Typical Outdoor Mode Installation Steps - heat-timer SMC Installation & Operation Manuals

The difference between these two is called the Slab ΔT. The Slab ΔT is different for each slab composition
based on the slab design. The higher the Slab ΔT, the more energy is being input to the slab. If the Slab ΔT
is set larger than its design ΔT (Max ΔT), the slab itself may be damaged. The SMC provides a Maximum
Slab ΔT adjustment. This setting protects the slab during the initial warm-up periods. See "Maximum Delta
Temperature (Max ∆T)" on page 29.
After the warm-up period, each slab has a heat loss that varies with the outdoor temperature changes.
Therefore, a slab might require 130°F fluid temperature at 0°F outdoor temperature to maintain its heat.
However, when the outdoor warms to 15°F, it might require only 100°F fluid temperature circulating. The
SMC has a Heating Curve adjustment to insure the slab temperature is sufficiently warm to melt frozen
precipitation once the warm-up period has ended. The curve value compensates for the different slab types
and different outdoor weather conditions. After making a change in the Heating Curve value, it is necessary
to wait at least four hours before assessing the effect it had on slab temperature. See "Heating Curve" on
page 26.

TyPICAL OUTDOOR MODE INSTALLATION STEPS

To install and set the control to operate based on the Outdoor Sensor follow these steps:
• Install the SMC control indoors. See "Mounting the Enclosure" on page 9.
• Install and wire the Slab Supply, Slab Return, and the optional Boiler Return Sensor in their wells. See
"Water Temperature Sensor Installation" on page 11.
• Install and wire the Outdoor Sensor. See "Outdoor Sensor Installation" on page 11.
• Wire the power to the SMC. But do not turn on circuit breaker. See "Wiring the Power" on page 12..
• Wire the SMC outputs to the System and Slab Pumps, Motorized Valve, and Boiler. See "Output Wiring"
on page 12.
• Power the SMC.
• Set the following SMC System Startup settings:
○ Sensor Type =
○ Control Mode =
• As a starting point the following SMC Operating settings needs to be set:
○ WWC
○ CWC
○ Maximum Delta T
○ Maximum Slab Supply
○ Minimum Boiler Return =
○ Season
SMC Installation and Operation Manual
Outdoor. See "Sensor Type" on page 22.
Select Motorized Valve if the slab loop is using a 2-way or 3-way
motorized valve.
Select Boiler if the slab loop is heated directly by a modulating boiler.
Select Ext. Interface if the SMC is connected to a multi-boiler control
(Multi-MOD Platinum, Mini-MOD, SQ-Elite, etc..). Then set the EMS
4mA and 20mA set points to match the multi boiler control 4-20mA set
points. See "Control Mode" on page 22.
= 38°F . See "Warm Weather Cutoff (WWC)" on page 26.
= 10°F or as per engineers criteria. See "Cold Weather Cutoff (CWC)" on
page 28.
= As per slab design engineer. See "Maximum Delta Temperature (Max
∆T)" on page 29.
= As per slab design engineer . See "Maximum Slab Supply" on page 29.
As per boiler manufacturer specifications. See "Minimum Boiler Return"
on page 29.
= Winter. See "Season" on page 26.
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