102777-YIM-E-0206
92
Unitary Products Group
de-energized when Supply fan is off or when the EAD open-
ing is less than the programmed Exhaust Damper Position for
Exhaust Fan to turn OFF, or 10% open, whichever is greater.
The minimum run time is 10 seconds and minimum off time is
60 seconds. (Non-adjustable). Default Setpoint settings are
for the EF to turn ON at Exhaust Air Damper 80% open and
turn OFF at Exhaust Air Damper 20% open. The Building
Pressure Setpoint default is 0.100" w.g.
PROPORTIONAL CONTROL WITH VFD FAN
This is similar to the proportional EAD option, except that the
damper signal is used to control motor speed using a variable
frequency drive.
TWO-POSITION CONTROL (POWER EXHAUST WITH
BAROMETRIC RELIEF, CONTROLLED FROM BUILDING
STATIC PRESSURE)
In this mode the Power Exhaust, Economizer and Building
Pressure Sensor Enable options must be ON. The Exhaust
Fan (EF) is controlled with a relay output of the controller. The
EF relay is energized whenever Supply fan is running and
building static pressure is above a programmed Building Pres-
sure Se 0.015 “ w.g. (3.7 Pa). The EF relay is de-ener-
gized when supply fan is off, or when building static pressure is
less than a programmed Building Pressure Setpoint - 0.015”
w.g. (3.7 Pa). The minimum run time is 10 seconds and mini-
mum off time 60 seconds (Non-adjustable). With this type of
control, the Power Exhaust fan cycle, as its operation directly
influences the building static pressure that controls it. The
cycling rate is limited by these minimum ON and OFF time set-
tings. The Building Pressure Setpoint default is 0.100" w.g.
ERV
During operation, the ERV [Energy Recovery Ventilation]
exhausts return air from the building, but it is not a 'power
exhaust'; the system is NOT controlled by building pressure.
If building pressure control is required, it must be done by
other means - standalone power exhaust, or power exhaust
in another unit serving the same space.
The ERV forces high volume fresh air exchange, but captures
the heat energy of the outgoing air and transfers it to the
incoming stream. ERV blower operation is NOT modulated to
a pressure setting; there is no building pressure transducer in
the system. The unit's supply fan pulls air through the inlet
side of the ERV wheel.
Ducting and demand will vary from one installation to another.
Adjusting the unit to achieve fresh air requirements and
'exhaust-neutral' air flow must be done by the installer, using
the manual dampers in the unit.
If the unit is variable air volume, the ERV exhaust motors will
be controlled by a variable frequency drive in the Millennium,
using the same signal voltage that modulates supply air,
either by inlet guide vane or variable frequency drive. This is
done to keep supply and exhaust air flow in balance.
The exhaust blowers in the ERV use the power and control
hardware that otherwise would run the power exhaust. The
EXH output from the Simplicity runs the ERV motors; if the
unit is VAV, the EXD+/- terminals provide the ERV variable
frequency drive speed signal.
Where a unit has both ERV and an economizer, the ERV will
stop wheel rotation when the economizer dampers open far
enough to trigger the user-settable switch in the damper actu-
ator. If free cooling is available, the heat exchange wheel
does not need to rotate; the wheel will cycle on schedule to
keep the air passages blown clean.
Also refer to the ERV Installation Instructions packaged with
the ERV.
SCHEDULING OPERATION
The Millennium Simplicity refers to its clock and internal cal-
endar.
COMPRESSOR STATUS MONITORING
Compressor status is monitored using three separate 24 VAC
circuits.
Monitoring: low pressure, high pressure, and compressor
modules.
The corresponding compressor status is monitored. If any of
the three safeties is in error, the trip is noted in the alarm his-
tory and the next available compressor will be used if
needed.
The Low Refrigerant Pressure Switch is Normally Open,
pressure closed. When the compressor is off and refrigerant
pressure equalized, the switch under normal conditions is
expected to be closed. However, in cold ambient operation, it
may stay open and close only after the compressor starts up.
If an error is detected for a compressor, that compressor’s
output is turned off (note that the controller executes the
application code once every 32ms, with a 30 second startup
delay and 5 second minimum error time on low pressure. The
control then declares a "Compressor Locked Out on [ ] Trip"
alarm. The alarm is written to the Error History Buffer.
NOTE:
The compressor lockout works as an override of the
output of the staging algorithm for cooling control.
For example, the cooling control may ask for com-
pressor #2 that is locked out, and as this request
does not generate additional cooling, will ask for the
next compressor, #3, to satisfy the cooling demand.
If, after 10 minutes, the requested compressor #2
does start up, the cooling output now may be
exceeding demand, and the control will turn off
compressor #3, etc.
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 ...
