first stage of cooling. This is used only during Constant Vol-
ume cooling mode with Economizer operation. The setpoint
is set at 55°F with an adjustable range from 40°F to 65°F.

Economizer Second Stage Setpoint - (50

F) -

This tells the

control what Supply Air Temperature to maintain for a call for
second stage of cooling. This is used only during Constant
Volume cooling mode with Economizer operation. This set-
point is set at 50°F with a range from 40°F to 65°F.

Outside Air Humidity (OAH) Sensor Enable - (OFF) -

This

setting tells the control that it is expected to use Outside Air
Enthalpy (calculated from Outside Air Temperature and Out-
side Air Relative Humidity sensed values) to decide if Outside
Air can be used for cooling.

The control is self-configuring to the best available decision
strategy for free cooling availability. For example, if it detects
that OAT and OAH and RAT and RAH sensors are all con-
nected and reliable, will self-configure for Differential Enthalpy
operation. If one of the return air sensors should fail, the con-
trol will reconfigure for Outside Enthalpy operation, etc.

If the OAH Sensor Enable option is turned ON, it means that
the Outside Enthalpy Operation, or better decision strategy, is
expected (and supported by installed sensors). If the appro-
priate sensors are not installed, or one of them failed, a sen-
sor failure alarm is set. The alarm can be turned off by turning
off the OAH Sensor Enable option. Thus, the option setting is
used to reflect the desired operation and mainly to control
sensor failure alarms

The option setting can be viewed as specifying that (the self-
configured economizer decision strategy has to be at least
this, or better, otherwise an alarm is set). If the option is OFF,
the control still may self configure to Outside Enthalpy Opera-
tion, or even to Differential Enthalpy Operation (if all needed
sensors are available), but this option setting will allow also
the decision strategy based on only OAT (in case other sen-
sors fail, or are not installed) without setting an alarm.

Outside Air Enthalpy Setpoint - (27 BTU/LB) -

This tells the

control an outside air enthalpy limit. Below this limit, outside
air is available for cooling. See enthalpy chart. This parame-