Carrier 48HG016, Управление, эксплуатация и устранение неисправностей

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If the user has selected Adaptive (see Cooling section) for
thermostat mode, the algorithm will follow the configurable
delays for adding and removing stages. When adding addition-
al heat stages, the delay is measured from when the last stage
was added (H.INC). When removing stages, the delay is mea-
sured from when the last stage was removed (H.DEC). There-
fore, if W1 and W2 turn on simultaneously, the second stage
will turn on after a H.INC delay.
NOTE: If the mode is not Adaptive, then there are no delays
for adding and removing stages.
SPACE SENSOR CONTROL — During Space Sensor con-
trol, the electronic control uses information from the space
sensor to determine the number of heat stages. Once, the num-
ber of stages needed for heating is determined, either HTR.1 or
W1 and W2 outputs will be turned on. See Space Sensor
Control section for 48HG units.
NOTE: The jumper wire in the installer's packer must be con-
nected between R and W1 when using a T55, T56, or T58
device. See Fig. 1 and 2.
Cooling —
If the outdoor temperature is less than the Com-
pressor Lockout Temperature (MC.LO), then compressors will
not operate.
THERMOSTAT CONTROL — There are three types of ther-
mostat control as defined by thermostat control type (T.CTL):
0 is referred to as Adaptive control, 1 is referred to as 1-stage
Y1, and 2 as 2-stage Y1. The preferred method of control is
Adaptive.
For both 1-stage Y1 and 2-stage Y1 control methods, the
adaptive control method is used whenever the economizer can
provide cooling, regardless of the selected control method.
This will ensure proper time delays and SAT control when the
economizer is cooling. If the economizer cannot provide cool-
ing, then the 1-stage Y1 and 2-stage Y1 control methods follow
the thermostat inputs directly.
On two-compressor units (size 014 and 028 units), the
1-stage Y1 and 2-stage Y1 control methods are identical and
the compressor outputs follow the thermostat inputs directly,
obeying the compressor minimum on-time (MRT.C) and
minimum off-time (MOT.C) (equal to 3 and 5 minutes,
respectively).
For 3-compressor units (size 016 to 024 units), Y1 will turn
on one stage when configured for 1-stage Y1, and two stages
when configured for 2-stage Y1. When Y2 is On, all three
stages will operate. The compressor must follow the minimum
on- and off-time requirements. If multiple compressor are
requested on or off simultaneously, the compressors will be
staged at a 5-second interval.
In Adaptive mode, thermostat cooling begins when the Y1
input is energized. If the economizer is available for cooling,
the economizer will try to provide cooling as discussed in the
Economizer section. If the economizer is not available for cool-
ing or the economizer has been at 100% for 5 minutes, com-
pressor staging will begin when Y1 is energized.
For size 014 and 028 units, the compressor stages will fol-
low the Y1 and Y2 inputs directly with a configurable delay
when adding stages (C.INC) and when removing stages
(C.DEC). Therefore, if Y1 and Y2 turn on simultaneously, the
second stage will turn on after a C.INC delay. In Adaptive
mode, a stage of compression cannot be turned on if the Supply
Air Temperature (SAT) is less than Minimum Supply Air
Temperature Upper Level (MIN.H). In addition, a stage of
compression will be removed if SAT is less than the Minimum
Supply Air Temperature Lower Level (MIN.L). If MIN.H and
MIN.L are configured so that they are close together, the last
stage of compressor might cycle rapidly, slowed only by its
minimum on- and off-time requirements.
For size 016 to 024 units, the algorithm must decide how to
map a two-stage thermostat to three stages of compression. The
staging algorithm uses information from Y1, Y2, and the
supply-air temperature to determine the number of stages. If
Y1 = OFF, then no compressors will operate unless they are
being forced to run in order to status their minimum on-time. If
Y1 = ON, then either 1 or 2 stages will operate. Finally, if
Y2 = ON, then after the C.INC delay times, the maximum
number of stages will operate. When only Y1 is ON, the unit
will decide to operate 1 or 2 stages of compression using the
following logic. When Y1 turns ON, the first stage of compres-
sor will turn on immediately. The algorithms begin to count the
number of seconds since the last change in the number of
compressors (in this case, from 0 to 1). After the compressor
settling time (SAT.T) is reached, a reference value for SAT is
stored. If, while operating with only one compressor on, the
return temperature begins to rise, and therefore the SAT
temperature rises also, the second compressor will be added
when SAT is greater the SAT reference plus SAT positive
demand (SA.PD). After the second compressor has been add-
ed, another SAT reference value will be taken. The second
stage will be turned off when SAT is less than SAT reference
plus SAT negative demand (SA.ND). If at anytime Y2 is turned
ON, then the algorithm would immediately try to reach 3 stag-
es following the C.INC requirement. If Y1 turns OFF, then all
the compressors will turn off after their minimum on-time has
been met.
SPACE SENSOR CONTROL — To operate the unit in
Space Sensor mode, Unit Control Type must be set to Space
Sensor (3) and a wire must be added between R and W1 on
TB4. See Fig. 1 or 2.
While in space sensor control mode, the unit tries to main-
tain the Space Temperature (SPT) at one of 4 different set
points: the Occupied Cool Set Point (OCSP), the Unoccupied
Cool Set Point (UCSP), the Occupied Heat Set Point (OHSP),
or the Unoccupied Heat Set Point (UHSP). The building’s
occupancy is affected by a number of different factors. See
Occupancy Determination section on page 26. When the build-
ing is occupied, the occupied set points are active. When the
building is unoccupied, the unoccupied set points are active.
Because Space Sensor mode is an “Auto” mode, the control
will switch between cooling and heating to maintain tempera-
ture. However, to minimize unnecessary cool to heat and heat
to cool changes, there is a 10-minute delay after the last stage
turns off before the control will switch modes.
To maintain temperature while cooling, the unit will turn on
compressors as needed when the economizer is either unavail-
able or not providing enough cooling. Information from the
space sensor and the supply temperature sensor is used to
determine the number of necessary stages. The minimum
on-time for each compressor is 3 minutes (MRT.C). The mini-
mum off-time is 5 minutes (MOT.C).
Because the unit contains 3 compressors, each with its own
circuit, there are 3 stages of cooling (the economizer is not
considered a stage of cooling even though it can provide cool-
ing in certain situations). In general, the minimum time
between increasing stages is a configurable delay (C.INC). The
minimum time between decreasing stages is a configurable
delay (C.DEC).
The unit will request a stage of cooling whenever the Cool
Demand (SPT – set point) is greater than the SPT Cool De-
mand Positive Level (CL.PD) plus the change in Cool Demand
times the Cool Thermal Lag (C.LAG).