User manual

Chapter 4: Programming your SEC-HD Phason

Chapter 4: Programming your SEC-HD

What you need to know before programming

Programming the SEC-HD basically means telling the control what you want it to do with the

equipment and when you want it done. For example, for a single-speed fan set for cooling, you

might say "Switch ON when the temperature reaches 80°F."

Before you begin programming your SEC-HD, make sure:

 The control has power

 You know which equipment is connected to which stages

 You have

properly connected

all equipment to the

correct terminals

 You have properly configured and tested all equipment connected to the variable and relay

stages. For more information, read Chapter 3: Configuring your SEC-HD on page 20.

Use Appendix F: Settings worksheets on page 57 when programming your SEC-HD.

Understanding how the SEC-HD operates

Understanding how the SEC-HD operates can help you configure and program your control more

efficiently, and control your environment more effectively.

The configuration and settings for the following example are the factory defaults for program A.

Group set point is the target temperature for the room.

Stage 1 idle speed is the speed, in percentage of full power, at which the stage 1 fan operates

for minimum ventilation.

Stage 1 idle range is the temperature below which the stage 1 fan is off and the inlet is closed.

When the temperature is between the

Stage 1 idle range

and Stage 1 set point, the fan operates at

Stage 1 idle speed.

Stage 1 set point is the temperature above which the stage 1 fan speed increases toward its

maximum. You should set the Stage 1 set point to the same temperature as the Group set point.

Stage 1 differential is the temperature at which the stage 1 fan reaches full speed.

Stage 2 idle speed is the speed at which the stage 2 fan operates when the temperature is at the

Stage 2 idle range (parameter 7).