Friedrich Floating Air Pro Multi-Zone FPHMR42A3A Service Manual page 190

OPERATION
Outdoor Unit Control Mode
7. Outdoor four-way Valve Control
Four‑way valve of the outdoor machine shuts down when cooling but starts when heating. The operation of heating defrosting
refers to defrosting operation and, when the heating remote shutdown, the four‑way valve disconnects in 50s when the
compressor stops working.
8. Start-up Protection
To prevent compressor from restart frequently in the condition that system pressure has not been completely balanced, it
can't be restarted within 3 minutes.
9. Pressure Protection
Pressure switch is normally kept open. When the pressure grows too high, the pressure switch will close and will enter
pressure protection control. The frequency will automatically decrease. If the pressure is still unable to return to normal
condition after decreasing frequency, compressor will stop and report the fault code of pressure protection.
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