Steffes 6140 - Manual (Page 7)

Operation
TEMPERATURE CONTROL
Temperature set point is adjusted at the wall thermostat(s) or the main system control. If temperature in the area
drops below the desired set point, a heat call is initiated and the blower is energized. The variable speed core
blowers automatically adjust speed in relation to brick core temperature and duct temperature to circulate air
through the brick core. The supply air blower then delivers the heated air into the desired area through the duct
system to satisfy heating requirements.
When used to supplement a heat pump, the Comfort Plus Commercial system replaces resistance strip heat,
which is typically required as a supplement or back-up to the heat pump. The discharge air sensor monitors the
outlet air temperature. If the demand for heat is at a point where the heat pump alone cannot maintain the desired
duct temperature, stored heat is used to supplement the heat pump and satisfy the heating requirements.
When the system receives a “G” call, the supply air blower is energized; however, no heat is delivered as this is a
“fan only” call. When a “G” call is received with a “Y” call, the supply air blower is energized and the minimum
discharge air temperature (as set in Location 48) is targeted.
Anytime the system receives a “W/Aux” call with any other call from the thermostat (except “O”) then the
maximum discharge air temperature (as set in Location 49) is targeted. The maximum discharge air temperature
is also targeted if the current outdoor temperature (shown in Location 109) is lower than the off-peak lock out
temperature (set in Location 46) or the on-peak lockout temperature (set in Location 47). If an "O" call is received
from the thermostat, the system will go into cooling and will not charge.
Reference Supplemental Installer's Guide for more information on system operation.
BRICK CORE CHARGE CONTROL
The amount of heat stored in the brick core varies in relation to outdoor temperature, current building load, utility
peak conditions, and/or the heating requirements. The outdoor sensor, if used in the application, monitors outdoor
temperature and provides this information to the system. As the outdoor temperature decreases, heating require-
ments increase and the system stores more heat accordingly.
The amount of heat stored in the system can also be regulated by a signal from a BACnet
control, energy management system, or serial communication input.
CHARGE CONTROL OVERRIDE
If desired, the Comfort Plus Commercial system can be programmed to allow a charge control override. This
override allows the user to force the system to target a full core charge level and can be initiated or cancelled at
any time. If an override is initiated, the system targets a full core charge level during the next charging period. It
continues to charge during uncontrolled hours until it achieves full (maximum) core charge or until the override is
cancelled. Once full charge is achieved or the override is cancelled, the system charges according to the standard
configuration.
Charge control override does NOT override a peak or load management control signal.
MAINTENANCE AND CLEANING
The Comfort Plus Commercial heating system is easily maintained. The air filter in the return air duct of the
system should be replaced on a regular basis to ensure proper operation and to maintain overall efficiencies. No
additional routine maintenance is required.
If utilizing a heat pump or air conditioning system with the Comfort Plus Commercial, the indoor coil of the device
should be cleaned periodically as dirt accumulation may reduce system efficiency. It is important to follow the
manufacturer’s maintenance and cleaning recommendations for these devices.
Comfort Plus Commercial Operation
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