Some of the most common applications of HVAC drives like the ACH580s are utilised, and involve an Auto-Off-Manual switch. Examples include car park exhaust fans, kitchen exhaust fans, and cooling tower fans. In this Tech Tip, you will find the basic parameter configurations needed for your Auto-Off-Manual application.

In this example, a 3-position switch is used to change between auto, off, and manual modes, with the switch wired to DI1 and DI6. In auto mode (DI1), the drive will run using an analog input as a frequency reference, such as a CO sensor or pressure sensor. In manual mode (DI6), the drive will run at a constant frequency of 50Hz.

Navigate to the complete list of parameters by pressing Menu >Parameters > Complete List.

Group 12 (Standard AI)

12.15: AI1 Unit Selection | V

12.17: AI1 min | 0.000

12.18: AI1 max | 10.000

12.19: AI1 Scaled at AI1 Min | 0.000

12.30: AI2 Scaled at AI2 Max | 50.000

Group 19 (Operation Mode)

19.11 Ext1/Ext2 Selection | DI6

Group 20 (Start/Stop/Direction)

20.01 Ext1 Commands | In1 Start

20.03 Ext1 In1 Source | DI1

20.06 Ext2 Commands | In1 Start

20.08 Ext2 In1 Source | DI6

Group 28 (Frequency Reference Chain)

28.11 Ext1 Frequency Ref1 | AI1 Scaled

28.13 Ext1 Frequency Function | Ref1

28.15 Ext2 Frequency Ref1 | Zero

28.17 Ext2 Frequency Function | Ref1

28.22 Constant Frequency Sel1 | DI6

28.26 Constant Frequency 1 | 50Hz

And you're done! There may be some minor application-specific tweaks required, however, you should be well on your way to getting your application up and running.