Table 16 - Modes Of Operation - York eco2 050 Installation Operation & Maintenance

TABLE 16 – CV (CONSTANT VOLUME) MODES OF OPERATION
Control Heating
Occupied
Thermostat Controller Occupied input is
ON (energized by 'stat occ.
output, or by an external
com mand). 'stat uses its
programmed occupied htg.
Setpoint. Supply fan con-
trolled by 'stat's G output.
Economizer damper at
programmed min. position.
'stat W1, W2 outputs control
heating stages 1and 2.
If hydronic heat or modulat-
ing gas heat, 'stat W1,W2
outputs select programmed
"Hydro heat 1
stage Setpoints
Space Sensor Controller Occupied input
is ON (energized by an
external command). Space
temperature is controlled
to a programmed oc-
cupied htg. setpoint. For
supply fan, setting of the
parameter "Fan ON mode
with the Sensor Option"
determines if the supply
fan is ON continuously,
or is in "Auto" mode (i.e.
goes off when space is
satisfi ed). Economizer
damper at programmed
min. position Heating is
controlled by a PI algorithm
that controls staging of heat
stages and modulates
duty cycle of the highest
numbered running heating
stage. If hydronic heat or
modulating gas heat, space
control algorithm selects
programmed "Hydro Heat
st
1 Stage SAT Setpoint" and
"Hydronic Heat 2
SAT Setpoint"
YORK INTERNATIONAL
Unoccupied
Controller Occupied input
is OFF (deenergized by
'stat occ. output, or by an
external command).
Economizer damper is at
0% Control is same as oc-
cupied heating, except 'stat
uses its programmed unoc-
cupied heating setpoint.
st and 2 nd
Controller Oc cu pied input
is OFF (deenergized by
an external command).
Economizer damper is at
0% Supply fan is in "Auto"
mode (i.e. goes off when
space is satisfi ed). Control
is same as occupied heat-
ing, except space tem-
perature is controlled to a
programmed unoccupied
heating setpoint.
nd Stage
FORM 100.50-NOM1 (604)
Cooling
Occupied Unoccupied
Controller Occupied input is Controller Occupied input
ON (energized by 'stat occ. is OFF (deenergized by
output, or by an external 'stat occ. output, or by an
command). 'stat uses its ex ter nal command).
programmed occupied clg. Economizer damper is at
setpoint. Supply fan con- 0% (damper may modulate
trolled by 'stat's G output open if free cooling is being
Economizer damper at used). Control is same as
programmed min. position, occupied cooling, except
may modulate open if free 'stat uses its pro grammed
cooling is being used. unoccupied cooling set-
Mechanical cooling mode: point.
'stat Y1, Y2 outputs control
stage 1 and 2 compressors
Economizer mode:
'stat Y1, Y2 outputs select
High and Low programmed
Economizer SAT setpoints,
SAT controlled by econo-
mizer control algorithm.
Controller Occupied input Controller Occupied input
is ON (energized by an is OFF (deenergized by an
external command). Space external command).
temperature is controlled Economizer damper is at
to a programmed occupied 0% (damper may modulate
clg. setpoint. open if free cooling is being
For supply fan, setting of used).
the parameter "Fan ON Supply fan is in "Auto"
mode with the Sensor mode (i.e. goes off when
Option" determines if the space is satisfi ed).
supply fan is ON continu- Control is same as oc-
ously, or is in "Auto" mode cupied cooling with a space
(i.e. goes off when space is sensor, except space
satisfi ed). temperature is con trolled to
Economizer damper at a programmed unoccupied
programmed min. position, clg. setpoint.
may modulate open if free
cooling is being used.
Mechanical cooling mode:
Cooling is controlled by a
PI algorithm that controls
compressor staging and
modulates duty cycle of the
highest num bered running
compressor.
Economizer mode:
Space control algorithm
selects High and Low pro-
grammed Economizer SAT
setpoints, SAT controlled
by economizer control
algorithm.
5
57