Hi,

What is illuminating the red 'fault' lamps for the supply fan and return fan?

This could be a thermal overload that has tripped on the associated fan starter circuits within the control panel. It could be variable speed drives for the fans that are in 'fault' and need to be manually reset.

Regards,

Hi,

Some questions / notes below:

1. On your control panel, what is illuminating the red 'fault' lamps for the supply fan and return fan?

2. As you are running both fans in manual (MAN) at the control panel, the VFD shows the fan is running, but is only running at 10Hz, which is most likely the minimum speed that has been configured in the VFD settings. 

3. When you switch from manual to auto on the control panel switches, what happens? If the answer is 'nothing', then something in the software of the controller may be inhibiting the operation of the fans.

4. As the fans can run when set to manual at the control panel, this shows the any electrical safety interlocks are 'healthy'. So, it would appear the issue may be with a software interlock. First, you need to understand what's causing the issue in point 1 above with the red lamps.

Regards,

Hi,

Sorry to keep asking, but on your control panel, what is illuminating the red 'fault' lamps for the supply fan and return fan?

It may be the case that the software is inhibiting the operation of the system due to this. If so, this is why the system starts in manual, but not in auto.

Regards,