102777-YIM-E-0206
82
Unitary Products Group
Sensor with Space Setpoint Adjust
-
This Sensor has
a slider potentiometer on it that represents (as a default) +/-
3
°
F adjustment to the Space Setpoint. The Space Setpoint
Offset option. If the unit appears to be controlling at a higher
or lower temperature than the setpoint, check the Space Set-
point Adjust slider.
SUPPLY FAN CONTROL WHEN USING A ZONE SENSOR
In the Occupied mode, setting of the parameter "Fan ON
mode with the Sensor Option" will determine if the Supply
Fan is ON continuously, or is in "Auto" mode (i.e. cycles with
the heating/ cooling cycles). In Unoccupied mode, the fan is
always in the Auto mode.
SUPPLY FAN OFF DELAY
Uses minimum off time.
CONTROL OF COMPRESSORS WHEN USING A ZONE
SENSOR
A Minimum run time of one to ten minutes [default = three]
applies to all compressors. The minimum run time is neces-
sary to ensure that the oil in the refrigerant circuit circulates
back to the compressor.
The Anti Short Cycle delay of five minutes OFF applies any
time compressor operation is terminated. Compressors are
turned ON and OFF individually during CV operation with a
zone sensor, where the cooling control algorithm is imple-
mented in the controller (rather than in a thermostat).
The stage groups are applicable only for control of compres-
sors with external signals, such as from a thermostat.
There is a minimum 30 second delay between compressors
when bringing on multiple compressors.
HEATING OPERATION WITH THE SENSOR OPTION
The space temperature is controlled to a programmed Unoc-
cupied Heating Setpoint, or to a programmed Occupied Heat-
ing Setpoint, as determined by the internal schedule and the
state of the Occupied Input (if this input is ON during a sched-
uled unoccupied time, the unit goes to Occupied Override
mode).
The control will use as many as three stages of heat, depend-
ing on what heat option is are installed.
A zone heating demand of -1.5
°
F will generate a request for
first stage heat.
A zone heating demand of -2.0
°
F will generate a request for
second stage heat.
A zone heating demand of -2.5
°
F will generate a request for
third stage heat. There is a three minute minimum off delay
and a thirty second delay between stages.
When the zone temperature is -0.1
°
F, or less below the zone
setpoint for at least 1 minute, the transition to a satisfied state
occurs, the heating stops and the supply fan either continues
running, or is turned off after SAT drops below 100
°
F. The
supply fan control in the satisfied state and in the occupied
mode is determined by setting of the programmable parame-
ter "Fan ON Mode with the Sensor Option". In the unoccupied
mode, the fan is always turned off when the zone is satisfied.
During heating, the SAT control to the selected SAT setpoint
is performed using a PI algorithm. Two minute Minimum Run
Time and Anti Short Cycle delays applies to all heat stages.
There is also a delay of at least one minute between turning
on heating stages.
COOLING OPERATION WITH THE SENSOR OPTION
The control will operate as a two-stage unit.
On two compressor units, compressor one is first stage and
compressor two is second stage.
On three compressor units, compressors one and two are
first stage and compressor three is second stage.
On four compressor units, compressors one and two are first
stage and compressors three and four are second stage.
The control uses a minimum 30-second compressor delay
between compressors when bringing on a stage with multiple
compressors.
A zone cooling demand 1.5
°
makes a call for first stage cool-
ing.
A zone cooling demand 2.0
°
makes a call for second stage
cooling.
If the unit has a demand greater than 1.5
°
but less than 2.0
°
,
the control will turn on the first compressor of stage one and
load a 5-minute timer. If after 5 minutes the Space tempera-
ture is not moving toward the Setpoint, the control will turn on
the second compressor of stage one, if available, and wait 5
minutes. The control will continue operating first stage until
the Space temperature reaches the Setpoint and then it will
turn off the stage one compressor. If after 5 minutes the
Space temperature is not moving toward the Setpoint, the
control will turn on the first compressor of stage two and wait
5 minutes. The control will continue to turn on compressors
using the 5-minute trending timer until the Space Tempera-
ture begins to move toward the Setpoint. The control will turn
off all the second stage compressors with a 30-second delay
between them when the demand reaches .5
°
F. The control
will continue operating first stage until the Space temperature
reaches the Setpoint and then it will turn off the entire stage
one compressor.
If the unit starts with a demand greater than 2.0
°
F, the control
will stage up first stage and wait 5 minutes. The control will
Summary of Contents for MILLENNIUM Y22
Page 47: ...102777 YIM E 0206 Unitary Products Group 47 FIGURE 20 ALTITUDE TEMPERATURE CONVERSION FACTOR ...
Page 50: ...102777 YIM E 0206 50 Unitary Products Group FIGURE 21 FAN PERFORMANCE 25 TON ...
Page 53: ...102777 YIM E 0206 Unitary Products Group 53 FIGURE 22 FAN PERFORMANCE 30 TON ...
Page 56: ...102777 YIM E 0206 56 Unitary Products Group FIGURE 23 FAN PERFORMANCE 40 TON ...
Page 126: ...102777 YIM E 0206 126 Unitary Products Group FIGURE 52 TYPICAL CONTROL WIRING ...
Page 127: ...102777 YIM E 0206 Unitary Products Group 127 FIGURE 53 LEGEND ...
Page 128: ...102777 YIM E 0206 128 Unitary Products Group FIGURE 54 TYPICAL 25 TON POWER WIRING ...
Page 129: ...102777 YIM E 0206 Unitary Products Group 129 FIGURE 55 TYPICAL 30 40 TON POWER WIRING ...
Page 130: ...102777 YIM E 0206 130 Unitary Products Group FIGURE 56 TYPICAL GAS HEAT WIRING ...
Page 134: ...102777 YIM E 0206 134 Unitary Products Group FIGURE 58 25 TON CHARGING CURVE ...
Page 139: ...102777 YIM E 0206 Unitary Products Group 139 ...
