Trane 824 Comfort Control, Руководство по установке

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Installation Guide
page 34 18-HD72D1-1
Feature Description
Duty Cycle
When the control is requesting less capacity than the system can deliver, the control will duty cycle
to meet the required demand. The length and frequency of each duty cycle is based on the cycle rate
and current load value.
Dehumidification
There are two requirements before dehumidification is enabled:
• Dehumidification must be enabled through the Installer Setup.
• The indoor relative humidity must be above the desired setpoint.
The system will take the following actions once this condition is met:
• The blower will reduce air flow proportional to the amount of RH error. The control evaluates the
percentage of humidity error and how long the error has existed to determine the amount of air
flow reduction, up to 30% reduction.
• If overcooling is enabled, the control will engage a 1 degree of overcooling for each 10% of RH
error. A maximum amount of overcooling can be configured to 1, 2 or 3 degrees.
• Fan off delays will be eliminated.
Smart Continuous Fan
Continuous fan operation will be interrupted when indoor relative humidity exceeds desired humidity
setpoint. A humidity icon will be displayed along with the fan icon to indicate that blower on options
have been disabled due to high humidity conditions. Smart Continuous Fan will not interrupt the fan
circulate mode.
Alert Code Diagnostics
Diagnostics are displayed as current alerts (what is currently happening in the system) and alert
history (what has occurred in the past, but are no longer present). The alert screen describes the alert,
when the alert happened, the severity level of the alert as well as a problem description and possible
causes to assist with troubleshooting. Up to the last 30 days are displayed.
Dual Fuel Options
The change over from heat pump to furnace can be set based on three options:
• Comfort –This is strictly based on indoor temperature demand. The furnace will take over when
the heat pump can no longer maintain the indoor heating demand.
• Operating Cost –The HSPF of the heat pump and AFUE of the furnace must be entered along
with cost of electricity and fuel. The control calculates an economic balance point for system
change over.
• Outdoor Temperature –The changeover from heat pump to furnace is based on outdoor
temperature which can be set from 0–70° (thermal balance point).
The furnace will take over anytime the HP is unable to maintain indoor temperature, regardless
of the dual fuel option chosen.
Emergency Heat
The heat pump will be disabled and the furnace / heat strips are enabled any time the control is set to
Emergency Heat.
Fan Options
There are three options available for blower operation:
• Auto –the blower runs when there is a call for cooling or heating.
• On
–the blower will run continually with a fan only call. The continuous fan speed for variable
speed motors can be adjusted from 35%–100%. A call for heating or cooling will supersede a fan
only call and the blower will run at a speed that matches the staging of the equipment.
• Circulate –this provides all the features of “fan on”, but the blower will only run a percentage of the
time when there is no call for heating or cooling. The blower can be set to circulate from 10–55
minutes of every hour.
History Screen
The History Screen provides system cycle information. Cycle counts and run time can be viewed for
first stage and second stage compressor operation, W1, W2 & W3 heating and defrost cycles. This
information can be viewed in a 24 hour, 1 week or 1 month period.