
102777-YIM-E-0206
84
Unitary Products Group
The supply fan operates at 100% during heating. Depending
on the control setting, the fan will cycle On/Off with the W1
output, or will remain On. On startup, the fan speed is ramped
up, or the inlet vanes ramped open (a "soft start").
During occupied heating, the economizer damper remains at
minimum position and all VAV boxes are fully open - box heat
relays are energized from Heat output of the controller. If
Hydronic heat option is used, the Heat output of the controller
is also actuated during heating, the SAT is controlled to the
2nd stage hydronic heat setpoint.
UNOCCUPIED HEATING WITH A THERMOSTAT
This operation is identical to the Occupied heating, except
the unit mode is in Unoccupied mode from the internal control
Occupied/Unoccupied table. The economizer damper
remains fully closed in the unoccupied mode.
OCCUPIED COOLING WITH A THERMOSTAT
In this mode, the control uses a thermostat for cooling and
fan operation. The thermostat's occupied cooling setpoint
should be set below the zone thermostat's lowest adjustable
cooling setpoint, to prevent a possibility of cooling turned off
while other zone(s) in the system still have a cooling demand.
UNOCCUPIED COOLING WITH A THERMOSTAT
This operation is identical to the Occupied cooling, except
when operating in the unoccupied mode the control is pro-
grammed to control to its unoccupied cooling setpoint and the
economizer damper min. position is set to 0%, however the
damper may modulate open if outdoor air can be used for
free cooling (economizer operation).
OCCUPIED HEATING WITH A SPACE SENSOR
The Space Sensor is placed in a selected, representative
zone of the VAV system, in addition to the zone thermostat, or
sensor used to control the zone's VAV box. The heating con-
trol algorithm is enabled whenever the zone temperature
drops 2
°
F or more below a programmed "VAV SAT Reset Set-
point ", and disabled whenever the zone temperature is 1.5
°
F,
or less below a programmed “VAV SAT Reset Setpoint". The
"VAV SAT Reset Setpoint" would typically be set at, or below
the lowest zone temperature setpoint selectable on the zone
thermostat.
The supply fan is controlled to 100% during occupied heating
and cycles OFF when the heating control algorithm is satis-
fied if there is no other call for the fan. On startup, the fan
speed is ramped up, or the inlet vanes ramped open (a "soft
start").
When a call for heating (W1 or W2=ON) occurs, the econo-
mizer damper remains at its programmed minimum position
and all VAV boxes go fully open - box heat relays are ener-
gized from Heat output of the controller.
If Hydronic heat option is used, the Heat output of the control-
ler is also actuated during heating and the SAT is controlled
to the 2
nd
stage hydronic heat setpoint.
UNOCCUPIED HEATING WITH A SPACE SENSOR
When this mode is enabled and the unit enters the unoccu-
pied mode, the unit will control heating by comparing the
zone temperature to a programmed "Unoccupied Heating
Setpoint". The Space Sensor should be placed in a selected,
representative zone of the VAV system, in addition to the
zone thermostat, or sensor used to control the zone's VAV
box.
Full heating (all heating stages ON) occurs when the Space
Sensor algorithm requests heating, no heating (all heating
stages OFF) when the Space Sensor algorithm is satisfied
(note that in this case, the control will use all available heat-
ing stages, regardless of setting of the programmable param-
eter "Heat Stages").
The supply fan is controlled to 100% during unoccupied heat-
ing and cycles OFF when the Space Sensor control algorithm
is satisfied if there is no other call for the fan. On startup, the
fan speed is ramped up, or the inlet vanes ramped open (a
"soft start").
During unoccupied heating, the economizer damper is fully
closed and all VAV boxes go fully open - box heat relays are
energized from Heat output of the controller.
OCCUPIED COOLING WITH A SPACE SENSOR
This mode is entered when the control sees a Space Sensor
signal and enters the "occupied" mode. The Space Sensor
requests cooling (to a programmed High, or Low SAT set-
point) whenever the zone temperature increases by a speci-
fied amount above a programmed "VAV SAT Rest Setpoint".
The Space Sensor should be placed in a selected, represen-
tative zone of the VAV system, in addition to the zone thermo-
stat, or sensor used to control the zone's VAV box.
The "VAV SAT Reset Setpoint" would typically be set at, or
below the lowest zone temperature setpoint selectable on the
zone thermostat, in order to prevent a possibility of insuffi-
cient cooling while other zone(s) in the system still have a
high cooling demand.
The supply fan, economizer, VAV boxes operate within their
normal control rules.
UNOCCUPIED COOLING WITH A SPACE SENSOR
In this mode, the Space Sensor requests cooling based on
comparing the zone temperature to a programmed "Unoccu-
pied Cooling Setpoint". When the Space Sensor control algo-
rithm requests cooling, the unit runs cooling controlled to a
programmed High SAT setpoint ("VAV Upper Cooling SAT
Setpoint"), or to a programmed Low SAT Setpoint ("VAV
Upper Cooling SAT Setpoint"), as determined by comparison
Содержание MILLENNIUM Y22
Страница 47: ...102777 YIM E 0206 Unitary Products Group 47 FIGURE 20 ALTITUDE TEMPERATURE CONVERSION FACTOR ...
Страница 50: ...102777 YIM E 0206 50 Unitary Products Group FIGURE 21 FAN PERFORMANCE 25 TON ...
Страница 53: ...102777 YIM E 0206 Unitary Products Group 53 FIGURE 22 FAN PERFORMANCE 30 TON ...
Страница 56: ...102777 YIM E 0206 56 Unitary Products Group FIGURE 23 FAN PERFORMANCE 40 TON ...
Страница 62: ...102777 YIM E 0206 62 Unitary Products Group FIGURE 25 POWER EXHAUST TWO FORWARD CURVED FANS 30 40 TONS ...
Страница 126: ...102777 YIM E 0206 126 Unitary Products Group FIGURE 52 TYPICAL CONTROL WIRING ...
Страница 127: ...102777 YIM E 0206 Unitary Products Group 127 FIGURE 53 LEGEND ...
Страница 128: ...102777 YIM E 0206 128 Unitary Products Group FIGURE 54 TYPICAL 25 TON POWER WIRING ...
Страница 129: ...102777 YIM E 0206 Unitary Products Group 129 FIGURE 55 TYPICAL 30 40 TON POWER WIRING ...
Страница 130: ...102777 YIM E 0206 130 Unitary Products Group FIGURE 56 TYPICAL GAS HEAT WIRING ...
Страница 134: ...102777 YIM E 0206 134 Unitary Products Group FIGURE 58 25 TON CHARGING CURVE ...
Страница 138: ...102777 YIM E 0206 138 Unitary Products Group FIGURE 62 PRESSURE DROP DRY EVAPORATOR COIL VS SUPPLY AIR CFM 30 40 TON ...
Страница 139: ...102777 YIM E 0206 Unitary Products Group 139 ...