Using the plant screen

1. The mark in the header

The crosshair and the words Fixed Point / Engineering are the company mark, the same one as the jobs app. The amber chip says Concept / Simulation: this page is not talking to a panel.

2. Safety strip

Fire alarm, e-stop, frost stat, and refrigerant leak should all read Healthy. Open “Simulate a safety trip” and press one. The fans stop, the dampers close, and the alarm latches.

Frost also drives the LTHW heating valve to 100%. Restore the inputs, then Reset lockout. Reset is refused while a contact is still open.

3. Start sequence

After a reset, with the plant occupied, the screen opens the dampers, starts the supply fan, waits for airflow to prove, then starts the extract fan. Until supply airflow is proved, the extract fan stays off.

4. Air path

Left to right, then the next row: outside temperature, fresh air damper, panel and bag filters, heat recovery, LTHW heating coil, CHW/DX cooling, supply fan, supply air temperature and humidity.

The return strip is the extract fan and filter, extract temperature and humidity, and room CO₂.

5. The bag filter alarm

“Supply bag filter dirty” starts unacknowledged. Acknowledge it. It stays in the list while the switch is still dirty, marked acknowledged. Toggle the bag filter in the concept tools to clear the switch.

6. Setpoints, hand, auto, off

Supply temperature and CO₂ are the two loops on this concept. Fan speed sits between 30% and 100% as CO₂ climbs above 800 ppm. Heating and cooling are sequenced with a 1 K deadband. At 80% RH, cooling is held back.

Auto follows that. Hand holds the slider. Off forces the output off. A safety trip overrides hand.

Unoccupied stops the plant. A weekly timetable comes later; this demo stays on the button you press.