Temperature Compensated Start - Carrier Weathermaster 48P030-100 Controls, Start-Up, Operation, Service, And Troubleshooting

Airflow
2a'
2'
3a'
CIRCUIT B
3-WAY VALVE
CHECK VALVE
4'
3'
EXPANSION
DEVICE

Temperature Compensated Start

This logic is used when the unit is in the unoccupied state. The
control will calculate early Start Bias time based on Space Tem-
perature deviation from the occupied cooling and heating set
points. This will allow the control to start the unit so that the space
is at conditioned levels when the occupied period starts. This is re-
quired for ASHRAE 90.1-2016 compliance. A space sensor is re-
quired for non-linkage applications.
SETTING UP THE SYSTEM
The settings for temperature compensated start can be found in the
local display under Configuration
ITEM EXPANSION
TCS.C Temp.Cmp.Strt.Cool Factr
TCS.H Temp.Cmp.Strt.Heat Factr
EVAPORATOR
CCT
Evaporator Discharge Temperature
In Subcool or Reheat Mode, compressor staging
and increased subcooling drives evaporator
discharge temperature down to meet higher latent
loads
D.C.SP COOL
Fig. 14 — Humidi-MiZer System Control
BYPASS
MODULATING
VALVE
CONDENSER
MODULATING
VALVE
CONDENSER
OUTDOOR AIR
COMPRESSOR
REHEAT HX
EVAPORATOR
5'
INDOOR AIR
Fig. 15 — Humidi-MiZer System Diagram

UNIT.
RANGE UNITS CCN POINT
0 to 60 min TCSTCOOL
0 to 60 min TCSTHEAT
HUMIDI-MIZER ADAPTIVE
DEHUMIDIFICATION
SYSTEM COIL
Supply Air Temperature Control
Innovative algorithm to control supply air temperature
modulates flow bypass to meet desired supply air setpoint -
no overcooling or overheating of the space.
Subcooling Mode: Meet Cooling Mode Supply Air Setpoint
Reheat Mode: Meet Return Air Offset or Reheat Setpoint (configurable)
RAT-D.V.RA or
D.V.HT
1'
4
3
EXPANSION
TCST-Cool Factor (TCS.C)
This is the factor for the start time bias equation for cooling.
TCST-Heat Factor (TCS.H)
This is the factor for the start time bias equation for heating.
NOTE: Temperature compensated start is disabled when these
factors are set to 0.
TEMPERATURE COMPENSATED START LOGIC
The following conditions must be met for the algorithm to run:
• Unit is in unoccupied state.
• Next occupied time is valid.
• Current time of day is valid.
• Valid space temperature reading is available (sensor or
DAV-Linkage).
96
SAT
or SASPHT
2
CONDENSER
OUTDOOR AIR
COMPRESSOR
CIRCUIT A
EVAPORATOR
5
1